Smart Workout Diary

Single-Leg Hack Squat

The single-leg hack squat is a unilateral lower-body exercise performed on a hack squat machine. It primarily trains the quadriceps while also challenging the glutes and helping address side-to-side strength differences. It supports leg strength, muscle development, and controlled single-leg knee-dominant training.

Demonstration

Single-Leg Hack Squat — demonstration 1
Single-Leg Hack Squat — demonstration 2

Instructions

  1. Set up the machine with a manageable load and adjust the shoulder pads and safety stops so you can use a comfortable range of motion.
  2. Place one foot on the platform around shoulder-pad width from the center, keeping the whole foot planted. Keep the non-working leg off the platform and clear of moving parts.
  3. Brace your abdomen, press your back and shoulders into the pads, unlock the safeties, and begin with the working knee softly extended rather than locked.
  4. Lower under control by bending the working knee and hip, keeping the knee tracking in line with the toes and the heel in contact with the platform.
  5. Descend only as far as you can maintain a stable pelvis, neutral back contact with the pad, and comfortable knee alignment.
  6. Press through the whole foot to return to the start without snapping the knee straight. Complete the set, secure the safeties, then repeat on the other leg.
Muscle Group
Quads
Other Muscle Groups
Glutes
Type
Strength
Mechanics
Compound
Equipment
Machine Strength
Difficulty
Intermediate

Technique tips

  1. Start lighter than expected. Unilateral loading can make a familiar machine exercise substantially more demanding.
  2. Keep pressure distributed through the heel, midfoot, and forefoot; do not let the heel lift.
  3. Control the descent and avoid bouncing out of the bottom position or forcing depth.
  4. Use the same foot position, range of motion, and controlled repetitions on both sides.
Exercise library