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Form fundamentals

Posture & Lean

How forward (or backward) you lean from the ankles while running.

Healthy range: 3–12° forward lean

What it is

A small forward lean from the ankles — not the waist — lets gravity assist your forward motion. Too upright and you waste energy pushing off; too hinged at the waist and you collapse through the hips and stress the lower back.

Why it matters

Posture is upstream of almost every other form issue. A poor lean masquerades as a cadence problem, a hamstring problem, or a knee problem. Fix the lean and other things often improve on their own.

How we detect it

We measure the angle from your mid-hip to your nose against vertical, frame by frame. A healthy running lean sits between 3° and 12° forward. Negative values mean you're leaning back (braking with every step); >15° usually means you're hinged at the waist.

How to fix it

Most runners with a posture grade below B are actually weak in the posterior chain — glutes and core can't hold the pelvis stable, so the upper body compensates. Strengthen the chain first, then cue "tall, falling forward" on easy runs.

Recommended drills

  • Wall angels (3x15)
  • Planks (3x60s)
  • Single-leg deadlifts (3x10/side)

Run these 2-3x per week. Expect to feel a change in form 4-6 weeks in.

Common symptoms when this is off

Lower back tightnessHamstring tightnessQuad-dominant running