This is the 2D side-view companion to the 3D gait-cycle lab, driven by the exact same normalized keyframe table of hip, knee and ankle angles across a 0–100% walking cycle (heel strike → loading response → midstance → terminal stance → toe-off → initial/mid/terminal swing → next heel strike), cosine-interpolated between keyframes for smooth motion.
- Normal Walking — reciprocal legs offset by 50% of the cycle, with the classic ~60% stance / ~40% swing split and two brief double-support windows.
- Trendelenburg Gait — weak hip abductors on the stance leg let the opposite pelvis drop during single-limb support, peaking mid-stance, with a compensatory trunk lurch over the stance hip.
- Foot Drop — the ankle fails to dorsiflex during swing, so the toes drag near the ground instead of clearing it (drawn in red), often forcing a higher "steppage" knee lift to compensate.
Scrub the timeline manually or press play to watch the sub-phase advance automatically; the joint-angle graph traces hip/knee/ankle across the whole cycle with a live marker at the current position.