The frequency of hamstring stretches required to maintain knee extension range of motion following an initial six-week stretching programme

Abstract

Stretching exercises are commonly prescribed in training and rehabilitation programmes. The purpose of this study was to determine the frequency of on-going hamstring stretching required to maintain knee extension range of motion (ROM) following an initial stretching programme. A test-retest randomised control trial was undertaken. Sixty-three healthy male participants were randomly assigned to two stretch groups and a control group. Active knee extension (AKE) stretches were performed five days a week for an initial six weeks. Stretch group 1 then reduced the frequency of stretching to three days per week, and stretch group 2, to one day per week, for a further six weeks. The control group did not stretch. Active knee extension ROM was measured at baseline, weeks six and 12. A significant improvement in AKE ROM was observed in stretch group 1 (17.5° SD 11.8°) and 2 (18.8° SD 7.1°) after the initial six weeks of stretching (p < 0.05). After six-weeks of on-going stretching group 1 maintained their improvement in ROM, whereas stretch group 2 lost ROM. The difference between stretching groups was significant (p < 0.05) and no change in ROM was observed in the control group. These results indicate that an on-going hamstring stretching programme with a frequency of three times a week is required to maintain the initial improvement in ROM.