vertical oscillation
– cm
duration
– s
samples
–
est. rate
– Hz
hip height — zero-phase (filtfilt), peaks aligned to footstrike · target band 6–9 cm
vertical acceleration — m/s² · toggle raw to see what the fusion recovers from
steps
–
push-off impulse
– m/s
braking impulse
– m/s
push-off L/R asym
– %
stride mechanics — forward (travel-axis) accel · red = braking after footstrike, green = push-off · vertical lines = detected footstrikes
Forward axis is found by PCA (direction of max horizontal accel = travel). Impulse is m/s of velocity change delivered to the trunk — net COM propulsion, not ankle power. L/R asymmetry compares alternating steps. Pelvic tilt during the run: mean –°, range –° (relative to mounting; needs a neutral cal for absolute APT).
Cutoff must sit below stride (~2.5–3 Hz) but above drift. Too high flattens real bounce; too low lets drift leak back in. Record once, drag the slider, watch the trace converge.