Lower limb joint kinetics in walking: the role of industry recommended footwear.

The effects of current athletic footwear on lower extremity biomechanics are unknown. The aim of this study was to examine the changes, if any, that occur in peak lower extremity net joint moments while walking in industry recommended athletic footwear. Sixty-eight healthy young adults underwent kinetic evaluation of lower extremity extrinsic joint moments while walking barefoot and while walking in current standard athletic footwear matched to the foot mechanics of each subject while controlling for speed. A secondary analysis was performed comparing peak knee joint extrinsic moments during barefoot walking to those while walking in three different standard footwear types: stability, motion control, and cushion. 3-D motion capture data were collected in synchrony with ground reaction force data collected from an instrumented treadmill. The shod condition was associated with a 9.7% increase in the first peak knee varus moment, and increases in the hip flexion and extension moments. These increases may be largely related to a 6.5% increase in stride length with shoes associated with increases in the ground reaction forces in all three axes. The changes from barefoot walking observed in the peak knee joint moments were similar when subjects walked in all three footwear types. It is unclear to what extent these increased joint moments may be clinically relevant, or potentially adverse. Nonetheless, these differences should be considered in the recommendation as well as the design of footwear in the future.