Low back pain (LBP) is a relevant public health problem, being an important cause of work absenteeism worldwide [1–3], as well as affecting sufferers’ quality of life [1] and individual functional performances [1]. Non-specific chronic LBP (cLBP), which does not have a well-defined etiology and presents pain for at least 12 consecutive weeks, represents up to 95% of the cases of LBP [1]. The annual direct costs of cLBP in the United States range from 12.2 to 90.6 billions of dollars, and represent only 14.5% of the total costs of this health condition [4]. Life-time prevalence of cLBP ranges from 11 to 84%; 1-year prevalence ranges from 22% to 65%, and point-prevalence from 12% to 33% [5].
The European Guidelines recommends the use of supervised active exercises, manipulation/mobilization, Back Schools, multidisciplinary approaches and cognitive-behavioral therapies for patients with cLBP [1]. Evidence suggests that supervised exercise and cognitive behavioral therapies improve pain and reduce functional disability [6].
Strengthening exercises for abdominal and trunk muscles, motor control exercises for lumbar multifidus (LM) and transversus abdominis (TrA) and stretching exercises for trunk and lower limbs show some evidence of improvement of pain and functional disability in individuals with cLBP [1, 7, 8]. Strengthening exercises of abdominal and trunk muscles are based on the known association between weakness of the trunk and abdomen muscles and low back pain [9–14]. Weakness is a consequence of sedentary life, and is associated to paravertebral muscle hypotrophy [14] and changes in motor control [15]. Furthermore, deep muscles of the abdomen and trunk such as the TrA and LM are also affected in patients with cLBP [16]. Some studies have focused on the individual use of muscle stretching and strengthening or motor control in cLBP [17, 18]. However, Macedo and colleagues [19], on their systematic review, recommend motor control exercises associated with other types of exercise.
Cognitive behavioral therapy uses brief interventions and counseling strategies in order to facilitate behavioral changes [20], by modifying negative attitudes and beliefs [21]. The “Back Book” [22] may be used as a good educational support, since it offers evidence-based information that is consistent with biopsychosocial models. Cognitive-behavioral programs that showed some evidence for use in patients with cLBP include the Back Skills Training program (BeST) [21, 23], Brief Intervention (BI) [24, 25] and the Graded Activity [26].
The Graded Activity program, which was initially developed by Lindstrõm et al.[27], recommends the use of an individualized and submaximal exercise program, with educational support in order to enhance self-trust and tolerance to effort. Although it has been suggested that graded activity is effective in decreasing pain and functional disability in cLBP [26, 28], van der Giessen (2012), in a systematic review [29], concluded that there is insufficient evidence on the effects of graded activity in pain, disability and return to work in patients with non-specific cLBP. Furthermore, the Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability, and Health from the Orthopaedic Section of the American Physical Therapy Association[3] states that effectiveness of cognitive behavioral therapy in cLBP is moderate.
The literature is not clear regarding which exercise programs are most effective for patients with cLBP; therefore, more randomised controlled trials are necessary to clarify these questions. Moreover, little is known about the effect of graded activity compared with supervised exercise program (strengthening, stretching and motor control) in patients with non-specific cLBP.
The aim of this paper is to report the study protocol used to investigate the effect of two types of exercise program in reducing the symptoms of non-specific cLBP.








