The effect of rocker sole shoes on ground reaction force in the elderly

Aging is associated with decreases in gait performance and mobility. Toe-only rocker sole is prescribed as a common shoe modification in restricted foot and ankle joints mobility. Therefore, this study aimed to determine the effect of toe-only rocker sole shoes on the ground reaction force (GRF) in the elderly. Twenty-one older adults walked on a walkway equipped with one force plate under six different conditions including barefoot (BF), normal shoe (NS), and four types of toe-only rocker sole shoes (RS) with various degrees of rocker angle (RS10, RS20, RS30, and RS40). The peaks of the GRFs in three planes were obtained. Different rocker angles could affect GRF parameters. The first peak of GRF (FZ(1)) significantly increased with both RS30 and RS40 compared to BF, NS, RS10, and RS20. FZ(1) significantly decreased with RS30 compared to RS40. The braking force (FX1) was significantly lower with NS compared to RS30 and RS40. FX1 was significantly higher with RS40 compared to the other shoe conditions. The propulsive force (FX2) significantly decreased during walking with BF compared to NS, RS20, RS30, and RS40. A higher FX2 was observed in RS40 than the other shoe conditions except RS30. Also, FX2 was significantly lower with RS10 compared to RS30. Increasing rocker angle may result in an increase in the peak magnitude of FZ(1), FX1, FX2 in the elderly without any improvement in walking speed.