What should I feel during Hack squat?

Quads load through full range without lower back involvement.

What are common mistakes with Hack squat?

Stopping short of parallel — cuts quad recruitment; Heels raised high — shifts load off quads; Knees caving inward on the drive

How do I progress Hack squat?

Add load when depth and knee tracking hold across all sets.

What can I do instead of Hack squat?

Leg press, Goblet squat, Pendulum squat

Hack squat

Shoulder pads locked, heels mid-plate, knees track over toes.

family=hack squatpattern=squatforce=pushmechanic=compoundequipment=machine

Muscles

muscle emphasis · training guidance

quadsPRIME

glutes68

Primary: quads
Supporting: glutes

Mechanics

Pattern: squat
Equipment: machine
Geometry: 90° Alignment
Target feel: Quads load through full range without lower back involvement.
Progression: Add load when depth and knee tracking hold across all sets.
Regression: Leg press if shoulder pad position is uncomfortable.

Common errors

Stopping short of parallel — cuts quad recruitment
Heels raised high — shifts load off quads
Knees caving inward on the drive

Programming by goal

Goal	Sets × reps	Effort cap	Tempo
Strength	3 × 3-6	RPE ≤ 9	2-0-X-0
Muscle growth	3 × 8-12	RPE ≤ 8	3-1-1-0
Endurance	3 × 15-25	RPE ≤ 7	2-0-2-0

Engine defaults for one exercise. Adjust load so every rep stays within the listed effort cap.

Equipment context

The machine fixes the movement path, reducing stabilizer demand and letting you focus on the target muscle.

Substitutions

Lying leg curl Shared equipment: machine · Antagonist pairing: quads / hamstrings
Seated leg curl Shared equipment: machine · Antagonist pairing: quads / hamstrings
Cyclist squat Same pattern: squat
Front squat Same pattern: squat
Knee-over-toe step-up Same pattern: squat

See all 33 quads exercises in the Atlas

Progression ladder

Beginner / regression: Leg press if shoulder pad position is uncomfortable.
Standard: Hack squat
Advanced / progression: Add load when depth and knee tracking hold across all sets.

Atlas metrics

Movement pattern: squat
Primary target: quads
Supporting muscles: glutes
Equipment: machine
Joint geometry: 90° Alignment
Alternatives: 3 substitutions

Evidence & limits

Last reviewed against peer-reviewed biomechanics references. Exercise descriptions are framed as training guidance, not medical advice.

Source: ExRx.net Exercise & Muscle Directory

Joint-profile source set: This exercise maps to the repository's sourced squat record with upright-seat support. The source brief groups ExRx, NSCA, and ACSM material; it does not retain a per-record source split.

Eccentryx is fitness software. It is not a medical device and is not intended to diagnose, treat, cure, or prevent any disease, injury, or medical condition. Consult a licensed physician before beginning any exercise program.

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FAQ

How do I set up Hack squat?: Shoulder pads locked, heels mid-plate, knees track over toes.
What should I feel during Hack squat?: Quads load through full range without lower back involvement.
What are common mistakes with Hack squat?: Stopping short of parallel — cuts quad recruitment; Heels raised high — shifts load off quads; Knees caving inward on the drive
How do I progress Hack squat?: Add load when depth and knee tracking hold across all sets.
What can I do instead of Hack squat?: Leg press, Goblet squat, Pendulum squat

Hack squat verified exercise line-art diagram.

The movement · Knee (drive) 120°→0° · Hip 175°→90°

Hack squat: squat pattern, 2400 ms rep trace, engine-derived.

Train Hack squat in Gym Mode → Browse the public Atlas →