تاثير چهار تكنيك مختلف كشش عضلاني بر انعطاف پذيري گروه عضلاني همسترينگ در دانشجويان پسر 18 تا 28 ساله دانشگاه علوم پزشكي زاهدان

The effect of four different muscle stretching techniques on flexibility of hamstring muscle group in 18-28 years old boy studentsʹ of Zahedan university of medical sciences

Background and Aim: Flexibility or extensibility of soft tissues that cross or surround joints, such as muscles, tendons, fascia, joint capsules, and skin is necessary for unrestricted movements during functional tasks. In order to increase flexibility, muscles should be stretched. There are different stretching methods that increase hamstring groupʹs flexibility. Only a few studies were carried out for determining the most effective one. This study aimed to determine the most effective stretching method to restore hamstring flexibility in lesser time in 18-28 years old boy students of Zahedan University of medical sciences in 2006. Materials and Methods: Sixty boy students ranging 18-28 years old were recruited for this clinical trial through simple non-probability sampling. Subjects were randomly assigned to 1 of 4 groups, 15 in each group, including (1) static stretching group, (2) hold-relax stretching group (HR), (3) stretching after post isometric relaxation (PIR), and (4) stretching based on reciprocal inhibition principle (RI). Stretching was carried out for six weeks, 5 times per week, and lasting 2 min on each occasion. Active and passive knee extension and passive hip flexion (degrees), distance between the tips of fingers in long sitting (cm), lumbopelvic rhythm mobility (cm) and lumbar lordosis (degrees) were measured using goniometer, tape measure, Modified Schoberʹs test, and flexible ruler, respectively. The obtained data was analyzed using one-way ANOVA and repeated measures. Results: Active knee extension was increased from 155.5 °±6.6° to 168.5ʹ±5.5" in static stretch group, from 158.5°±4.9* to 172.5 ±5.4° in HR group, from 156.75±6.8° to 169.7ʹ±5T in PIR group, from 157.1a±6.4° to 168.F±6.7* in RI group (P<0.0001). Passive knee extension was increased from 158.r±6.8° to 17l.8°±4.3 in static stretch group, from 160.6°±5.5° to 174.V±5.2° in HR group, from 158.3*±6.4° to 172°±5.6C in PIR group, from 159.4C±6.5° to 172.5*±5,8° in RI group (P0.05). Conclusion: The results showed that no specific method was found superior compared to others in improving hamstring flexibility.