MUD Mired in time...

Stepping video frames through this girl’s knee flexion curve showed that there was no significant knee flexion (Hip-to-ankle shortening during verticality of stance). Flexion seen above was mostly for cramp relief. It is totally absent in forward progression. Remember? Blood flow during active contraction is poor? Can’t recharge. Cramps. To get technical, knee angle, as such, has magnitude but not direction. The HARP line which is another way to measure knee angle & additionally has magnitude & direction. It is also linked to stature. HARP uses the same positions of hip, knee & ankle in space as does knee angle. It tells you both WHAT and the WHY at the same time. So, swing seems suspicious. And knee flexion comes from what? Knee flexors? In normal gait, knee flexors are not used to bend the knee. What does? Hip flexors, center of mass inertia to rise against gravity, planted foot ankle resistance, heel descent, effective foot length to forward roll over and maybe things worn while walking… Eccentric gait is normal gait. Key to rehabilitation is the WOBBLE ZONE often, unfortunately, smudged away when graphs are smoothed.