Mechanical low back pain (LBP) stems from spinal structures or surrounding tissues, often caused by overuse or trauma, and is prevalent globally with high recurrence rates. Key contributing factors include biomechanical, psychological, and social elements. The latissimus dorsi (LD), along with other back muscles, plays a crucial role in lumbar stability via the thoracolumbar fascia. Stretching the LD has shown positive effects in reducing pain and improving function in chronic LBP patients. Physical therapy treatments include manual therapy, core stabilization, and flexibility exercises. Muscle Energy Techniques (MET), particularly targeting the LD, can enhance flexibility and spinal mobility when applied correctly.

Mechanical low back pain (MLBP) originates from structural components of the spine, such as intervertebral discs, muscles, ligaments, or joints, and is commonly caused by repetitive trauma, poor posture, or overuse. It is a leading cause of functional disability worldwide, with high recurrence rates. Physiotherapy plays a central role in managing MLBP by addressing contributing biological, psychological, and social factors. The latissimus dorsi (LD) muscle, due to its anatomical connection with the pelvis via the thoracolumbar fascia (TLF), significantly influences lumbar stability. Impaired extensibility or overactivity of the LD can contribute to mechanical dysfunction. Incorporating LD stretching into rehabilitation protocols has shown enhanced outcomes in pain reduction and functional improvement. Muscle Energy Techniques (MET), particularly Post Facilitation Stretching, utilize controlled muscle contractions to improve flexibility and relieve tension in shortened muscles. Proper application of MET targeting the LD has demonstrated effectiveness in increasing range of motion and supporting spinal stability in patients with chronic low back pain.

Inclusion Criteria:

• Patients had low back pain for more than 3 months Moderate disability (20 to 40 %) determined through Oswestry Disability Index Subjects with pain ranging 3 to 8 on NPRS Able to perform ROM of lumbar spine (flexion and extension) within range of pain Patient were not under any medical treatment (analgesics etc) both male and female

Exclusion Criteria:

• presence of any red flags (i.e tumor , metabolic disease, rheumatoid arthritis , osteoporosis , history of use of steroids ) SLR test positive Muscle weakness or paralysis of lower extremity Prior surgery of lumbar spine and pregnancy Any psychological problem