Kneeling Leg Curl

Elite hamstring builder — one of the most challenging bodyweight hamstring exercises, building exceptional eccentric strength and injury resilience

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⚡ Quick Reference

Aspect	Details
Pattern	Hinge (Knee Flexion)
Primary Muscles	Hamstrings
Secondary Muscles	Glutes, Core, Calves
Equipment	Partner or anchor point
Difficulty	⭐⭐⭐ Advanced
Priority	🟡 Supplementary

Movement Summary

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🎯 Setup

Starting Position

1. Ankle anchor: Have partner hold ankles firmly, or secure under heavy barbell/immovable bench
2. Kneeling position: Knees on pad, tall kneeling posture
3. Hips: Fully extended, straight line from knees to shoulders
4. Core: Maximally braced, ribs down
5. Arms: Crossed over chest or ready at sides to catch fall
6. Head: Neutral, looking forward

Anchor Options

Option	Setup	Pros/Cons
Partner	Partner kneels on your calves	Adjustable assistance, safest
Loaded Barbell	Hook ankles under barbell	Stable, but no assistance
Bench/Equipment	Wedge ankles under bench	Accessible, but check stability
Dedicated Rig	GHD or Nordic curl bench	Best option if available

Setup Cue

"Tall kneeling position, hips fully extended, ankles locked down, body straight as a plank"

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🔄 Execution

The Movement

🔝 Starting Position

What's happening: Tall kneeling, body vertical, ready to lower

1. Kneeling upright with ankles secured
2. Hips fully extended (not sitting back)
3. Core maximally braced
4. Body in straight line from knees to head
5. Arms ready to catch

Feel: Hamstrings already engaged maintaining vertical position, core tight

⬇️ Lowering (ECCENTRIC)

What's happening: Controlled forward lean, resisting with hamstrings

1. Keep hips extended — don't break at hips
2. Lower body forward as one unit
3. Hamstrings work eccentrically to control descent
4. Fight gravity for as long as possible
5. Lower as far as you can control (often 45-60° from vertical)
6. Catch yourself with hands before losing control

Tempo: 3-5+ seconds (as slow as possible)

Feel: Intense hamstring burn and stretch, full-body tension

THIS IS THE MAIN WORK — the eccentric lowering is where the magic happens.

⏸️ Bottom Position

What's happening: Caught yourself with hands, full hamstring stretch

1. Hands on ground in push-up position
2. Body lowered as far as hamstrings could control
3. Hamstrings at maximum stretch
4. Core still braced

Common error here: Breaking at hips on the way down — maintain hip extension throughout the eccentric.

⬆️ Push Back Up

What's happening: Use hands to push back to starting position

1. Push with arms to assist return to vertical
2. Hamstrings pull as much as they can
3. Most people need significant arm assistance
4. Return to tall kneeling position
5. Reset for next rep

Tempo: 1-2 seconds with arm help

Feel: Difficult concentric, arms doing most of the work initially

Key Cues

Primary Cues

• "Hips stay extended" — straight line from knees to shoulders
• "Fight gravity as long as possible" — slow eccentric is key
• "Lower as one unit" — don't break at hips
• "Catch before you crash" — hands ready to save you

Tempo Guide

Goal	Tempo	Example
Strength	5-0-1-0	5s+ eccentric, push up fast
Hypertrophy	4-1-1-0	4s eccentric, brief pause, push up
Beginner	3-0-2-0	3s eccentric, assisted concentric

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💪 Muscles Worked

Activation Overview

Primary Movers

Muscle	Action	Activation
Hamstrings	Knee flexion — resisting knee extension under extreme eccentric load	██████████ 95%

Secondary Muscles

Muscle	Action	Activation
Gastrocnemius	Assists knee flexion	██████░░░░ 60%
Glutes	Maintains hip extension	██████░░░░ 55%
Core	Prevents hip flexion, maintains rigid torso	███████░░░ 65%

Stabilizers

Muscle	Role
Erector Spinae	Maintains torso rigidity
Hip Flexors	Maintain hip extension position
Entire Core	Prevents body breaking at hips

Unique Benefit

Extreme eccentric overload — one of the few bodyweight exercises that provides true eccentric overload for hamstrings. Builds exceptional hamstring strength and resilience to injury.

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⚠️ Common Mistakes

Mistake	What Happens	Why It's Bad	Fix
Breaking at hips	Hips flex on descent	Reduces hamstring load	Keep hips extended throughout
Dropping too fast	Falling instead of lowering	Loses eccentric benefit	Slow and controlled descent
Not using arms	Trying to curl all the way up	Impossible for most, risks injury	Use arms generously on concentric
Starting too advanced	Attempting full ROM immediately	Risk of extreme soreness/injury	Start with smaller ROM
Ankles not secure	Slipping during movement	Loss of control, injury risk	Ensure firm anchor

Most Common Error

Breaking at the hips during descent. This turns it into a hip hinge instead of keeping the hamstrings under maximal tension. Keep hips locked in extension.

Self-Check Checklist

• Ankles firmly secured
• Hips stay extended throughout eccentric
• Body lowers as one straight unit
• Eccentric is slow and controlled (3+ seconds)
• Hands ready to catch at bottom

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🔀 Variations

By Difficulty

Easier (Regressions)

Variation	How	When to Use
Partner-Assisted	Partner helps lift you back up and can assist descent	First time trying exercise
Short ROM	Only lower 30-45° from vertical	Building strength progressively
Band-Assisted	Resistance band under arms provides upward force	Need more help with concentric
Slider Leg Curl	Feet on sliders, bridge and curl	Building toward kneeling curl

Standard

Variation	How	Emphasis
Bodyweight Full ROM	Lower as far as possible, push back up	Standard progression
Eccentric Focus	Super slow eccentric (5+ seconds)	Maximum eccentric stimulus
Pause at Bottom	2-3 second hold at bottom	Isometric strength

Harder (Progressions)

Variation	How	When to Use
Minimal Hand Assist	Use hands as little as possible	Getting very strong
Full Nordic Curl	Curl all the way up unassisted	Elite level
Weighted Nordic	Hold weight plate to chest	Beyond elite

By Target

Target	Variation	Change
Pure Eccentric	Lower only, full arm push up	Maximum eccentric focus
Isometric	Hold at various angles	Build strength at weak points
Concentric Focus	Partner assist down, you pull up	Rare — most can't do this
Endurance	Lighter assistance, more reps	10-15 rep range

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📊 Programming

Rep Ranges by Goal

Goal	Sets	Reps	Rest	Notes
Strength	3-4	3-6	120-180s	Very slow eccentrics
Hypertrophy	3-4	6-10	90-120s	Controlled tempo
Eccentric Only	3-4	5-8	120s	5+ second eccentrics

Workout Placement

Program Type	Placement	Rationale
Lower body	After main lifts	Accessory hamstring work
Hamstring focus	Primary exercise	Elite hamstring builder
Injury prevention	Regular inclusion	Builds hamstring resilience
NOT a warmup	Never first	Too demanding

Progression Scheme

How to Progress

Start with heavy partner assistance and limited ROM. Progress by reducing assistance and increasing ROM. Most people work on this for months before doing full unassisted reps.

Important Notes

• Extreme DOMS warning: First time doing these, expect severe hamstring soreness for 3-5 days
• Start conservatively: Do fewer reps than you think you can for first session
• Build gradually: Add 1-2 reps per week maximum
• Frequency: 1-2x per week is plenty — these are very demanding

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🔄 Alternatives & Progressions

Exercise Progression Path

Regressions (Easier)

Exercise	When to Use
Slider Leg Curl	Building hamstring strength
Physioball Leg Curl	Learning hamstring curl pattern
Partner-Assisted Version	First time attempting

Progressions (Harder)

Exercise	When Ready
Reduced Hand Assist	Can control full eccentric well
Full Nordic Curl	Can do 6+ reps with minimal hand push
Weighted Nordic	Elite hamstring strength

Alternatives

Alternative	When to Use
Lying Leg Curl	In gym with machines
Slider Leg Curl	Want less intense option
Romanian Deadlift	Want to load hamstrings differently

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🛡️ Safety & Contraindications

Who Should Be Careful

Condition	Risk	Modification
Hamstring injury history	Re-injury risk if progressed too fast	Start with extreme caution, heavy assistance
Knee pain	High knee stress	May need to avoid
Lower back issues	Compensation during movement	Focus on core bracing
New to eccentric training	Severe DOMS likely	Start very conservatively

Stop Immediately If

• Sharp pain in hamstring (could indicate strain)
• Acute knee pain
• Unable to control descent

Safety Tips

• Essential: Start with MUCH less volume than you think you can do
• First session: Do 2-3 reps only, wait 3-4 days to assess soreness
• Progress slowly: Add 1-2 reps per week maximum
• Use padding: Thick pad or mat under knees
• Secure anchor: Double-check ankle stability before each set
• Hands ready: Always ready to catch yourself

DOMS Warning

Expect extreme delayed onset muscle soreness (DOMS) for 3-5 days after your first session. This is normal but can be debilitating if you do too much. Start with 2-3 reps maximum.

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🦴 Joints Involved

Joint	Action	ROM Required	Stress Level
Knee	Flexion/extension under eccentric load	Full (0-90°+)	🟡 Moderate-High
Hip	Maintained extension	Isometric at full extension	🟢 Low
Ankle	Stabilization	Plantarflexion	🟢 Low

Joint Considerations

Moderate-high knee stress, but the controlled eccentric nature actually builds knee resilience. However, anyone with current knee issues should be cautious.

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❓ Common Questions

I can barely do one rep. Is this normal?

Absolutely normal. This is an elite-level exercise. Most people need partner assistance or band assistance for months before doing unassisted reps. Start with heavy assistance and short range of motion.

How sore will I be after my first time?

Expect extreme hamstring soreness for 3-5 days, especially if you do too many reps. Start with 2-3 reps only for your first session, even if you could do more.

Should I use my arms to push back up?

YES! Use your arms as much as needed. The eccentric (lowering) is the primary stimulus. Most people need significant arm push for months before they can curl back up.

How is this different from a Nordic curl?

Same exercise, different names. "Nordic hamstring curl" is the most common name. "Kneeling leg curl" describes the movement pattern. They're identical.

Will this prevent hamstring injuries?

Research strongly suggests Nordic curls significantly reduce hamstring injury rates, especially in athletes. The eccentric strength built here is highly protective.

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📚 Sources

Biomechanics & Muscle Activation:

• Mjølsnes, R., et al. (2004). Nordic curl injury prevention — Tier A
• van der Horst, N., et al. (2015). Hamstring eccentric strength — Tier A
• ExRx.net — Tier C

Programming:

• NSCA Essentials — Tier A
• Sports medicine protocols — Tier B

Injury Prevention:

• Petersen, J., et al. (2011). Nordic hamstring reduces injury by 51% — Tier A

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For Mo

When to recommend this exercise:

• User is advanced athlete looking for elite hamstring strength
• User wants injury prevention for hamstrings (especially runners, soccer players)
• User wants challenging bodyweight posterior chain work
• User has access to partner or anchor point

Who should NOT do this exercise:

• Beginners → Too advanced, risk of injury
• Acute hamstring injury → Wait for full recovery
• Severe knee pain → May aggravate condition
• No experience with eccentric training → Build up with easier exercises first

Key coaching cues to emphasize:

1. "Start with WAY fewer reps than you think — 2-3 reps only first session"
2. "Hips stay extended — lower as one straight unit"
3. "The lowering is the work — use arms to come back up"
4. "Expect extreme soreness for 3-5 days"

Common issues to watch for in user feedback:

• "These destroyed me" → Normal! Reduce volume significantly
• "I can't do even one" → Use partner assistance or try slider leg curls
• "My knees hurt" → Check padding, may need to avoid
• "I don't feel it in hamstrings" → Check form, probably breaking at hips

Programming guidance:

• For beginners: Don't recommend — too advanced
• For intermediate: Start with 2-3 reps, heavy assistance, 1x per week
• For advanced: Build to 3-4 sets of 6-10 reps over many months
• Progress SLOWLY — this exercise has high injury risk if progressed too fast

Critical safety notes:

• ALWAYS warn about severe DOMS
• ALWAYS emphasize starting with minimal volume
• ALWAYS ensure proper ankle anchoring
• Monitor for hamstring strain signs

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Last updated: December 2024