The stickman is ten point-masses (head, neck, chest, hip, two hands, two knees, two feet) connected by fixed-length distance constraints and integrated with Verlet integration — position updates from the previous two frames rather than an explicit velocity variable, which keeps the joint chain stable even after a hard impact:
x(t+dt) ≈ 2x(t) − x(t−dt) + a·dt²
Twelve constraints (spine, arms, both legs, plus torso-to-knee braces) are relaxed six times per physics step using Gauss–Seidel-style projection, which is what keeps the figure roughly rigid while standing but lets it fold and tumble like a ragdoll once a kick displaces one joint's velocity. Each kick style feeds a different target joint and force direction: a low sweep hits the front knee near-horizontally, a side kick drives straight through the hip, a roundhouse lands on the chest with a strong upward component, and a high kick strikes the head almost vertically — producing visibly different launch arcs from the same power setting.
- Impact force — the kick impulse's magnitude converted to a stylised kN reading.
- Air time — seconds the hip joint spends above the ground after the strike.
- Travel — horizontal displacement of the hip from the point of impact.
- Peak height — the highest point the hip reaches during flight.