Effect of stretching on ankle and knee angles and gastrocnemius activity during the stance phase of gait.

CONTEXT

Stretching exercises are commonly prescribed for patients and healthy individuals with limited extensibility of the gastrocnemius muscle.

OBJECTIVE

To determine effects of gastrocnemius stretching on ankle dorsiflexion, knee extension, and gastrocnemius muscle activity during gait.

DESIGN

Randomized-control trial.

SETTING

Biomechanical laboratory.

PARTICIPANTS

Sixteen volunteers (9 men and 7 women, mean age = 27 y) with less than 5 degrees of passive ankle-dorsiflexion range of motion randomly assigned to an experimental or control group.

INTERVENTION

The experimental group performed gastrocnemius stretching for 3 wk.

MAIN OUTCOME MEASURES

Maximum ankle dorsiflexion, maximum knee extension, and EMG amplitude of the gastrocnemius muscles were measured between heel strike and heel-off before and after intervention.

RESULTS

No significant effect of group or time was found on maximum ankle dorsiflexion, maximum knee extension, or EMG activity of the medial or lateral gastrocnemius muscles between heel strike and heel-off. The experimental group had significantly greater passive ankle-dorsiflexion range of motion bilaterally at posttest than the control group.

CONCLUSIONS

Stretching did not alter joint angles or gastrocnemius muscle activity in the early to midstance phase of gait.