Seated Leg Curl

The Seated Leg Curl is a machine-based hamstring isolation exercise that develops posterior chain strength and muscular endurance while providing a safe, stable training environment. This exercise is ideal for all fitness levels and those seeking targeted hamstring development, injury prevention, and knee health. The seated position provides back support and stability while allowing substantial hamstring isolation and strength development.

NASM’sevidence-based approach recognizes machine-based leg curls as effective for isolating hamstring muscles and building balanced leg development. The seated leg curl improves hamstring strength, develops muscular endurance, supports knee health, and translates to improved pulling strength and functional leg capability.

How to Perform a Seated Leg Curl

Step 1: Setup

Sit on the leg curl machine with your back firmly against the backrest. Adjust the seat so the pad sits just above your ankles and position your feet on the platform.

Step 2: Brace/Position

Position both legs under the pad with your knees bent at approximately 90 degrees. Engage your core and position your hands on the machine for stability and support.

Step 3: Execute/Drive

Curl the pad downward by flexing your hamstrings, bringing your heels toward your glutes while maintaining controlled movement. Focus on hamstring contraction throughout the exercise.

Step 4: Return/Descent

Extend your legs to return to the starting position with control, maintaining tension in the hamstrings. Stop just short of full extension to maintain continuous muscular tension throughout the set.

Muscles Worked

Primary Muscles:

• Hamstring Group (Biceps Femoris, Semitendinosus, Semimembranosus) -- primary mover for knee flexion and hamstring curling motion

Secondary Muscles:

• Gastrocnemius
• Calf Muscles

Common Mistakes

• Using excessive weight that causes jerky movements or compromises form
• Not achieving full range of motion, which limits hamstring activation and development
• Jerky or uncontrolled movement, which reduces time under tension and effectiveness
• Moving too quickly without controlling both concentric and eccentric phases equally
• Allowing the hips to shift or rotate during the movement

Seated Leg Curl Variations

• Lying Leg Curl
• Lying Leg Curl Single Leg
• Single-Leg Seated Leg Curl
• Romanian Deadlift Barbell

As part of NASM's evidence-based approach to movement and strength training, the seated leg curl 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 seated leg curl into individualized programs based on each client's assessment results.

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