Joint contributions to lower limb range of motion: A simple means of exploring joint function

This paper proposes a novel means of quantifying lower limb function by exploring relative contributions to lower limb range of motion (RoM LL ). Are joint contributions to RoM LL sensitive, and associated with gait velocity and joint kinetics and energetics? 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 RoM LL (RoM LL = sum hip, knee and ankle RoM). Sensitivity was assessed by comparing joint contributions to RoM LL 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 RoM LL and walking velocity, and joint contributions to RoM LL and total support moment, net power and total work during the propulsive phase of a drop jump. Patients displayed significantly ( p ≤ .023) smaller knee joint contributions to RoM LL 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 RoM LL and walking velocity. Significant ( p ≤ .004) correlations were reported between joint contribution to RoM LL and net power ( r rm =.804) and total work ( r rm =.868) during the propulsive phase of a drop jump. Relative joint contributions to RoM LL offer a sensitive and easy means of exploring lower limb function. • Joint contributions to lower limb RoM differ before total knee replacement. • Joint contributions to lower limb RoM differ after total knee replacement. • Joint contributions to lower limb RoM are independent of velocity when walking. • Joint contributions to lower limb RoM are associated with joint power in drop jumps. • Joint contributions to lower limb RoM are associated with joint work in drop jumps.