Comparison of angular lumbar spine and pelvis kinematics during treadmill and overground locomotion.

OBJECTIVE: To determine the differences between angular oscillation curves of the lumbar spine and pelvis during walkway and treadmill ambulation.
DESIGN: An in vivo observation of walking in overground and treadmill conditions.
BACKGROUND: Angular movements of the lumbar spine and pelvis have been obtained during overground and treadmill walking. No data are available to indicate whether lumbar spine treadmill findings may be compared or generalized to overground readings.
METHODS: Nine male subjects walked at their natural cadence along an 8 m walkway positioned over a motorized treadmill. During each of 20 walking trials, kinematic data of one full gait cycle were collected in the middle segment of the walkway. Following the overground readings the walkway was removed and treadmill recordings were taken at the subjects' preferred walking speed and at an imposed speed of 1.25 m/s. Movement patterns and maximum oscillation angles were calculated in each plane.
RESULTS: Cross-correlation values of pairwise comparisons demonstrated almost comparable movement patterns between walking conditions (r > or =0.891; p<0.001) except for the movement in the sagittal plane (r=0.642, p<0.01). ANOVA for repeated measures revealed significant (p<0.05) differences in the gait cycle duration as well as reductions in oscillation amplitudes of the upper lumbar region and the pelvis in both the frontal and transverse plane during treadmill walking compared to walkway locomotion.
CONCLUSIONS: Statistically significant differences exist for some angular lumbar spine movement parameters between walkway and treadmill locomotion. RELEVANCE: The observed differences between overground and treadmill locomotion should be taken in account when treadmill-based lumbar spine and pelvis kinematics want to be extended or compared to overground recordings.