Why the Hamstrings Need Direct Work
The deadlift and Romanian deadlift work the hamstrings heavily, but primarily as a hip extensor — the muscle is working to extend the hip, not flex the knee. The lying leg curl works the hamstrings as a knee flexor, which is the other primary function of the muscle. Training a muscle through both its functions produces more complete development and, critically, better injury resistance. Hamstring strains are one of the most common injuries in sport and in recreational training. Direct leg curl work addresses that weakness directly.
How to Perform It
Lie face down on the machine with the pad resting just above the heel, on the lower calf. The knees should be just at or slightly beyond the edge of the pad. Hold the handles lightly for stability — do not pull on them. From the starting position with legs straight, curl the heels toward the glutes as far as the machine allows. Hold briefly at the top, then lower slowly under control back to the starting position. The hips should remain pressed into the pad throughout — if they are rising, the weight is too heavy or the range of motion is being cheated.
Common Mistakes
The first mistake is allowing the hips to rise off the pad as the weight increases. This brings the lower back into the movement and removes the work from the hamstrings. Keep the hips pressed down throughout. Second: not achieving a full range of motion. Curl fully — the hamstrings should be fully contracted at the top — and lower fully. Partial reps through a limited range produce limited results. Third: rushing. The lying leg curl responds particularly well to a slow eccentric phase. Lower the weight over three seconds.
Hamstrings and Knee Health
The hamstrings cross both the hip and the knee joint. Their role in stabilising the knee — particularly in preventing anterior displacement of the tibia — is well established in sports science. Weak hamstrings are consistently identified as a risk factor for knee ligament injuries, particularly ACL (anterior cruciate ligament) injuries. Strengthening the hamstrings through the full range of the lying leg curl is therefore not just about aesthetics — it is directly relevant to long-term joint health.
Programming
Three to four sets of ten to fifteen repetitions. Like the leg extension, this is an accessory exercise that follows the compound work. Pair it with the leg extension for a complete quad and hamstring isolation protocol at the end of a leg session. Rest sixty to ninety seconds between sets.
