MUD Mired in time...

Notice (medial rotation crouch gait) & that the knee angle is unchanged in the three frames indicating early stance to midstance to preswing. This girl is a super athlete. Why is she spontaneously doing this? … and toe walking ? We can restate this a little differently for clarity… These mechanisms can be approximated using 'harmonics proportioned in a Fibonacci series starting with a stature matching 'power' (wheel radius = ½ stature). It is tempting to assume these proportions as the bone sizes. It kind of works. Interestingly, these harmonics tickle the edge of being in a Fibonacci series. Forcing Fibonacci harmonics into a Fourier-like summation series comes close. Close, but no prize. Our muscle bulk is more proximal with tendons reaching to the target limb insertions. In this way the pendulum periods are NOT quite those of the bone lengths but more like a metronome . The period is derived from lengths between a moving joint center to the segment’s center of mass but power or distance uses the full radius length. For this reason, harmonic size (‘power’) and speed of rotation (‘period’) are somewhat disconnected. We'll call it skewed. This gains more distance without being slowed by it as would happen with a longer pendulum. This is why speed runners flex so severely … to shorten the forward leg’s pendulum inertia which allows faster hip flexion for the next step’s outreach. Besides, running is concentric. For every thing, turn turn, there is a time and a purpose…