Low back pain is the most common health problem that affects work performance and quality of life. Non-specific low back pain (NSLBP) is defined as low back pain not attributable to a recognizable, known specific pathology. NSLBP is the leading cause of disability among the major musculoskeletal conditions which leads to Impairments, Activity Limitations and participation restrictions. Therefore it becomes a psychosocial/economic burden on individuals, families, communities, industries and government. Existing literature shows globally 40% to 50% of people have LBP at some point in their lives and there exists a challenge in Africa on the best rehabilitation methods for low back pain management which could prevent chronic pain and disability. Therefore, this study aims to determine the effectiveness of MET when combined with DSE in the management of chronic NSLBP patients and to analyze the additional effect the MET procedure will provide relative to DSE.

Low back pain (LBP) is arguably the most prevalent musculoskeletal condition found among both developed and developing nations. Broadly defined as pain or discomfort in the lumbar region of the spine it is the leading cause of activity limitations, resulting in significant losses in productivity at work and incurs billions of dollars in medical expenditure annually. The prevalence of LBP worldwide is estimated to be between 30 and 80% among the general population and has been found to increase with age. In addition, a higher prevalence of LBP has been associated with lower socioeconomic status and lower education levels. According to the Global Burden of Disease (GBD) 2010 study, LBP is currently the 6th highest burden on a list of 291 conditions and is the cause of more years lived with disability globally than any other disease. Affecting just about anyone, of any gender, race or socioeconomic background, LBP has a substantial impact on the overall and financial well-being of an individual and society.

Therefore, it was postulated that the burden of LBP would be greater in lower and middle-income countries like those situated in Africa. A recent systematic review and meta-analysis published in 2018 revealed that the lifetime, annual and point prevalence of LBP among African nations, was higher than the global LBP prevalence. The majority of the studies included in this meta-analysis were conducted in Nigeria, which is a lower-middle-income country. In Nigeria, the annual prevalence rate of LBP has been reported between 33% and 74%, mostly affecting workers. The prognosis after an acute episode of LBP is less favourable than once thought, as 60-80% of the patients will experience recurrence or persistence of this disabling condition.12 Despite the high incidence and prevalence of LBP, little is known about the precise causes. As a clear pathoanatomic diagnosis cannot be identified in 85% of the patients,13 LBP in these patients is labelled as non-specific (NSLBP).

Despite extensive research, the issue of spinal pain management still constitutes a challenge for physicians, physiotherapists, and researchers. There are many therapies claimed to be useful for the treatment of NSLBP, but most of these treatments have not been well investigated or have been found to have modest effects in terms of pain relief and improving disability. Conservative treatment remains the best choice and usually involves physiotherapy. Exercise therapy is one of the most used treatment strategies as it has shown to be effective in decreasing pain and disability, and can even induce functional changes of the back muscles. Although, exercise therapy in highly recommend by experts in treatment guidelines, the evidenced treatment effects remain low to moderate. It is, therefore, useful to further explore the effectiveness of treatments that may assist people with NSLBP. Another, non-invasive, safe and inexpensive treatment technique used by physiotherapists, osteopaths, chiropractors and manual therapists in the treatment of NSLBP is Muscle Energy Technique (MET). MET involves alternating periods of resisted muscle contractions and assisted stretching. Although it has been suggested that MET can be used to lengthen a shortened muscle, mobilize an articulation with restricted mobility, strengthen a physiologically weakened muscle and reduce localized oedema and passive congestion, the physiological mechanisms underlying the therapeutic effects of MET are currently unclear. Mechanisms of altered proprioception, motor programming and control have been proposed, but research is required to confirm these hypotheses. While MET is often used for the treatment of NSLBP, a recent Cochrane review concluded that there is lack of empirical evidence on its effectiveness in the management of chronic NSLBP. These conclusions were made not because of the lack of treatment effectiveness, but because the currently available studies have been generally performed in too small study samples and have a high risk of bias, producing unreliable answers about this therapy. In conclusion, the Cochrane review emphasized the need for larger, high-quality studies to determine the effectiveness and safety of MET in chronic NSLBP.

Therefore, the aims of this study are to determine the effectiveness of MET when combined with DSE in the management of chronic NSLBP patients and to analyze the additional effect the MET procedure will provide relative to DSE. Thus, the efficacy of the combination of MET plus DSE will be compared with outcomes of treatment with DSE or standard physiotherapy (SP) in the management of chronic NSLBP. The study will evaluate the effect of each intervention on trunk Range of Motion (ROM), muscle functions (limited to muscles strength, endurance, force and Maximal voluntary contraction [MVC]), Quality of Life (QoL), functional disability, activity limitations and participation restrictions.

The primary goal of this study is to evaluate the effects of MET in combination with DSE on quality of life and trunk muscles functions in patients with chronic NSLBP, however, the study involves the following as general goal that needs to be realized;

1. To conduct a systematic review (scoping) of the literature on the effectiveness of MET in the management NSLBP.
2. To cross-culturally adapt and psychometrically validate the Nigerian Hausa Version of Örebro Musculoskeletal Pain Screening Questionnaire.
3. To conduct an online survey to determine the knowledge and skills of Nigerian physiotherapist on the application of MET in the management of NSLBP.
4. To evaluate the working mechanism of MET on the trunk muscle function by studying several muscular properties (recruitment, endurance, fatigability, flexibility) in chronic NSLBP.
5. To conduct a randomized control trial (RCT) to determine the short-term (6 weeks, 12 weeks) and long term (3 months) effectiveness of MET in combination with DSE on back muscles function and on clinical outcomes of functionality (such as disability, quality of life, and activity and participation restrictions) in patients with chronic NSLBP.

Therefore, the RCT component of this research has the following objectives.

1. To determine the effectiveness of MET in combination with DSE in the management of chronic NSLBP patients by assessing their influencing on trunk muscles functions limited to trunk muscles endurance, Transverses abdominus muscles contraction rate, trunk ROM, QoL, functional disability, global rating of change scale (GROCS), activity limitations and participation restrictions.
2. To evaluate the additional effect of MET relative to DSE on the study outcomes in the management of chronic NSLBP patients.
3. To compare the therapeutic effect of MET plus DSE with outcomes of treatment with DSE or standard physiotherapy (SP) in the management of chronic NSLBP
4. To assess all outcomes at baseline, 6th week and 12th week of the study interventions.
5. To also conduct a 3 months follow-up evaluation on outcomes to determine if the intervention effect is retained within the period. The ultimate goal is to provide recommendations (based on the study findings) for the implementation and use of MET in the Nigerian Health Care System for the management of chronic NSLBP.

Inclusion Criteria:

1. NSLBP history of about or more than 3 months and associated with referred lower extremity pain; pain in the lumbopelvic region;
2. Lumbar hypomobility; mobility deficits of the thorax and hip regions;
3. LBP not of specific origin diagnosed by a physician (due to fracture, tumours, malignancy, ankyloses, infections, and pregnancy);
4. Diminished trunk or pelvic region muscle strength and endurance;
5. Movement coordination impairments while performing community/work-related recreational or occupational activities.
6. Attending Outpatient clinics and Physiotherapy departments of Rasheed Shekoni Teaching Hospital Dutse and Federal medical centre Birnin-Kudu in Jigawa state, Northwest Nigeria.

Exclusion Criteria:

1. Chronic NSLBP with radiating pain due to nerve root involvement in physical examination.
2. Patients using immunosuppression or steroid medication.
3. Patients with persistent severe pain.
4. Patients with spinal deformities.
5. Patients with widespread neurological symptoms; patients with peritonitis as at the time of recruitment; patients with a history of lumbar surgery; patients diagnosed with carcinoma or organ disease; and patients with a history of severe rheumatic, orthopaedic, cardiovascular, systemic, metabolic or neurologic disorders.

We have not yet decided whether to share IPD, but we will when we find it convenient

All eligible participants will be randomly be allocated to three groups using a random number generator by an independent person (third party). Two study assessors will take measurements of all outcomes at baseline, 6th and 12th week and 3 months follow-up, however, they will be blinded to group allocation. Group indication will be placed in a sealed envelope that will be opened after the study assessors have performed the initial assessments and the participants will be instructed not to disclose their study groups to the assessors. However, participants are expected to be unaware of their group procedure/intervention, therefore, the physiotherapists will be instructed not to disclose the name of their group procedure to the participants.