Hack Squat
Quad-focused machine work — builds massive quadriceps with back support and fixed movement path
⚡ Quick Reference
🎯 Setup
Machine Position
- Back against pad: Entire back in contact with back pad
- Shoulder pads: Under shoulders, comfortable position
- Foot position: Shoulder-width on platform, mid-platform
- Safety catches: Engaged until ready to start
🔄 Execution
The Movement
- ⬇️ Descending
- ⬆️ Ascending
- Release safety catches
- Lower under control by bending knees
- Keep back flat against pad
- Descend until thighs parallel or deeper
Tempo: 2-3 seconds
- Push through heels and mid-foot
- Extend knees to return to start
- Don't lock out completely at top
- Maintain back contact
Tempo: 1-2 seconds
Key Cues
- "Back stays glued to pad" — maintain contact
- "Push through heels" — proper force distribution
- "Control the descent" — no free-falling
💪 Muscles Worked
| Muscle | Action | Activation |
|---|---|---|
| Quadriceps | Knee extension | █████████░ 95% |
| Glutes | Hip extension | ██████░░░░ 60% |
Hack squats heavily emphasize quads due to the fixed path and back support, making it excellent for quad hypertrophy.
⚠️ Common Mistakes
| Mistake | Fix |
|---|---|
| Heels lifting | Foot position higher on platform |
| Back leaving pad | Lighter weight, focus on control |
| Too narrow stance | Widen for comfort and depth |
| Bouncing at bottom | Control descent, pause briefly |
🔀 Variations
- Stance Variations
- Foot Position
- Execution Variations
Narrow Stance Hack Squat
- Feet closer together (hip-width)
- Emphasizes outer quad sweep (vastus lateralis)
- Requires good ankle mobility
Wide Stance Hack Squat
- Feet wider than shoulder-width, toes out
- Greater adductor involvement
- May feel more comfortable for some
📊 Programming
| Goal | Sets | Reps | Rest |
|---|---|---|---|
| Hypertrophy | 3-4 | 10-15 | 90-120s |
| Strength | 4-5 | 6-10 | 2-3 min |
| Endurance | 2-3 | 15-20+ | 60s |
Placement: After main squats or as primary leg exercise
🔄 Alternatives & Progressions
Alternatives
| Exercise | When to Use | Link |
|---|---|---|
| Leg Press | Less quad emphasis, more comfortable | |
| Back Squat | Free weight alternative | |
| Front Squat | Similar quad emphasis | |
| Pendulum Squat | Different machine feel |
Progressions
| Progression | When Ready |
|---|---|
| Add pause at bottom | Master standard form |
| Single-leg hack squat | Strong bilateral base |
| Tempo work (4-0-1-0) | Need more time under tension |
Regressions
| Regression | When Needed |
|---|---|
| Leg Press | Need less knee stress |
| Goblet Squat | Building basic patterns |
| Bodyweight squat | Learning movement |
🛡️ Safety & Contraindications
Who Should Be Careful
| Condition | Risk | Modification |
|---|---|---|
| Knee pain | May aggravate | Use leg press, reduce depth |
| Low back issues | Compression | Ensure back stays on pad |
| Hip impingement | Limited depth | Reduce ROM, widen stance |
Safety Tips
- Always use safety catches when getting in/out
- Start light to learn the machine's movement path
- Don't lock knees completely at top
- Keep back flat against pad throughout
- Sharp knee pain (not muscle burn)
- Lower back leaves pad
- Numbness or tingling in legs
🦴 Joints Involved
| Joint | Movement | ROM |
|---|---|---|
| Knee | Flexion/Extension | 0-120° |
| Hip | Flexion/Extension | 0-100° |
| Ankle | Dorsiflexion | 15-25° |
Joint Considerations
- Knee: Primary working joint - receives most stress
- Hip: Secondary - less stress than free squats due to back support
- Ankle: Requires adequate mobility for full depth
❓ Common Questions
Is hack squat bad for knees? Not inherently. The fixed path actually makes it safer for many people. However, if you have existing knee issues, start light and monitor how you feel.
Hack squat vs leg press? Hack squat emphasizes quads more due to the upright torso. Leg press allows heavier loads but with less quad isolation.
How deep should I go? At least to parallel (thighs parallel to platform). Deeper is fine if you have the mobility and it doesn't cause discomfort.
Can hack squat replace barbell squats? It can be a primary quad builder, but free weight squats offer more stability and core demands. Use both ideally.
📚 Sources
- Schoenfeld, B. J. (2010). Squatting kinematics and kinetics and their application to exercise performance. Journal of Strength and Conditioning Research
- Escamilla, R. F. (2001). Knee biomechanics of the dynamic squat exercise. Medicine & Science in Sports & Exercise
- Contreras, B. (2019). Glute Lab: The Art and Science of Strength and Physique Training
When to recommend:
- User wants quad development
- User has back issues (machine provides support)
- Alternative to free weight squats
Who should avoid:
- Knee pain → Try Leg Press
Key cues:
- "Keep your back against the pad"
- "Push through your heels"
- "Control the weight down"
Programming:
- After squats: 3x10-12
- As primary movement: 4x8-12
- Rest: 90-120 seconds
Last updated: December 2024