Joint Contributions to Lower Limb Range of Motion: A Simple Means of Exploring Joint Function

Background This paper proposes a novel means of quantifying lower limb function by exploring relative contributions to lower limb range of motion (RoMLL). Research Question: Are joint contributions to RoMLL sensitive, and associated with gait velocity and joint kinetics and energetics? Methods Sagittal plane hip, knee and ankle joint kinematics and kinetics, recorded using 3D motion capture, during walking and the propulsive phase of a drop vertical jump were used to calculate and explore relative joint contribution to RoMLL (RoMLL = sum hip, knee and ankle RoM). Sensitivity was assessed by comparing joint contributions to RoMLL between healthy controls and patients pre and 3-months post total knee replacement during walking. Correlation analysis was used to explore the association between joint contributions to RoMLL and walking velocity, and joint contributions to RoMLL and total support moment, net power and total work during the propulsive phase of a drop jump. Results Patients displayed significantly (p ≤.023) smaller knee joint contributions to RoMLL compared to healthy controls during walking pre and post total knee replacement (TKR). No significant correlations (rho ≤.143; p ≥.225) were reported between joint contributions to RoMLL and walking velocity. Significant (p ≤.004) correlations were reported between joint contribution to RoMLL and net power (r rm =.804) and total work (r rm =.868) during the propulsive phase of a drop jump. Significance: Relative joint contributions to RoMLL offer a sensitive and easy means of exploring lower limb function.