Effects of active feedback gait retraining to produce a medial weight transfer at the foot in subjects with symptomatic medial knee osteoarthritis

Abstract

This study aimed to determine if active feedback gait retraining to produce a medial weight transfer at the foot significantly reduces the knee adduction moment in subjects with medial compartment knee osteoarthritis. Secondarily, changes in peak knee flexion moment, frontal plane knee and ankle kinematics, and center of pressure were investigated. Ten individuals with medial compartment knee osteoarthritis (9 males; age: 65.3 ± 9.8 years; BMI: 27.8 ± 3.0 kg/m2 ) were tested at self-selected normal and fast speeds in two conditions: Intervention, with an active feedback device attached to the shoe of their more affected leg, and control, with the device de-activated. Kinematics and kinetics were assessed using a motion capture system and force plate. The first peak, second peak, and impulse of the knee adduction moment were significantly reduced by 6.0%, 13.9%, and 9.2%, respectively, at normal speed, with reductions of 10.7% and 8.6% in first peak and impulse at fast speed, respectively, with the active feedback system, with no significant effect on the peak knee flexion moment. Significant reductions in peak varus knee angle and medialized center of pressure in the first half of stance were observed, with reductions in peak varus knee angle associated with reductions in the knee adduction moment. This study demonstrated that active feedback to produce a medial weight-bearing shift at the foot reduces the peaks and impulse of the knee adduction moment in patients with medial compartment knee osteoarthritis. Future research should determine the long-term effect of the active feedback intervention on joint loading, pain, and function. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2251-2259, 2017.

Keywords: active feedback; gait modification; knee; knee adduction moment; osteoarthritis.

Conflict of interest statement

Conflict of Interest Statement: The authors declare no conflict of interest that could influence the content of the presented work.

© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Figures

Figure 1

The active feedback gait modification intervention, incorporating a force sensor placed under the lateral side of the heel, a vibration motor placed in contact with the skin on the foot/ankle, and a light indicator to indicate activation of the vibration motor.

Figure 2

Average KAM curves of control gait (solid line) and of medial weight transfer gait (dashed line) during stance phase at (A) normal and (B) fast speeds.

Figure 3

Individual subject percent changes (ordered from largest to smallest) in the first peak KAM (A and D), second peak KAM (B and E), and KAM impulse (C and F) at normal (top row) and fast (bottom row) speeds with active feedback gait retraining versus control.

Figure 4

Associations between individual subject changes (intervention – control) in the first peak KAM (A and C) and second peak KAM (B and D) and changes in peak varus knee angle during loading at normal (top row) and fast (bottom row) speeds with active feedback gait retraining versus control. Reductions in first peak KAM, second peak KAM, and peak varus knee angle with active feedback are shown as negative values.