Three-dimensional Motion Analysis of the Ankle during Backward Walking.

[Purpose] The purpose of this study was to perform kinematic and kinetic analyses of the ankle during both forward and backward walking using three-dimensional motion analysis. [Subjects] The subjects were 11 healthy adults. [Methods] Measurements of forward and backward walking motions were taken using a three-dimensional motion analysis device and 3 ground reaction force plates. The analysis segment was the standing phase and the items analyzed were walking time, maximum dorsal flexion of the ankle, maximum angle of plantar flexion, peak ankle power in the sagittal plane, workload of the ankle, and work rate. Statistical analysis consisted of comparisons using the t-test for each of the items measured during both forward and backward walking. [Results] The backward walking group had significantly lower ankle power, workload, and work rate. [Conclusion] The propulsive force in backward walking must come from some factor other than the ankle. The analysis of joint power is an important index for understanding the motion.