From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:de]From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:fr]From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:es]From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:ja]From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:it]From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:pb]From Roger Pierce:

Connective Tissue Connective tissue is characterized by the presence of intercellular substance. amorphous and fibrous, and is the most ubiquitous tissue of the body. It participates in the supply function of circulation, the supportive function of the skeleton and the locomotor function of the musculature.

1. Support. “Me human body is an edifice of nonliving intercellular substance on and in which cells live as residents” (Ham, p. 205). This supportive capacity varies widely, depending on the firmness of the amorphous substance, the presence and type of fibres (collagenic, including reticular, and elastic) and the presence or absence of impregnated calcium salts. In the central nervous system this supportive function is served by the glial cells. Organs are encapsuled in connective tissue, which sometimes also forms their flexible skeletons.

2. Nutrition. Connective tissue constitutes the vascular system, including not only the blood and distribution ducts but the loose connective tissue whose fluid provides the diffusion medium for the transfer of nutrients, wastes and gases between the blood and lymphatic capillaries and the cells. Hence no other cells of the body can exist except in proximity to connective tissue. Aging is partly characterized by a decrease in the proportion of amorphous or ground to fibrous substance, presumably impairing the permeability of the tissue by nutrients and wastes.

3. Defense, through the activities of mobile plasma cells and macrophages.

4. Storage of energy in the form of fat, particularly in adipose tissue.

5. Self regeneration, chiefly by the fibroblasts, sometimes by mesenchymal cells which have retained their primitive uncommitted character.

There are three main kinds of connective tissue; hemopoietic, which is mostly cells; dense, which includes dense ordinary (articular capsules, ligaments, tendons and fascia), cartilage and bone; and loose ordinary, that which accompanies the vascular system.

Fascia

“Fascia is a kind of biological fabric” (Frost, p. 69), a dense connective tissue which takes two forms. Superficial fascia is a fatty subcutaneous layer which insulates the body, binds the skin to the deep fascia with varying degrees of firmness and provides a bed for vessels and nerves. Deep fascia is dense and tough and lacks fat; it forms a sheath around muscle groups (investing fascia and septa), muscles (epimysium), fascicles (perimysium) and fibres (endomysium). At the ends of muscles the fascial linings continue beyond the muscle fibres to form tendons which attach to bone or too ther fascia or to ligaments. Tendons are somewhat elastic, buffering the bones from the shock of quick muscular action and adding a recoil force. Tendons may be long if the muscle needs only short fibres but its attachments are far apart, or if the body of the muscle is best located at some distance from the joint (as in the hand and foot); and tendons may change the direction of action by crossing notches or pullies such as the retinaculae, which are themselves fascial.

Since fascial sheaths invest the muscles, they present their surfaces to each other, providing a gliding medium similar in function to the double-walled pericardium and pleura except that the fascia, by penetrating the muscle, is in effect continuous with the organ itself. And since fascia is a continuous structure of such sliding sheaths, one blending with and/or forming attachments for another (there being much more muscle attached to fascia than to bone), condensing into tendons or spreading into aponeuroses, the network provides not only the medium through which the circulatory and nervous systems proliferate, but another communicating system. Because of fascia the movement of, say, the forearm is spread out, anchored, adapted to and refined by the whole trunk ultimately the whole body. One can think of the fascia network as a mediation between skeleton and musculature, sharing the supporting function of the one and the locomotor function of the other. It is difficult to imagine what a graceless, mechanical pattern of movement would result if muscles attached only to bone and there were not the infinite possibility for refinement of control that the fascial system affords, matching, perhaps, the incredible refinement of the nervous system. It is through fascia that the respiratory movements spread their effect through the whole trunk, permitting a wide muscular participation with all its beneficial side effects.

Structural Integration works indirectly on the other systems of the body by working directly on the fascia, first the superficial in order to stimulate circulation (and therefore metabolism) and to open it in order to free the structures it limits and to reach the deep fascia. Then stretching the deep fascial fibres to restore resilience (presumably by altering the proportion of fluid in the tissue) and freeing sheaths from their neighbors so that refinement of individual muscular action is permitted and the muscle can lengthen.

The Skeletal System

Bone is designed for resistance to both compression and tension, for elasticity, and for lightness. Hence it is both organic, a system of isolated osteocytes, and mineral, chiefly calcium phosphate. The mineral constituents also constitute a storehouse for other tissues. Bone can be either dense or spongy, depending on local stresses; spongy bone is characterized by trabeculae which reinforce lines of tension and compression stress. The shafts of long bones are built of dense bone, taking a tubular shape for lightness. The hollow centers of some bones are the sites of hemopoiesis, the formation of erythrocytes from hemocytoblasts. Osteoblasts and osteoclasts give to bone itscapacity to grow, to repair itself and to change shape and strength in response to stress. Bones are invested with a sensitive, tough, fibrous vascular periosteum which supplies nutrients and fibroblasts.

Cartilage is an a vascular elastic, pliable dense connective tissue nourished by diffusion from its perichondrium, which also replenishes its cells (chondroblasts developing into chondrocytes). Hyaline cartilage lines articular surfaces; because of its pliability it absorbs shocks and its glossy surface, lubricated by synovial fluid, provides a sliding contact. Elastic cartilage, as in the auricle, contains a high proportion of elastin; fibrous cartilage, as in the intervertebral disks and the pubic symphysis, has more collagenous fibres and few chondrocytes.

Skeletal ligaments are bands of collagenous tissue that bind bones or bony parts. They frequently provide a structure around joints to limit range of movement and afford attachments for tendons.

The skeleton is the weight-bearing system of the body. It also provides protective cavities for the central nervous system and viscera and furnishes muscular levers for locomotion. As an anti-gravity structure the skeleton balances the head on its axis, supports the thoracic cage laterally and employs the four spinal curves in order to mediate the two kinds of stress (axial and shearing/bending). The spine represents a compromise between these various functions, being a pyramidal stack of 33 or 34 closely articulated separate bones (except in the fused sacral and coccygeal region), separated by liquid-filled fibrocartilagenous disks which absorb shock and furnish a rocking articulation. The spine is given its elastic rigidity by an elaborate system of ligaments, tendons and large and small muscles anchored to the bodies and processes of the vertebrae. The spine provides support via the sternoclavicular joint and costal cartilages for the thoracic cage and shoulder girdle, which in turn anchor the upper appendages. Weight is transferred to the lower extremities via the pelvic arch (sacroiliac joint and acetabulum to head of femur).

The basic compromise between weight bearing and locomotion is in the high center of gravity of the system; the narrow base and small moment of inertia create a system in unstable equilibrium. This is a touchy system which, with minimal initial energy can initiate massive movements in any direction without muscular preparation (i.e. resistance to weight). This shape of the skeleton reflects the relationship between the nervous system and the musculature: a very delicate low-energy (and perhaps for that reason very sophisticated) triggering mechanism can activate the massive musculo-skeletal system because it is poised for movement. “In the unstable balance the center of gravity is as high as possible and the potential energy is maximum” (Feldenkrais, p. 76).

The Muscular System

Muscles are tissues that specialize in contraction, that is, movement. They are of three kinds. Smooth (involuntary, visceral) muscle has an irregular organization of action and myosin filaments, has slower and weaker but more sustained contractions, and is capable of spontaneous contraction. It is found in the walls of hollow organs and its chief function is to maintain tonus. Cardiac muscle has short branching fibres and is specialized by inherent rhythmicity, a very slow repolarization rate (hence a long refractory period which protects its rhythmicity) and a very rich vascular supply augmented by the presence of myoglobin in the sarcoplasm.

Skeletal (striated, voluntary) muscle is made up of large and sometimes very long cells (fibres), filled with myofibrils and enclosed in a sarcolemma. The unit of contraction, the sarcomere, is a section of myofibril in which actin and myosin filaments, activated by conversion of ATP into ADP (more broadly, glycogen into lactic acid) interdigitate and are bound by cross bridges.

Muscle fibres are innervated at a motor end plate by release of acetylcholine, increasing membrane permeability and the flow of sodium ions. Muscle cells transmit the action potential in the same manner as neurons. A single efferent neuron may innervate as few as one or as many as 140 non contiguous muscle fibres, forming a motor unit which will fire together. Each fibre either contracts entirely or not at all, but fibres have variable liminal thresh holds. A stronger contraction may be brought about by strengthening the nervous impulse, by summation (the refiring of the cell at the end of its refractory period) and by bringing more motor units into play. Tonus is maintained by rotating contractions between motor units.

Striated muscle cannot function without neural stimulus, and the structure of the musculo skeletal system is finely tuned to its innervation. For example, the timing and force of contractions on a given long bone combine to minimize bending, and where the forces are unequal, as in the femur, the normal bowing of the bone will compensate.

The stretch reflex, a tendency of muscle to resist stretch, is a basic mechanism in maintenance of erect posture, acting in the extensors of the weight-bearing joints. The stretch reflex can be inhibited, as in reciprocal innervation.

Skeletal muscles move bones around joints. Those muscles which lie entirely within a given region (opponens pollicis, intercostals, sterno hyoid) are called intrinsic muscles; those which extend beyond (abductor pollicis longus, pectoralis major, trapezius) are extrinsic. Intrinsic muscles are generally deeper and more refined than extensors, and rolfers move from the latter to the former in sequence. Most muscles are third class levers, i.e. the force is exerted between the fulcrum (the joint) and the weight so that the weight arm is longer than the power arm and power is sacrificed to range and speed. Muscles nearly always act in concert as synergists, strengthening a movement or eliminating unwanted increments of movement by the action of other muscles. There is often a mobilization of the whole musculature for actions in one region. For example, lifting a weight in the hand involves stabilizing by elbow and shoulder flexors and extensors of the back, hip, knee and ankle in order that the acting muscle may get its grip on the ground.[:]Making of a Rolfer – From Roger Pierce