Machine Single-Leg Leg Curl
A unilateral isolation exercise using a leg curl machine to target the hamstrings through knee flexion, helping build strength, address imbalances, and improve symmetry for hypertrophy and rehab goals.
About Exercise
Equipment
Leg Curl Machine
Difficulty
2/5 • Intermediate
Primary Muscle Groups
Hamstrings
Secondary Muscles
Calves
Accessory Muscles
Glutes, Abs
Popularity Score
7
Goals
Training Style
Setup Requirements
Requires Rack
No
Requires Bench
No
Requires Spotter
No
Space Needed
Small
Noise Level
Low
Muscle Breakdown
View Muscle MapHamstrings
10/10Biceps Femoris, Semitendinosus, Semimembranosus
Calves
4/10Gastrocnemius
Glutes
2/10Abs
2/10Programming
Typical Rep Range
8-15 reps
Rest Between Sets
60-90 seconds
How to Perform
Adjust the seated leg curl machine so the pivot aligns with your knee and the ankle pad rests above your heels. Sit upright with back against the pad, secure thighs, and extend one leg fully while keeping the other relaxed.
- Exhale and flex your knee to curl the pad toward your glutes, squeezing the hamstring.
- Hold the contraction briefly at the top.
- Inhale and slowly extend your leg back to the start, maintaining control.
- Keep hips and torso stable without lifting.
- Switch legs after completing reps on one side.
Coaching Tips
Form Cues
- Squeeze hamstrings at top
- Keep movement slow
- Neutral spine always
- Toes pointed slightly
Breathing
Exhale during the curl and inhale as you extend your leg, bracing your core throughout.
Tempo
2-1-2
Range of Motion
Extend leg fully without locking the knee; curl until heel nears glutes without hips rising.
Safety
Safety Notes
- Avoid if acute knee pain exists
- Align knee with machine pivot
- Start with light weight
- Do not hyperextend knee
Spotting
Not typically needed; machine provides safety, but use pin for heavy loads.
Common Mistakes
- Using momentum to swing weight
- Arching lower back
- Partial range of motion
- Locking knees at bottom
When to Avoid
- Acute hamstring strain
- Knee joint instability
- Lower back injury
Flexibility Needed
- Adequate knee flexion range
- Hip stability
Build Up First
- Familiarity with machine adjustments
- Basic hamstring activation
Also known as
Single-Leg Seated Leg Curl, Single-Leg Lying Leg Curl, Single-Leg Standing Leg Curl, Unilateral Hamstring Curl
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