The Effects of Four Different Muscle Stretching Techniques on Flexibility of Hamstring Muscle Group and Active and Passive Knee Extension in Elite Soccer Player

The aim of the present study was to determine the most effective stretching method to restore hamstring flexibility in a minimum period in male soccer player. Forty four soccer players (age range: 20-29 years) were selected by simple non-probability sampling. Subjects were randomly assigned to four groups, (11 members each group): (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, 6 sessions per week, and 2 minutes each session. Active and passive knee extension and passive hip flexion (degrees) were measured by a goniometer. The obtained data were analyzed by one-way ANOVA and repeated measures. Active knee extension increased from 155.1?2.5 to 170.9?3.4 in static stretch group, from 157.5? 4.5 to 174.9 ? 2.9 in HR group, from 155.2 ? 4.5 to 171 ? 2.9 in PIR group, from 156.4 ? 2.5 to 170.6 ? 3.9 in RI group (P<0.0001). Passive knee extension increased from 157.9 ? 5.2 to 173.8 ? 4.9 in static stretch group, from 160.9 ? 3.2 to 176.3 ? 4.1 in HR group, from 157.9 ? 1.2 to 173.9 ? 3.2 in PIR group, from 157.6 ? 5.1 to 173.5 ? 4.2 in RI group (P<0.0001). Passive hip flexion increased from 64.8 ? 4.3 to 77.4 ? 6.3 in static stretch group, from 65.8? 3.3 to 80.5 ? 1.1 in HR group, from 67.1 ? 2.9 to 79.5 ? 5.2 in PIR group, from 66.8 ? 3.2 to 78.3 ? 4.6 in RI group (P<0.0001). The results showed that no specific method which improves hamstring flexibility in soccer players was superior to others.