The sliding leg curl is a good, closed chain, hip dominant exercise that simultaneously works the muscles involved in knee flexion and hip extension, increases strength and improves coordination among the muscles of the posterior chain. This is a complex and extremely functional exercise when performed correctly in that it uses the glutes to stabilize the pelvis while the hamstrings work to assist with pelvic stabilization and control flexion and extension at the knee.
Sliding leg curls can be performed using either a slideboard or Valslide discs. Since slideboards are hard to pack and seldom available on the road, we prefer to use portable Valslide discs because they enable us to perform the exercise in the same manner both at home and on the road.
The starting position is a supine, bridged position with the feet and knees together; ankles dorsiflexed, heels on the Valslides and legs extended until the buttocks almost touch the ground. Next, set the abs, squeeze the glutes and perform a leg curl without flexing at the hips. Pause at the top, return to start and repeat. Keep the hips up throughout the exercise. Don’t let the butt sag as this takes glutes out of the exercise and severely diminishes the effectiveness of the exercise. Don’t extend the lumbar spine. Proper execution requires hip extension, not lumbar extension. The hip and hamstring actions in this exercise mimic those used in running, i.e., the glutes act as hip extensors while the hamstrings act as both synergists for hip extension and knee flexion.
When you can perform 2-3 sets of 6-8 reps with perfect form, progress to single-leg curls and then resisted double- and single-leg curls. To perform double-leg resisted curls, put a small plate on top of each Valslide and repeat the exercise. Start slow, adding as little as 5 pounds can significantly increase in the intensity of the exercise.
Note: some athletes, especially those with glute-firing issues, will not be able to switch from the eccentric to the concentric movement while maintaining glute contraction. In this case, the hips will drop and flex during the concentric movement. If this happens, perform eccentric only movements with a 5-second count down until strength and function are improved. Start with toes up and heels on the Valslides in double-leg bridge. Set the abs, squeeze the glutes and slowly slide out from the hip-flexed bridge position until the legs are out stretched. Relax, walk the feet back to the bridge position and repeat for 3-5 reps.
Brian Jordan, RSCC*D, is the Head Strength and Conditioning Coach for the Colorado Rockies.