Objective: To determine the effect of stretching and jogging on the series elastic muscle stiffness of the plantar flexors and on the range of dorsiflexion at the ankle joint.
Methods: 24 healthy subjects participated in this study. Each subject undertook all of the following protocols, in random order: (1) stretching protocol: five 30 s static stretches with 30 s rest between stretches; (2) aerobic jogging protocol: subjects ran on a treadmill for 10 min at 60% of their maximum age predicted heart rate; (3) combined protocol: subjects ran first and then stretched. A damped oscillation technique was used to measure the series elastic stiffness of the plantar flexors. Dorsiflexion of the ankle was assessed with a weights and pulley system that moved the ankle joint from a neutral position into dorsiflexion passively. Electromyography was used to monitor the activity of the plantar and dorsiflexors during these procedures. The statistical analysis of these data involved an analysis of covariance.
Results: For decreasing series elastic muscle stiffness running was more effective than stretching (P < 0.05). In contrast, the results for range of motion showed that the combination protocol and the stretching only protocol were more effective than the running only protocol (P < 0.05) for increasing dorsiflexion range of motion at the ankle.
Conclusions: Both jogging and static stretching exercises appear to be beneficial to individuals participating in sporting activities.