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 perforin stretching exercises on their own twice daily for 10,veeks. 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, 6.1degrees +/- 2.5degrees to 7.7degrees +/- 3.6degrees, P = .032) compared with no change in the control group. At comfortable walking speed. dynamic hip extension tended to increase in the treatment group (5.1degrees +/- 9.7degrees to 7.1degrees +/- 8.0degrees,, P = .103) compared with no real change in the control group (5.3degrees +/- 8.9degrees to 5.4degrees 7.5degrees, P = .928). Similarly. at fast walking speed, dynamic hip extension tended to increase in the treatment group (6.4degrees 9.8degrees to 8.4degrees +/- 8.0degrees, 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.