Single-leg Box Squat

How to perform it

1. 1Preparation and positioning. Use a stable surface and enough clearance to step out safely. Establish the foot-pressure, depth, balance, and ascent standard before adding speed or external assistance. Place a stable box behind the working leg at a height that permits a controlled touch without collapsing onto it.
2. 2Starting position. Set the working foot with a stable tripod, brace the trunk, and establish the balance or support strategy before descending. Balance on one leg with the free leg positioned as declared and the trunk stacked over the foot.
3. 3Descent. Flex the hip and knee under control while the knee tracks over the foot as the individual anatomy allows. Lower toward the box under control while maintaining foot pressure and a repeatable knee path.
4. 4Bottom position. Reach the same depth or contact marker without bouncing or losing the foot tripod. Touch the box softly without relaxing or shifting the pelvis to the side.
5. 5Ascent / lockout. Drive through the whole foot and extend the hip and knee to the defined top position. Drive away from the box and stand without pushing from the free leg or hands.
6. 6Breathing and bracing. Brace the trunk before the descent, maintain pressure through the hardest portion, and breathe rhythmically between repetitions when the exercise is not being performed as a maximal effort.
7. 7Valid rep. A valid repetition starts and ends in the prescribed stance, reaches the same depth, and returns without an unplanned step, hand support, or loss of balance. The box height, touch standard, and unassisted return remain constant.

Common mistakes

• Losing the foot tripod

  Fix: Keep pressure through the heel, first metatarsal, and fifth metatarsal without gripping the floor excessively.

• Uncontrolled pelvic collapse

  Fix: Reduce depth or use support until the pelvis and trunk remain repeatable.

• Using the free limb or hands

  Fix: Treat assistance as a defined regression rather than an unplanned push-off.

• Sitting and rocking

  Fix: Raise the box or reduce load so the touch remains a controlled change of direction.

Safety

• Unilateral loading, deep knee flexion, landing, balance, and multiplanar control can change local demand; a visible knee position is not by itself a diagnosis or injury prediction.
• Choose a setup, load, assistance level, and exit strategy that allow the defined standard to be maintained; do not train through acute, sharp, electric, or worsening symptoms.

Progressions & alternatives

• regressionAssisted Pistol Squat— Add support when balance or the box touch is not controlled.
• progressionPistol Squat— Lower the box height or remove it after the full range is repeatable.
• alternativeSkater Squat— Use a different unilateral squat with a rear-leg counterbalance.
• prerequisiteDragon Squat— A controlled unilateral box squat can build the base for multiplanar depth.