Gait Modification to Reduce Peak Knee Abduction Moment

Abstract

This dissertation evaluates the effects of various gait modification interventions on first peak knee abduction moment (KAM). As KAM is a commonly used surrogate measure for medial compartment knee osteoarthritis (KOA) severity and progression, the results of this dissertation may be used to provide evidence for the efficacy of gait modification as a clinical treatment for the disease. The contents of this dissertation covers four major areas: (1) The background and theoretical framework behind gait modification to reduce KAM and treat KOA, (2) A comparison of the acute effects of three gait modifications on KAM in healthy adults, (3) The feasibility of a wearable haptic biofeedback system to train gait modification outside of the laboratory environment, (4) A pilot study for a randomized-controlled trial investigating the effects of long-term gait modification intervention designed to reduce KAM in KOA patients. The results of the studies included in this dissertation have several implications for the future of this research area. The first study supports evidence from prior investigations that no one gait modification is most effective to reduce KAM for all individuals. The wide range in individual response to both type and magnitude of gait modification on KAM suggests that future interventions should screen individuals for which modification is most appropriate. When an appropriate gait modification is found, the next concern is how to best train individuals in its adoption. Most studies have used complex systems (such as 3D motion capture software) to provide training feedback, which are only available in research settings. The results of the second study suggest that these feedback systems can be replaced by wearable inertial measurement units (IMU) which are advantageous in their portability and simplicity. Although more development is needed, there is potential for IMU systems to be worn outside of the laboratory environment while being controlled by patients through a smartphone application, allowing them to receive feedback based on gait during their activities of daily living. Lastly, as most prior literature on the topic has used quasi-experimental designs there is a pressing need for both gait modifications and feedback methods to be tested in the target population using study designs that provide the highest level of evidence. Preliminary results from a randomized-controlled trial (RCT) that employs both individual patient screening of gait modification response and use of a wearable real-time haptic biofeedback (RTB) system provide evidence that KAM reductions seen in healthy participants are replicable in KOA patients.