Post 4 — Ground Contact Area: The Missing Context for Force Distribution

Why contact area matters

• Context for pressure: Pressure = force / area. Without area, high pressures from small contact patches can be misread (and vice versa).
• Clinical & rehab use: Contact area/time are core variables in clinical gait analysis for diagnosis, treatment selection, and outcome evaluation.
• Stability and mechanics: Together with COP path, area distribution changes indicate altered mechanics and orthotic/technique effects.

Why many wearables skip it

Contact area requires a sufficiently dense spatial grid to detect onset/offset and regional coverage. Sparse layouts reduce area to crude approximations. A high-density matrix (like walkpad's) yields robust area & contact-time metrics per step.

Selected references