What Muscles Do Pin Squats Work? Complete Anatomy Guide

Pin squats (also called Anderson squats after Paul Anderson) start from the bottom position—bar resting on safety pins—and require you to generate force from a complete dead stop. This builds explosive starting strength and eliminates the stretch reflex.

Quick Answer

Primary muscles: Quadriceps (maximum), glutes (maximum), core (very high), erector spinae (very high)

Secondary muscles: Hamstrings (high), adductors (moderate-high), upper back (high)

Pin squats emphasize concentric-only strength and the ability to generate force without any momentum or elastic assistance.

Why Start from the Pins?

No Stretch Reflex

Normal squats use the stretch-shortening cycle—you bounce out of the hole. Pin squats eliminate this, requiring pure muscular force.

Dead Stop = Honest Strength

You can't hide weakness with momentum. Either you're strong enough to move it from the pins, or you're not.

Sticking Point Training

Set pins at your weak point height. Train specifically where you struggle.

Starting Strength

Builds the ability to generate force from zero velocity—useful for sports and lifting.

The Pin Squat Movement

Setup

| Component | Position | |-----------|----------| | Pins | Set at desired height (parallel or above) | | Bar | Resting on pins, no tension | | Body | Under bar in squat position | | Breath | Big breath before lifting |

The Concentric (Only Phase)

| Muscle | Action | Activation | |--------|--------|------------| | Quadriceps | Knee extension from dead stop | Maximum | | Glutes | Hip extension from dead stop | Maximum | | Core | Bracing against load | Very High | | Erector spinae | Maintaining spinal position | Very High | | Upper back | Supporting bar | High |

Generate force against a completely static bar—pure concentric strength.

The Return

| Muscle | Action | Activation | |--------|--------|------------| | All muscles | Controlled descent | Eccentric (if doing reps) |

Lower back to pins. Reset completely before next rep—no bouncing off pins.

Primary Muscles Worked

Quadriceps

Your quads work maximally from the dead stop. Without elastic rebound, they must generate all the force to initiate movement. Pin squats build quad strength that transfers to the hardest part of regular squats.

Gluteus Maximus

Your glutes fire maximally from the bottom position. Starting from a dead stop requires powerful hip extension without assistance.

Core

Your core braces intensely to:

• Protect the spine
• Transfer force efficiently
• Maintain position under load

Erector Spinae

Your spinal erectors work at very high intensity to maintain back position when generating force from a dead stop.

Secondary Muscles

Hamstrings

Assist hip extension, working alongside glutes.

Adductors

Provide stability and assist with hip extension.

Upper Back

Supports the bar and maintains position.

Pin Height Options

Below Parallel (Deep)

• Maximum quad and glute stretch
• Hardest position
• Builds strength from the hole

At Parallel

• Standard depth
• Most common setting
• Good all-around strength builder

Above Parallel (Quarter Squat Range)

• Highest loading potential
• Builds lockout strength
• Less range of motion

At Sticking Point

• Set where you fail in regular squats
• Specifically addresses weakness
• Targeted training

Pin Squat vs Regular Squat

| Aspect | Pin Squat | Regular Squat | |--------|-----------|---------------| | Stretch reflex | None | Yes | | Starting position | Dead stop | Standing | | Momentum | None | Yes | | Weight typically | Less | More | | Primary benefit | Starting strength | Overall strength | | Eccentric phase | Optional | Yes |

Pin squats are harder from the same position because there's no elastic assistance.

Programming Pin Squats

For Starting Strength

• Heavy singles or doubles
• From parallel or just below
• Full reset between reps
• 5-8 sets of 1-2 reps

For Weak Point Training

• Set pins at failure height
• Moderate to heavy weight
• 3-5 sets of 2-4 reps
• Build strength specifically where you're weak

As Accessory

• After main squat work
• 3-4 sets of 3-5 reps
• Addresses sticking points
• Moderate loading

For Power Development

• Explosive intent
• Moderate weight (60-75%)
• Focus on bar speed
• 4-6 sets of 2-3 reps

Technique Cues

Setup

1. Set pins at desired height
2. Position bar on pins
3. Get under bar in squat position
4. Hands on bar, feet set
5. Completely relaxed—no tension yet

The Lift

1. Big breath, brace hard
2. Build tension against bar
3. Explode from dead stop
4. Drive through full extension
5. Lock out at top

The Reset

1. Lower under control (or drop if single)
2. Bar returns to pins
3. Complete stop—release all tension
4. Reset position
5. Rebrace and repeat

Common Mistakes

| Mistake | Why It's Bad | Fix | |---------|-------------|-----| | Bouncing off pins | Not a pin squat | Full stop each rep | | Staying tight between reps | Defeats purpose | Release tension on pins | | Starting with tension | Not a dead stop | Relax, then explode | | Pin too high | Limited benefit | Set at challenging depth | | Rushing | Poor position | Reset fully each rep |

Dead Stop Is Key

The defining feature of pin squats is the dead stop:

✓ Bar rests completely on pins ✓ You release muscular tension ✓ No elastic energy stored ✓ Each rep starts from zero

If you're maintaining tension between reps, you're doing pause squats—different exercise.

Weight Expectation

Most lifters can pin squat from parallel 80-90% of their regular squat. Factors:

• How much you rely on stretch reflex
• Starting strength capacity
• Pin height

Lower pins = harder. No stretch reflex = harder.

Who Should Do Pin Squats

Excellent For:

• Powerlifters with sticking point issues
• Athletes needing starting strength
• Those who bounce excessively in the hole
• Lifters building max strength
• Anyone wanting to develop explosive power

Not Ideal For:

• Complete beginners (learn regular squat first)
• Those with back issues (high spinal loading at disadvantaged position)
• Every session (specialty movement)

Benefits Beyond Muscle

Confidence Building

Conquering weight from a dead stop builds mental strength.

Honest Assessment

Reveals true strength without momentum assistance.

Sport Transfer

Starting strength transfers to explosive athletic movements.

Safety Learning

Practice bailing to pins—valuable skill.

Sample Programming

Sticking Point Block (4 Weeks)

• Pins set at sticking point
• Week 1: 5x3 @ 70%
• Week 2: 5x2 @ 75%
• Week 3: 6x2 @ 80%
• Week 4: 4x1 @ 85%

Weekly Inclusion

• Day 1: Competition squat
• Day 2: Pin squat at parallel (3x3)

Explosive Power

• Pin squat: 6x2 @ 60%
• Maximum bar speed
• Full reset between reps

Key Takeaways

✅ Pin squats work quads, glutes, core, and erectors from dead stop
✅ No stretch reflex—pure muscular force required
✅ Full stop on pins between reps—release tension
✅ Builds starting strength and explosiveness
✅ Set pins at sticking point for targeted training
✅ Expect 10-20% less weight than regular squat
✅ Named after Paul Anderson—legendary lifter
✅ Great for breaking through plateaus

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Pin squats are brutally honest. The bar sits on the pins, you get under it, and you either move it or you don't. No bounce, no momentum—just you against the iron. Build the starting strength that makes everything else easier.