Sandbag Lunge · Knee Lockout at Extension

Why this matters

HYROX requires the athlete to pass through full hip and knee extension between every step. The knee lockout is half of that standard. Keeping the knee slightly bent to stay low and rush into the next step earns a no-rep — and it also denies the leg its brief unload, so the quad stays under constant tension and fatigues faster.

This measurement also dictates pacing strategy: a true lockout supports a walk-and-lock rhythm; athletes who never lock are usually shuffling continuously (and risking no-reps).

What good looks like

• Knee reaching ~180° at the top of each step.
• A clear "stand tall" moment before the next lunge.
• A brief unload of the quad each rep.

Common faults

Bent Knee (< 160°)

The knee stays bent to keep the body low and rush the next step. A no-rep — and the quad never gets to rest.

Causes: rushing the pace, fatigue, or a continuous-shuffle style.

Effect: no-rep penalty, constant quad tension, faster burnout.

Partial (160–172°)

Almost locked — a judge could call it short. Finish the extension to secure the rep.

Coaching cues

• "Stand all the way tall" — drives full extension.
• "Walk and lock, don't shuffle" — sets a pacing rhythm that guarantees the standard.

How to draw

1. Pause at the highest point of the step, before the trailing foot passes the planted foot.
2. First line: greater trochanter → lateral femoral condyle (thigh).
3. Second line: lateral femoral condyle → lateral malleolus (shank).
4. Interior angle at the knee is the reading.

Related measurements

• Hip Lockout at Extension — the other half of the top-of-step standard.
• Hip Lockout at Extension — measured from the same shoulder→hip→knee→ankle chain as this knee lockout.