Lying Leg Curl Single Leg
The Lying Leg Curl Single Leg is an advanced machine-based unilateral hamstring exercise that develops individual leg strength and addresses strength imbalances between legs. This movement is ideal for intermediate to advanced exercisers, athletes, and those seeking targeted hamstring development and injury prevention. The single-leg variation increases demands on stability and forces each leg to work independently, preventing stronger legs from dominating.
NASM's evidence-based approach recognizes unilateral training as essential for identifying asymmetries and building balanced development. The single-leg lying leg curl improves hamstring strength, corrects strength imbalances, develops muscular endurance, and supports injury prevention.
How to Perform A Lying Leg Curl Single Leg
Step 1: Setup
Lie face down on the leg curl machine with one leg extended and the other positioned under the pad just above the ankle.
Step 2: Brace/Position
Position one leg under the pad with your knee bent at approximately 90 degrees. Engage your core and maintain a stable torso throughout the movement.
Step 3: Execute/Drive
Curl the pad upward by flexing your hamstring, bringing your heel toward your glute while maintaining controlled movement and stability.
Step 4: Return/Descent
Extend your leg to return to the starting position with control. Complete all repetitions on one leg before switching to the other leg for balanced development.
Muscles Worked
Primary Muscles:
- Hamstring Group -- primary mover for knee flexion and single-leg hamstring curling
Secondary Muscles:
- Gastrocnemius
- Calf Muscles
- Core Stabilizers
Common Mistakes
- Using excessive weight that compromises form or causes jerky movements
- Allowing the torso to rotate or shift during the movement
- Not achieving full range of motion, which limits hamstring activation
- Jerky or uncontrolled movements reducing time under tension
- Failing to perform bilateral work before recognizing strength imbalances
Variations & Progresssions
As part of NASM’s evidence-based approach to movement and strength training, the barbell deadlift reinforces proper movement mechanics essential to long-term performance and injury prevention. NASM-certified personal trainers use the Optimum Performance Training (OPT) model to integrate exercises like the barbell deadlift into individualized programs based on each client’s assessment results.
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FAQs
What weight should be used for single-leg leg curls relative to bilateral curls?
Single-leg loads should be approximately 40-60% of your bilateral leg curl weight. This ensures adequate challenge while maintaining proper form and preventing compensatory movement patterns.
How does single-leg training help correct strength imbalances?
Single-leg training allows weaker legs to receive focused attention and develop strength independently. Over time, consistent unilateral training allows weaker sides to catch up, promoting balanced bilateral strength development.
How many repetitions should be performed for single-leg hamstring work?
Perform 3 sets of 8-12 repetitions per leg for hypertrophy and strength, or 3 sets of 12-15 repetitions for muscular endurance. Ensure equal volume on both legs to promote balanced development.