How does altering the foot progression angle affect lower limb kinetics, spatiotemporal and kinematic gait parameters when using a haptic feedback system?

Abstract

Knee osteoarthritis is a common joint disease, affecting the knee joint. To help slow down the degeneration of cartilage, changing people's gait is a known solution. The most common modification is teaching people to walk toeing-in or toeing-out, changing their foot progression angle (FPA). However, it is still unclear what the effect is of changing the FPA on other gait parameters and lower joint kinetics. Changing the FPA, also changes gait parameters such as gait speed, step width, stride length, trunk lean, and medial thrust. It is hypothesized that lower joint kinetics are negatively affected when altering the FPA. This thesis focuses on the effect on the lower joint kinetics and on the gait parameters when changing the FPA.

Tests are done on healthy subjects with four FPA alterations besides normal gait, a small and large angle toeing-in and toeing-out. A haptic feedback device is used that contains vibrating motors located at the medial and lateral side of the calf to teach participants to walk in the desired angle. First participants are asked about the ease of use and comfort of the haptic feedback system. Second, the knee adduction moment (KAM) and knee flexion moment (KFM) are measured for each participant to evaluate the effect of the different FPA's. Third, the moments in the lower joints, hip and ankle, are measured to research the effect of different FPA's on the loading within these joints. This load is measured at peak value and as area under the graph. Lastly, there is researched what gait parameters participants alter when changing the FPA. The thesis mainly focuses on the effect on the lower joint kinetics since literature still shows a gap here.

The haptic feedback resulted comfortable for most participants, the ease to achieve a high amount of correct steps within the asked FPA appeared more difficult. Changing the FPA to reduce the KAM, showed for the participants different angles that maximally reduces the KAM. Highlighting the importance of a personalized approach. The hip adduction moment and ankle moment both increase overall for the participants. While the hip rotation and flexion moment show a mean reduction. Making it important to focus most on the hip adduction moment and ankle moment, and how to lower these increases in moment. Otherwise this could result in hip osteoarthritis. Different FPA's also change the impact of the gait parameters for the participants. Indicating participants to change their entire posture when adapting different angles. Resulting more aspects to focus on when learning participants to walk differently.

To conclude, changes in the FPA have effect on the KAM, gait parameters, and on the lower joint kinetics. The reduction on KAM differs per participant, indicating a personalized approach. Gait parameters change when applying FPA's, mainly gait speed, stride length and step width change for most participants. Measurements on the lower joint kinetics show interesting insights on the effect of changing the FPA. Highlighting the hip adduction moment and ankle moment to focus on to prevent possible excessive load and damage.