Quads
Single Leg Hack Squat
The Single Leg Hack Squat is a strength exercise on a machine for your quads. Share of the load in the Zulta muscle model: quads (vastus lateralis) 21%, quads (vastus medialis) 17% and gluteus maximus 14%.
How to do it
- Set up in the hack squat with your back on the pad and the shoulder pads on your shoulders.
- Place one foot in the middle of the platform, directly under the hip, and let the other leg hang or rest off the platform.
- Release the safety and lower on the working leg until the thigh is about parallel.
- Keep the knee tracking over the middle toes as you descend.
- Push through the whole foot back up, then finish all reps before switching legs.
Tips
- Use a lighter load than you think: one leg carries the whole sled.
- Keep the hips square on the pad.
Common mistakes
- Letting the knee collapse inward.
- Twisting the pelvis off the pad.
- Pushing with the free foot on the platform.
Muscles worked by the Single Leg Hack Squat
Share per muscle in the Zulta muscle model. The model spreads the load of one rep over 40 muscles, based on EMG and biomechanics research.
Knees further forward shifts work to the quads. The machine or bar path takes over most of the trunk work. One side at a time. Knees and hips flex and extend together under load: the vasti and glute max are the prime movers, the adductors extend the hip from the bottom, and the erectors hold the torso.
Single Leg Hack Squat alternatives
Same equipment
Different equipment
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Make it harder
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Similar exercises
Frequently asked questions
What muscles does the Single Leg Hack Squat work?
Mainly the quads (vastus lateralis) and quads (vastus medialis). The gluteus maximus, adductors and quads (rectus femoris) assist.
Is the Single Leg Hack Squat good for beginners?
The Single Leg Hack Squat is rated intermediate. If you are new, learn the Decline Squat first and build up from there.
What is a good alternative to the Single Leg Hack Squat?
For example the Decline Squat, Smith Machine Hack Squat (Feet Forward) and Heels Elevated Goblet Squat. They train mostly the same muscles, some with different equipment.
How do you make the Single Leg Hack Squat harder?
Add weight or reps, or move on to the Front Squat and Pause Front Squat.
Sources
- Escamilla 2001, MSSE 33(1):127-141 (knee biomechanics of the squat)
- Kubo et al. 2019, Eur J Appl Physiol 119(9):1933-1942 (squat depth and adductors)
- Gullett et al. 2009, JSCR 23(1):284-292 (front vs back squat)
Log your sets in Zulta
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