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Examining lower leg biomechanics during toe-in and toe-out walking in people with medial compartment knee osteoarthritis

University of British Columbia

Introduction: Knee osteoarthritis is a common and painful disease, and is one of the leading causes of disability in Canada. It is thought that one of the primary causes of disease progression is excessive knee joint loading. Thus, conservative treatments have aimed to reduce knee joint load, predominantly targeting the knee adduction moment – a valid proxy of tibial joint load distribution. Toe-in and toe-out walking are two such strategies which have proven effective in the short term at reducing the knee adduction moment, but still require longer-term assessment and a more thorough understanding of the ancillary effects at joints other than the knee prior to clinical implementation. The ankle joint in particular may be subjected to altered biomechanics during toe-in and toe-out walking. Purpose: The purpose of this thesis was to examine ankle biomechanics during toe-in and toe-out foot rotations in those with medial compartment knee osteoarthritis. Methods: Fifteen individuals with medial compartment knee osteoarthritis were recruited. In a single session, participants were instructed to walk in four conditions guided by real-time biofeedback of performance: 1) toe-in (+10°), 2) neutral (0°), 3) toe-out (-10°) and 4) toe-out (-20°). Ankle kinematics, kinetics and muscle activity were examined during over-ground walking. Results: Toe-out walking exhibited an increase (p=0.011) in peak ankle eversion compared to toe-in walking, while toe-in walking exhibited an increase in ankle inversion at heel strike (p<0.001) and frontal plane ankle angle excursion (p<0.01) compared to toe-out walking. No differences in ankle kinetics were observed. Toe-in walking exhibited a significant increase (p=0.03) in lateral gastrocnemius root mean square muscle activity compared to 20° toe-out. Lastly, toe-in walking was rated as most difficult and least preferred, while neutral walking was rated as least difficult and most preferred. Conclusions: Toe-in and toe-out walking are effective strategies for reducing knee joint load. However, altered ankle biomechanics may increase the risk of adverse events for some individuals. Longer-term studies are required to properly assess the relationship between lower extremity discomfort, ankle biomechanics and altered foot rotation in those with knee OA.

Text

2017-11-30

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/61750

Rehabilitation Sciences

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/