Do orthotic walkers affect knee and hip function during gait?

Abstract

Study Design: A repeated measures cross over study.

Background: The majority of previous studies on the use of orthotic walkers have been focussed on their ability to off load the structures in the foot and ankle, however little is known about their effects on hip and knee mechanics.

Objectives: The objective of this study was to determine the effects of two designs orthotic walker on the knee and hip joints compared to normal footwear.

Methods: Ten subjects with no history of lower limb problems walked under three randomised conditions; Össur Rebound, Aircast FP and normal footwear. Kinematic and kinetic data were collected using a ten camera Qualisys motion analysis system and four AMTI force plates and analysed using the Calibrated Anatomical System Technique.

Results: Significant differences in hip kinematics between both walkers and normal footwear and in knee kinematics between the Össur Rebound and normal footwear. Significant differences were also seen in the knee moments between both walkers and normal footwear.

Conclusion: Both walkers show significant differences compared with normal footwear, however the Össur Rebound appears to produce the greatest deviation which includes a greater hyperextension moment at the knee which could be damaging over long term usage.

Clinical Relevance: Further research is needed into the effects of orthotic walkers on the knee and hip joint mechanics, which should help to inform future designs of walker, with a greater focus on obtaining a more normal gait pattern.