7.2 METHOD OF COLLECTION OF DATA:
(A) SAMPLING TECHNIQUES:
• Convenient random sampling.
(B) TOOLS:
• Goniometer (for measuring ROM).
• Active knee extension test (for measuring hamstring tightness).
(C) METHODOLOGY:
(I) STUDY DESIGN:
Randomized experimental study.
(II) INCLUSION CRITERIA:
In order to participate in this study, subjects will have to fulfill following criteria:
• AGE: 16-20 years
• Male
• Tight hamstring muscles (the inability to achieve greater than 160 degrees of knee extension with the hip at 90 degree of flexion)46,47
• Healthy subjects who are not indulged in any sports activity or any kind of physical exercise program will be recruited.
• No history of endocrine or thermoregulatory disorders, arthritic conditions, or musculoskeletal injuries.
(III) EXCLUSION CRITERIA:22
• Below 16 and above 20 years of age.
• Previous lower back or hamstring injury.
• A bony block limiting joint motion.
• Metal pins, plates or screws in the pelvis/ femur/ tibia/ fibula.
• A recent fracture, and bony union is incomplete.
• Evidence of an acute inflammatory or infectious process (heat and swelling).
• Sharp, acute pain with joint movement or muscle elongation.
• A hematoma or other indication of tissue trauma is observed.
• Hypermobility already exists.
• Subjects with an athletic profile.
(IV) PROCEDURE:
Subjects who fulfill the selection criteria will be included in the study. They will be taken in to the research once they sign the informed consent.
A total of 30 subjects will be selected and divided into 2 groups of 15 subjects each by simple randomization. Group 1 will be given manual passive stretching followed by cold application and Group 2 will be given modified PNF stretching followed by cold application. Choice of which lower extremity to use for the stretching protocols would be determined by the toss of a coin for each subject; heads represent right lower extremity, tails represent left lower extremity. Pre-test and post-test data for active ROM will be collected before and after intervention.
The study will be carried out in three stages-
a) Pre- intervention measurement
b) Intervention
c) Post-intervention measurement.
(a) Pre-intervention measurement
Measurement of supine active knee extension as described by Gajdosik et al48 as an indicator of hamstring flexibility will be used in both the groups. Subjects would be asked to wear shorts to allow easy access to bony landmarks. Subjects would then be instructed to assume a supine position, with the hip and knee flexed at 90 degree, verified with goniometric measurements. Each subject’s pelvis would be secured to the table with a strap over the anterior superior iliac spines. Another strap would be placed over the mid -thigh of the contralateral limb to secure it to the table. While maintaining 90º of hip flexion, subjects would be asked to actively extend the knee as far as possible. Once they could no longer extend the knee, or the hip began to lose the 90º angle as determined by the investigator, the angle of knee flexion would be then obtained by investigator.
(b) Intervention
The testing would be occurring over a 1 week period, with each subject in groups 1 and 2 receiving respective interventions one time a day. The subjects would be tested at approximately same time each day. During this period, the subjects will be asked to refrain from any kind of sports activity or exercise. Pre- test measurement will be taken on 1st day and intervention will be carried out for 5 days in the week with post-test measurement taken on 5th day. 6th day will be a resting day and on the 7th day measurement will be taken to check maintenance of gained ROM.
Group 1: Manual passive stretching followed by cold application
The subject will be lying supine. With the subject’s knee fully extended, the lower leg of the subject will be supported with the therapist’s shoulder, and the opposite extremity along the anterior aspect of the thigh will be stabilized with the other hand of the therapist. Now, hip will be flexed as far as possible.22 The stretched position will be held for 30 seconds. Sequence will be repeated 4 times.49 At the end of 4th repetition, cold pack will be applied over the hamstrings (posterior aspect of thigh) for 10 minutes with the subject in prone position. Bags filled with crushed ice will be used as cold pack.6
Group 2: Modified PNF stretching (HR-AC) followed by cold application
The subject will be lying supine. The technique will be performed without hip rotation. The investigator will passively stretch the hamstrings until the subject feels mild stretch, then ask the patient to isometrically contract the hamstrings by attempting to push his leg back against the resistance of the investigator for 10 seconds. Then the subject will be let to relax for 5 seconds. Then the subject will perform a concentric contraction of the agonist (quadriceps) by doing active knee extension. The subject will actively move the extremity through the increased range.22,50 This procedure will be repeated 4 times. At the end of 4th repetition, cold pack (bags filled with crushed ice) will be applied over the hamstrings for 10 minutes with the subject in prone position.6
(c) Post- intervention measurement
Post-stretch measurement will be performed in the same manner as the pre-stretch measurement, i.e; by using active knee extension test, and data collected by the same therapist at the end of intervention on the 5th day. 6th day will be a resting day for the subjects and on the 7th day measurement will be taken to check the maintenance of gained ROM.