Kinematic comparison of split-belt and single-belt treadmill walking and the effects of accommodation.
BACKGROUND
Instrumented treadmills are becoming increasingly more common in gait laboratories. Instrumented side-split treadmills allow the collection of forces under each foot during walking. However, there may be a tendency to increase the base of support when walking on these treadmills, influencing other frontal plane mechanics as well. Therefore, the purpose of this study was to examine the effect of walking on a side-split instrumented treadmill on base of gait and frontal plane kinematics of the lower extremity.


METHODS
Twenty subjects walked on both a split and a single-belt treadmill. Base of gait and frontal plane kinematic angles and variability data were recorded. A one-way ANOVA was used to determine differences between the single and split-belt conditions at baseline and following a 10 min accommodation on the split-belt. The relationships between the change in base of gait and change in each kinematic variable were also determined.


RESULTS
On average, the base of gait was 3.7 cm wider on the split-belt treadmill with a 4mm gap between belts. No significant differences were observed in the mean values of lower extremity kinematics or kinematic variability at baseline or following the 10 min accommodation. However, the increase in base of gait was significantly related to a decrease in peak knee and hip adduction angles.


CONCLUSIONS
The 4mm gap between the treadmill belts significantly increased the mean base of gait in all subjects. This did not alter mean frontal plane kinematics. However, as base of gait increased, the tendency towards hip and knee abduction also increased.
Biomechanics and Movement Science Program, 301 McKinly Lab, University of Delaware, Newark, DE 19716, USA. aaltman@udel.edu
Allison R
AR
Altman
Darcy S
DS
Reisman
Jill S
JS
Higginson
Irene S
IS
Davis
D000054:Acceleration; D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena / Q000502:physiology*; D015331:Cohort Studies; D004867:Equipment Design; D005080:Exercise Test / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012680:Sensitivity and Specificity; D016138:Walking / Q000502:physiology*; D055815:Young Adult