The aim of this research is to find and compare the effect of Bowen's technique and Muscle energy technique on intensity of pain, active knee extension, limited forward bending and active straight leg raise on hamstrings tightness in patients with chronic non-specific low back pain. A randomized control trial is conducting at Railway General Hospital, Rawalpindi and Al-Ain Hospital, Wah Cantt. The sample size is calculated through open epi is 24. The subjects are divided in two groups, 12 subjects in Bowen's technique group and 12 in Muscle energy technique group. Study duration is of 6 months. Sampling technique applied is non-probability convenient sampling for recruitment and group randomization using sealed envelope method. Only 18-35 years individuals of hamstrings tightness with chronic non-specific low back pain are included. Tools used in the study are Numeric pain rating scale (NPRS), Active knee extension, Sit and reach test, Active straight leg raise and Goniometer. Data will be analyzed through SPSS 21.

Hamstring muscles are well known for their immense tendency to tightness which is due to their multi-joint function, their tonic postural character, and considerable amount of tensional forces to which they are constantly submitted. The ability of the muscle to lengthen allowing one joint (or more than one joint) to move through the range of motion is due to the flexibility of the muscle. If a muscle has good flexibility it will allow muscle tissue to accommodate to imposed stress more easily and allows efficient and effective movement and will assist in preventing or minimizing injuries and enhance performance of the muscle.

The length of the hamstring muscles is considered to play an essential role in both the effectiveness and efficiency of fundamental human movements such as walking and running. Particularly in the field of rehabilitation, flexibility of the muscle is important in postural balance, complete maintenance of the range of motion of knees and hips, injury prevention and optimization of musculoskeletal function. Tight hamstrings have been involved in lumbar spine dysfunction and shows strong positive correlation between low back pain and reduced hamstring flexibility. Hamstring muscle tightness leads to decreased range of motion of lumber flexion and pelvic tilt. This can alter the biomechanics of lumbar spine and may lead to back pain. Mainly hamstrings flexibility may prevent acute and chronic musculoskeletal injuries, low backache problems, postural deviations, gait limitations and chances of fall.

Low back pain (LBP) is described as the pain located in the lower part of the spine (lumbo-sacral region), coming from this area and optionally radiating to one or both lower limbs. It occurs in a great amount of the population, in about 80% of people and it has a different intensity. Non-specific LBP (low back pain) is defined as low back pain not attributable to a known cause there is no pathology within the spine such as cancer, osteoporosis, trauma or fracture. It represents 90-95% of the cases of Low back pain. There are several factors which are responsible for development of Low back pain. Various factors include increased lumber lordosis, reduced abdominal muscle strength, and decreased back extensor muscle endurance, back extensor muscle flexibility, length of iliopsoas and hamstring muscle flexibility.

Muscle energy technique (MET) is a manual technique developed by osteopaths that is now used in much different manual therapy professions. It is gentle manual therapy technique for restricted motion of the spine and extremities and is an active technique where the patient, not the clinician, controls the corrective force.

One of the two techniques is 'Post-isometric relaxation technique (PIRT)' which uses controlled, voluntary isometric contractions up to 20% of a target muscle group. MET is claimed to be useful for lengthening a shortened muscle, improving range of motion at a joint and increasing drainage of fluid from peripheral regions. This approach which targets primarily the soft tissue is also known as 'active muscular relaxation'.

Bowen's technique (BT) was developed by Thomas Bowen in the 1950s in Geelong, Australia which is a dynamic system of muscle and connective tissue therapy. Bowen's Technique is a technique, based on a delicate movement and a series of manipulation of soft tissues. It is a soft tissue therapy, in which therapist uses fingers or thumb to apply gentle rolling moves over muscles, tendons, and other connective tissues in specific parts of the body. Minimum of 2 minutes will be allowed between moves to allow the body to respond and then the whole procedure will be repeated again. Sequence of receiving bilateral moves are applied over segments of erector spinae ,latissimus dorsi, gluteals,the hamstrings muscles proximally and distally, Tenser fascia latae, hip adductors are many more. A classic Bowen's technique session usually lasts from 15 to 45 minutes.

In general, the mechanism of action of Bowen's Technique is based mainly on the concept of proprioception. The skin is innervated tissue and has various types of receptors that detect changes during the position of touch, pressure, vibration, temperature or pain. The fascia also plays the role of a system for collecting, transmitting and processing information. There is even less data on the physiological effects of Bowen's Therapy. There are largely unsubstantiated claims that it acts through effects on fascia, muscle, and cutaneous sensory receptors that give rise to a rebalancing of autonomic nervous system (ANS) activity, muscle relaxation, altered myofibroblast activity, and changes in the type of collagen. Adipocytes and fibroblasts, on the other hand, are responsible for mechano-transduction and lead to a wide range of sensory sensations and communication signals. Therefore, it has been suggested that the contact of the therapist's hands with the patient's skin initiates communication with structures lying deeper. Bowen's studies provide implications of fascially induced following stimulation of mechanoreceptors. The effect of rolling moves that are characteristic of this method is muscular and fascial loosening.

There have been many studies done to check the effectiveness of stretching techniques to increase the flexibility of Hamstrings amongst the most common is MET. Bowen's technique is a specific form of therapy and the concept of treatment of patient according to Bowen's is significantly different from the commonly known methods. There are no studies done pertaining to the comparison of MET and Bowen's Technique for hamstrings flexibility in patients with non-specific low back pain and hence the need of the study arises to check for the more superior form of technique in the treatment of hamstrings flexibility. Until now, the effects of Bowen's Technique therapy have been most often described in the form of a case study. It is difficult to find research conclusions from such works only.

A research was conducted in 2020 entitled as "The effect of muscle energy technique on flexibility of hamstring muscle in Futsal Players" and concluded that Muscle energy technique increased flexibility of hamstrings among futsal players by improving ranges of knee extension. This study also shows the implacability of Muscle Energy Technique in a clinical setting, where it can be performed as a treatment technique for patients who come in for physiotherapy relating to reduced hamstring flexibility.

A research was conducted in 2018 entitled as "Bowen Technique for patients with low back pain" concluded that there were clearly noticeable results in the severity of pain, the range of motion and the degree of disability of respondents referring Oswestry standardized scale. It can be concluded that subsequent treatments would still eliminate pain and improve the health of patients as well.

A research was conducted in 2017 entitled as "Effect of Bowen Technique versus Muscle Energy Technique on Asymptomatic Subjects with Hamstring Tightness" concluded that 3 sessions on alternate days for a week proved to be effective in improving popliteal angle and sit and reach test for flexibility measurements in both Bowen technique as well as muscle energy technique but Bowen technique has shown more improvement in hamstring flexibility and ROM than muscle energy technique.

A research was conducted in 2013 entitled as "Comparative study between the effectiveness of Bowen technique and dynamic soft tissue mobilization in increasing hamstrings flexibility" concluded that there was a significant improvement following the application of Bowen Technique than compared to Dynamic Soft Tissue Mobilization in improving flexibility of hamstring muscle as determined by Active Extension Test.

Inclusion Criteria:

• 20-50 degrees active knee extension loss with hip in 90 degree flexion.
• Low back pain from more than 3 months.
• Minimum of 30° restriction in straight leg raise (SLR).
• Currently seeking treatment for low back pain.
• Low back pain radiating above knee.
• Subjects willing to participate in the study.

Exclusion Criteria:

• Fractures of hip and knee.
• SLR greater than 100 degrees.
• Nerve lesion of lower limb.
• Taking medications which may interfere with the results of this study including muscle relaxants.
• Major surgery scheduled during treatment or follow-up period.
• Suspected or confirmed spinal pathology (e.g., tumor, infection, fracture, inflammatory disease).