Effect of Neural Mobilization as an Adjuvant to Static Stretching on Hamstring Flexibility: A Randomized Controlled Trial

Introduction:

Hamstring injury has always been most frustrating injury in sports. It is the commonest sports injury. It accounts for 10-30% of all sports injuries. Moreover, the risk of re-injury is even higher i.e. 12-31%. Also, the severity of recurrence is significantly higher than the initial injury. The incidence of injury and re-injury of hamstring in sports has not reduced in past three decades. All these findings suggest that prevention of hamstring injuries is absolutely important. Studies have shown that hamstring tightness causes the increased risk of hamstring injuryand also causes low back pain. Along with hamstring tightness, adverse neural tension is also a contributing factor of hamstring injury. Thus, along with stretching hamstring muscle for preventing its injury, addressing neural component is also equally essential, which could be the solution to recurrent hamstring injuries.

So, addressing the hamstring flexibility by targeting the nerve can be a good option to explore as this has not been looked at before. Static stretching being the most common intervention given for improving and maintaining hamstring length, we are providing the giving static stretching to all the three groups, out of which third group is an active control group. First group will receive mobilization technique (slider) while the second group will receive tensioner type of neural mobilization technique both of which are techniques described by Shacklock. Also, we are comparing the effect of the two types of neural mobilization techniques for their efficacy compared to themselves, along with checking if neural mobilization have any added benefit over static stretching in improving hamstring flexibility.

NEED FOR THE STUDY:

•       Added benefit of neural mobilization over static stretching in hamstring flexibility has not yet been studied.

•       Among the two types of neural mobilization techniques, which technique is better to improve hamstring flexibility is unexplored so far.

CLINICAL SIGNIFICANCE:

·         Neural mobilization if proved to be effective, will improve the hamstring flexibility in normal adults, and thus contribute in decreased incidence of hamstring injuries and low back pain.

·         Result will help clinician in decision making, whether or not to incorporate Neural mobilization techniques including sliders and tensioners in the flexibility exercises of hamstring.

·         If neural mobilization is found to improve hamstring flexibility, then adding neural mobilization to hamstring flexibility programme may be a major intervention in the improvement of hamstring flexibility and thus reduced hamstring injuries in sports and reduced over all incidence of low back pain.

OBJECTIVE OF THE STUDY:

·         To investigate if neural mobilization has any added benefit over static stretching in improving hamstring flexibility.

·         To compare the efficacy of the two types of neural mobilization techniques (Slider and Tensioner) in improving hamstring flexibility.

METHODOLOGY:

Single-blinded Randomised Controlled Trial will be done on normal healthy individuals with limited hamstring flexibility in Manipal University, Karnataka. Knee extension angle will be used as the primary outcome measure which will be measured by blinded assessor by using two inclinometers.

60 volunteer participants will be randomly divided into three groups using computer generated random number.

Three groups are:

1. Static stretching + Slider technique

2. Static stretching + Tensioner technique

3. Static stretching only (control group)

Intervention will be given for total of three days of week ie first, fourth and seventh day. In between the follow up time of one week, all participants will perform static stretching as the home exercise. Data will be analysed using appropriate statistical measures.