Effect of a hip flexor-stretching program on gait in the elderly.

OBJECTIVES

To test whether a reduction in peak hip extension during the terminal stance phase of walking in elderly compared with young adult subjects represents a hip flexor contracture impairment rather than some dynamic consequence and to test the hypothesis that stretching the hip flexors improves both static and dynamic peak hip extension, as well as other age-related gait changes about the ankle.

DESIGN

A double-blinded, randomized, controlled trial.

SETTING

Stretching exercises were performed in the subjects' homes. Pre- and postassessments were performed in a gait laboratory.

PARTICIPANTS

Ninety-six healthy elderly individuals in 2 groups: treatment (n=47) and control (n=49).

INTERVENTION

The treatment group received a 1-time instruction in hip flexor stretching, whereas the control group received a 1-time instruction in shoulder abductor stretching. Participants in each group were asked to perform stretching exercises on their own twice daily for 10 weeks.

MAIN OUTCOME MEASURES

Static and dynamic peak hip extension, peak anterior pelvic tilt, and other peak kinematic and kinetic variables during the gait cycle.

RESULTS

There was a modest improvement in static peak hip extension as measured by a goniometer within the treatment group (mean +/- standard deviation, 6.1 degrees +/-2.5 degrees to 7.7 degrees +/-3.6 degrees, P=.032) compared with no change in the control group. At comfortable walking speed, dynamic hip extension tended to increase in the treatment group (5.1 degrees +/-9.7 degrees to 7.1 degrees +/-8.0 degrees, P=.103) compared with no real change in the control group (5.3 degrees +/-8.9 degrees to 5.4 degrees +/-7.5 degrees, P=.928). Similarly, at fast walking speed, dynamic hip extension tended to increase in the treatment group (6.4 degrees +/-9.8 degrees to 8.4 degrees +/-8.0 degrees, P=.093) compared with no change in the control group. Changes in ankle kinematics and kinetics included a significant improvement in peak ankle plantarflexion and a tendency to improved ankle power generation.

CONCLUSION

The static and dynamic trends to improvement in peak hip extension were of similar magnitude, suggesting that age-related reduction in peak hip extension during gait is the result of a static hip flexion contracture rather than a dynamic consequence. Additionally, age-related changes in ankle kinematics and kinetics may be secondarily related to hip flexion contracture impairment rather than impairment at the ankle per se. This study was limited by the exercises being unsupervised and relying on 1-time instruction. A more rigorous and supervised hip flexor-stretching exercise program may yield more substantial improvements in gait parameters.