Seated Leg Curl
The seated leg curl performs the same knee flexion pattern as the lying leg curl but from a seated position with the hip at approximately 90° flexion. This hip angle pre-stretches the hamstrings at their proximal (ischial) attachment before the knee flexion movement begins, placing all three heads in a more lengthened position throughout the range. The seated variation is preferred for hypertrophy applications based on the evidence for lengthened-position training advantages.
Execution
- Sit in the machine with the back pad adjusted so the knees align with the machine's pivot point
- Place the ankle pad just above the heels; secure the thigh pad firmly to prevent hip lifting
- Curl the legs downward and back toward the seat as far as the machine allows
- Hold briefly at the contracted position, then return under control
What the EMG Data Shows
Ebben 2009 (seated, hip 90°): 80.8% ± 28% MVIC for the hamstrings overall. The large SD (28%) reflects individual differences in machine fit and hip angle maintenance.
Why the Seated Version Is Mechanically Preferable
The hip angle at 90° creates two advantages:
Proximal pre-stretch: The hamstrings originate at the ischial tuberosity. When the hip is flexed 90°, this origin point moves further from the distal attachment (tibia), elongating the muscle before any active contraction.
Lengthened-position hypertrophy: Research consistently shows greater muscle growth when exercises load the target muscle at longer lengths.
Seated vs Lying
| Feature | Lying | Seated |
|---|---|---|
| Hip angle | 0° | 90° |
| Hamstring length | Mid-range | Lengthened |
| Preferred for | Bilateral symmetry check | Hypertrophy |
If only one curl variation is included in a program, the seated version is the first choice based on current evidence.
For system-specific training applications, see each system's lens entry.