Objective: To test the hypothesis that reduced hip extension and increased anterior pelvic tilt in the elderly are dynamic gait phenomena that do not occur during normal standing posture.
Design: Experimental.
Setting: Gait laboratory.
Participants: Twenty-five older adult subjects (mean age +/- standard deviation, 71+/-5 y) and 25 young adult subjects (mean age, 26+/-5 y).
Intervention: Subjects were observed during standing and walking at self-determined comfortable, slow, and fast walking speeds. Positions and kinematics of the pelvis and lower extremities were measured using a 3-dimensional video-based motion analysis system.
Main outcome measures: Peak hip extension and anterior pelvic tilt.
Results: There were no statistically significant differences between the older and young adult groups during standing with respect to either hip extension (3 degrees +/-5 degrees vs 1 degrees +/-6 degrees) or anterior pelvic tilt (11 degrees +/-5 degrees vs 10 degrees +/-5 degrees). On the other hand, at comfortable walking speeds, the older adult group had reduced peak hip extension (7 degrees +/-6 degrees vs 11 degrees +/-6 degrees , P<.05) and increased anterior pelvic tilt (15 degrees +/-5 degrees vs 11 degrees +/-5 degrees) compared with the young adult group. At fast walking speeds, peak hip extension was significantly reduced in the older adult group than in the young adult group (9 degrees +/-6 degrees vs 14 degrees +/-6 degrees , P<.05), but there was no significant difference at slow walking speeds (6 degrees +/-6 degrees vs 9 degrees +/-5 degrees ).
Conclusions: Age-related changes in gait defined by reduced peak hip extension and increased pelvic tilt are dynamic rather than standing postural characteristics.