Wall Ball · Knee Valgus at Depth

Why this matters

Wall ball is a hundred squats under fatigue, thrown at speed. The bottom of every rep is where the knee is most likely to cave inward, and at that depth and rep count a valgus collapse quietly accumulates ligament stress. It also leaks power: a knee that buckles inward isn't driving straight up into the throw.

A knee that tracks over the foot keeps injury risk low. A small valgus shift is common under the fatigue and speed of the station — not yet injurious, but the sort of fault that a hundred reps will find.

What good looks like

From the front, at the deepest point of the squat, the thigh and shank line up straight down to the foot — the knee points over the middle of the foot. It holds that line as the athlete explodes up into the throw, even as the set drags on.

Reading the result

• Neutral (tracks over the foot): knee tracks correctly; low injury risk.
• Moderate valgus: a small inward shift under fatigue or load; worth correcting before the rep volume compounds it.
• Large valgus: a pronounced inward collapse at depth — the priority fault to fix on this station.

Coaching cues

• "Knees out, drive through the floor" — pushes the knee back out over the foot on the way up.
• Off the platform: glute-med / abductor strength so the knee holds its line deep into the set.

How to mark

1. Use an anterior-view clip and pause at the bottom of the squat.
2. Thigh: lead hip → knee centre.
3. Shank: knee centre → ankle centre.
4. The tool reports the deviation — inward collapse reads as valgus.

Related measurements

• Squat Depth Standard — same frame; whether the rep hit legal depth, which is where valgus is most likely.
• Trunk Angle at Catch — the upright catch that sets up a knee-tracking descent.