Effect of Low Blood Flow Restriction Training on Nonspecific Low Back Pain Patients

Low back pain (LBP)-related disability and the related socioeconomic burden remain high despite the many treatment options and health care resources available for LBP. LBP can be caused by a specific pathology or trauma; however, in >90% of cases, an underlying disease is absent. The clinical course of this called as nonspecific LBP which is the most common type of low back pain and, some patients recover within weeks, and others experience persistent disabling symptoms leading to chronic LBP. Chronic low back pain (CLBP, pain lasting more than 12 weeks duration) is one of the most common chronic musculoskeletal disorders with high prevalence rates worldwide. Patients with CLBP have varying degrees of pain in the lumbar region of the spine, generally located between the lower ribs and the gluteal region.

Approximately 85% of patients have chronic non-specific low back pain (CNLBP) who do not have a specific patho-anatomical cause attributable to their pain in clinical examination. More than 50% of people in the United States are affected by CLBP. 90% adults will experience LBP in their lifetime, and the recurrence of LBP following chronic episode ranges from 24 to 87 %. The prevalence of LBP in children and adolescents has reaching around 39% of LBP lifetime prevalence in adults at 18 years of age. The prevalence of low back pain was 55.51% in Lahore, Pakistan.

Common nonspecific LBP symptoms include paravertebral muscle spasms, tight hamstrings, trigger points in the muscles, limited spinal range of motion, discomfort and pain. CNLBP is the most common musculoskeletal condition impacting performance leads to functional disability. Various factors associated with CLBP, including smoking, excessive BMI, poor muscle endurance, occupational ergonomic factors, poor posture, altered muscle firing rates, muscular imbalance, psychological factors as depression, inflexibility of the lower extremities, and leg length discrepancies.

Muscle tightness linked to postural disturbances and reduced extensibility resulting from increased hamstring stiffness could be a possible contributing factor to low back pain. Tight hamstring draws the pelvic into posterior rotation with greater flattening of lumbar lordosis which increase mechanical stress on the spinal soft tissues and altered hip biomechanics and lumbopelvic rhythm. If hamstrings are tight, then blood supply will be squeezed out of them leads to decreased muscle capacity, deconditioning and reduced strength which may cause abnormal changes in the bodily posture lead to lumbar hypo-lordosis causing LBP.

Chronic low back pain involves complex interaction of neuromuscular, inflammatory and neurophysiological processes that leads to constant pain. Long-term alterations in movement patterns due to muscular tightness result in structural changes within muscle fibers. The mechanism involved behind is arthrogenous muscle inhibition that inhibits alpha-motor neurons leading to decreased activation of stabilizing muscles. At molecular level, Peripheral and central sensitization contribute to LBP by releasing inflammatory mediators (substance P, bradykinin, cytokines and histamine) and by enhancing the excitability of spinal neurons respectively. Impaired neural drives alter proprioceptive feedback signals linked with increased adipose infiltration, reduced muscle quality, and diminished muscle efficiency.