The association between high-fidelity knee kinematics during walking and patient-reported outcomes in patients with knee osteoarthritis.

INTRODUCTION

Determining whether knee joint kinematics amenable to wearable sensing associate with patient-reported outcomes in individuals with knee osteoarthritis (KOA) may inform modifiable targets for intervention and remote monitoring. This study examined whether high-fidelity knee joint angular kinematics (angle and angular velocity, acceleration, and jerk) as well as their step-to-step variabilities during walking associate with patient-reported outcomes in individuals with mild-to-moderate KOA.

METHODS

Sixteen individuals with KOA (age: 67.7 ± 7.9 yrs, preferred speed: 1.19 ± 0.18 m/s) completed standardized surveys and walked at three treadmill speeds: Slow (80% of preferred), Preferred (100%), and Fast (120%). Overground speeds established a standardized baseline to maintain relative intensity. Knee joint angles were computed via 3D motion capture and inverse kinematics and time derivatives yielded angular velocities, accelerations, and jerks.

RESULTS

Collectively, "less dynamic" walking knee joint kinematics at slower speeds (i.e., 80% of preferred) - defined using stride-average magnitudes and reduced step-to-step variability magnitudes, especially step-to-step variabilities in late stance - demonstrated exploratory associations with worse self-reported symptoms. Conversely, higher step-to-step knee joint kinematic variabilities associated with markers of kinesiophobia at preferred and faster walking speeds. These findings likely represent a conservative estimate of the associations between variability and function given the constrained nature of treadmill gait.

CONCLUSIONS

Given the kinematic nature of our outcome measures, our findings support the potential for wearable sensing to capture metrics of knee joint health, paving the way for scalable remote monitoring and better precision management of this degenerative disease.