Chronic low back pain is among the most burdensome of health problems in prevalence and cost of care [1]. It is the leading cause of years lived with disability worldwide and the most frequent cause of functional loss in high-income countries [2, 3]. Much of the economic burden is expended on costly surgical and rehabilitative services. Up to onethird of acute low back pain cases may become chronic and lead to disability [4]. In a majority of chronic cases (estimated at 85–95%) a definitive diagnosis, that is, infection, neoplasm, osteoporosis, arthritis, fracture, radiculopathy, or inflammatory rheumatic processes, is ruled out, and these are designated as chronic “uncomplicated,” “mechanical,” Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2015, Article ID 813418, 19 pages http://dx.doi.org/10.1155/2015/813418 2 Evidence-Based Complementary and Alternative Medicine or “nonspecific” low back pain (CNSLBP) [5]. There is no consensus on the optimal approach to the treatment of CNSLBP. Management typically includes some combination of analgesic or anti-inflammatory medication, directed therapeutic exercise, manipulation, cognitive-behavioral therapy, and patient education [6]. Systematic reviews have generally concluded that the benefits of these approaches are limited and mostly short-lived [7–11]. A large survey in the United States found that 54% of patients with low back or neck pain used complementary therapies and that approximately onethird of all visits to alternative care practices were for back or neck pain [12]. Low back pain has been reported to be the primary complaint in 40% of all visits to chiropractors, 20% to massage therapists, and 15% to acupuncturists [13]. Structural Integration (SI) is an alternative manual therapy that is increasingly available and sometimes resorted to for the treatment of chronic musculoskeletal pain and disability. Developed by the biochemist Ida Rolf outside of orthodox medical science, it has been propagated as an alternative therapy since the mid-1950s. A few preliminary studies of low quality with small samples suggest effectiveness for musculoskeletal pain, but aside from a single case report, no clinical studies of SI for CNSLBP have been published to date [14–16]. The musculoskeletal pain studies and preliminary evidence regarding a number of hypothesized therapeutic mechanisms have been reviewed elsewhere [17]. The experience of SI treatment sometimes involves notable discomfort which has led to a reputation of being excessively painful and even to concerns as to its safety [18]. This has been a barrier to a more widespread adoption by conventional clinical services, although SI was successfully incorporated into at least one [15, 19]. Despite these concerns, published data on adverse events (AE) associated with SI are limited to a single case and a small prospective case series [20, 21]. This study was designed to collect preliminary data on the feasibility, effectiveness, and AE associated with SI as an adjunct to outpatient rehabilitation (OR) versus OR alone for CNSLBP. The outcomes will inform the design of a more adequately powered clinical trial. We hypothesized that we could recruit and retain qualified participants who would comply with treatment regimens and data collection, that a course of SI + OR would improve low back related pain and disability significantly more than OR alone, and that SI could be delivered with acceptable levels of AE.