Open access journal
Harmonic and polar screw invariants in single-case knee gait dynamics
By Wangdo Kim.
Abstract
Introduction
Knee stability during gait depends on coordinated interaction between segmental motion and environmental support. This study introduces a screw-theoretic framework for interpreting knee joint dynamics through harmonic and polar relations linking instantaneous screw axes (ISAs) and ground reaction forces (GRFs).
Materials and methods
A proof-of-concept reanalysis was conducted using a previously published Grand Challenge instrumented-knee dataset from one adult male participant with a reconstructed knee. ISAs of the thigh, shank, and knee were reconstructed during stance, and screw pitch and reciprocal organization were examined in relation to measured ground reaction and knee contact forces.
