Comparing Effects of Six-week Active and Passive Static Stretching on Lumbar-Pelvic Rhythm In Males With Hamstring Shortness

Forward bending is a coupled movement combining lumbar flexion and pelvic rotation, the so-called lumbar–pelvic rhythm. Clinical observations have suggested that hamstring tightness influences the lumbar pelvic rhythm and may be associated with modifications in the sagittal spine curvatures during trunk flexion. Moreover, there is still no agreement on the best stretching techniques. Therefore, the aim of the present study was to compare the effect of six weeks of active and inactive static training on lumbar-pelvic rhythm in forward flexion in men with hamstring shortness.

This study was a quasi-experimental study with pretest/posttest with two groups. In this study, 26 men with hamstring shortness, with a Mean±SD age of 25.76±1.71 years were selected (via purposeful sampling). Hamstring muscle shortness was measured utilizing the SLR and 90-90SLR tests. Measurements of the lumbar pelvic rhythm were recorded in the three-phase forward bending by a spinal mouse. Variables included pelvic rotation and lumbar flexion. Active and passive static stretching were respectively jack-knife and kneeling hamstring stretching techniques. To compare pretest and posttest values of active and passive static stretching groups, the paired t-test and Wilcoxon test were utilized. Furthermore, to assess the difference between active and passive static stretching groups, the ANCOVA and Mann-Whitney U test were utilized.

After six weeks of active and passive static stretching, the total pelvic rotation significantly increased in contrast to total lumbar flexion (P<0/05). A comparison of pelvic and lumbar ROM output did not reveal a significant difference between active and passive static groups (P>0/05).

Compliant with the findings, active and passive static stretching could change the lumbopelvic rhythm to a pelvic-dominant motion, indicating that a flexible hamstring is important for preventing low back pain and other problems associated with the disturbance of the lumbo-lumbar rhythm.