The effect of voluntary toe-walking on body propulsion.

OBJECTIVE: We studied the kinetics of toe-walking by comparing the linear power flow from the leg to the upper-body. Our hypothesis was that toe-walking has no inherent biomechanical disadvantage with regard to upper-body propulsion and support.

DESIGN: We studied healthy subjects capable of both heel-toe gait and voluntary toe-walking so that the two forms of gait could be directly compared.

BACKGROUND: Ankle joint power at terminal stance is significantly reduced in toe-walking, which has been presumed to imply impaired propulsion and support. However, linear power analysis may be more appropriate for assessing this aspect of gait.

METHODS: We compared the normal heel-toe gait of 10 healthy young adult subjects to their voluntary toe-walking gait using gait laboratory kinematic and kinetic data. Inverse dynamic analysis was performed to determine the net joint moments and joint linear powers. The contribution of each joint moment to the total hip linear power was also determined.

RESULTS: Hip linear power for toe-walking was similar to that of heel-toe gait with no significant differences in the linear power peaks. The stance phase contributions of the knee and ankle moments were significantly altered in toe-walking only in early stance.

CONCLUSIONS: Toe-walking does not inherently impair propulsion and support.

RELEVANCE: Linear power analysis is a useful adjunct to clinical gait analysis, complementing joint power analysis. Understanding the inherent kinetics of toe-walking will enhance our analysis of pathological toe-walking and improve treatment design.