Burpee Broad Jump · Launch Vector (Takeoff)

Why this matters

The jump is a projectile, and the launch angle decides how far it travels. The textbook "45° is optimal" rule is for an idealised point mass — human broad jumps peak lower, around 25–40°, because athletes generate far more take-off velocity at shallower angles, and that extra speed outweighs the geometric ideal. Too vertical and you waste effort on hang time; too flat and the feet don't clear distance and you stumble.

Jump to a spot on the floor ahead, not up.

Note this is a body-lean proxy: we measure the ankle→shoulder line, which tracks the launch trajectory closely enough for coaching but reads slightly more upright than the true CoM velocity vector.

What good looks like

• The body launches on a forward-biased line, driving out across the floor.
• Distance per rep is high, so fewer total reps cover the 80 m.
• The line pairs with full leg extension (see Terminal Extension).

Common faults

Too Vertical (> 45°)

Jumping up instead of out. Hang time and gravity eat the effort — the classic economy leak after squat-loading.

Too Flat (< 20°)

A near-horizontal launch; the feet may not clear enough distance and the trunk pitches forward into a stumble on landing.

Coaching cues

• "Jump to a spot ahead" — biases the line forward.
• "Long, not high" — names the trade-off directly.
• Pitch the trunk forward first — the load's trunk pitch sets the launch angle up.

How to draw

1. Advance to the final frame before the toes leave the carpet.
2. First point: lateral malleolus (ankle).
3. Second point: acromion (shoulder).
4. The acute angle vs horizontal is the launch line.

Related measurements

• Terminal Extension (Takeoff) — same frame; confirms the leg drive is complete.
• Trunk Pitch (Load) — the posture that sets the launch angle.