# Kneeling Single Hamstring Curl - Canonical: https://fitwill.app/exercise/8934/kneeling-single-hamstring-curl/ - Media ID: 8934 - Primary muscle: Hamstrings - Body part: Thighs - Equipment: Body Weight - Video: https://fitwill.app/videos/8934/kneeling-single-hamstring-curl.mp4 ## Description The Kneeling Single Hamstring Curl is a bodyweight isolation movement performed from a hands-and-knees position, where one knee stays grounded for support while the other leg bends to pull the heel in toward the glute. Because you are working one leg at a time with no external load, the exercise isolates knee flexion almost entirely, letting you feel each hamstring contract without the lower back or hips taking over. It is essentially a manual, equipment-free hamstring curl that you can do anywhere. The main muscle at work is the hamstring group on the back of the thigh, particularly the biceps femoris on the outer portion, along with the semitendinosus and semimembranosus. The glutes help hold the lifted leg at hip height, and the core works to keep your torso from twisting as the free leg moves. This makes it a surprisingly demanding exercise despite using no weight. This movement suits beginners who are learning to feel their hamstrings, lifters who want extra hamstring volume without machines, and people rehabilitating or strengthening their legs at home. It also works well as a burnout or activation exercise before heavier leg curls, deadlifts, or hinge patterns. Because each side is trained independently, it helps expose and correct left-to-right strength differences that a two-legged machine curl can hide. Setup matters more than it looks. The grounded knee and both hands form your tripod of support, and the free leg should extend behind you at roughly hip height before the curl begins. If your hips sag, rotate, or shift sideways as you bend the knee, the hamstring loses tension and the movement loses its point. Keep the curl slow and deliberate: pull the heel toward the glute by squeezing the back of the thigh, pause briefly, then lower the leg back to full extension under control. A padded surface or folded mat under the grounded knee makes longer sets far more comfortable. If you find the exercise too easy at bodyweight, slow the lowering phase to three or four seconds or add more reps per side rather than rushing. If your hips cramp or the front of the thigh takes over, reduce the range slightly and focus on driving the movement from the back of the leg. Stop if you feel any pinching behind the knee, and keep the effort within a range you can control throughout. ## Instructions 1. Place an exercise mat on the floor and kneel on your right knee with your left foot planted, then place both palms flat on the floor directly under your shoulders so you are on hands and one knee. 2. Extend your left leg straight back behind you so it hovers at about hip height, with the toes pointed and the thigh roughly level with your torso; this is the working position. 3. Brace your core and tighten the glute of the working leg to lock your pelvis in place before the rep starts. 4. Keeping your hips square to the floor and your torso still, bend your left knee to curl your heel in toward your glute. 5. Squeeze the hamstring hard at the top, when the heel is as close to the glute as your range allows. 6. Lower the leg under control back to the extended starting position, resisting gravity rather than letting the leg drop. 7. Exhale as you curl the heel up, and inhale as you extend the leg back down. 8. Complete all reps on the left leg, then switch sides so your left knee is grounded and your right leg works. 9. Between sets, stand up and shake out the legs to release tension in the hips and hamstrings before your next set. ## Tips & Tricks - If your hips twist toward the working leg, think about pressing the grounded knee straight down into the mat and keeping both hip bones facing the floor. - Do not let the working leg drift upward as you curl; hold it at hip height so the hamstring does the flexing instead of momentum. - A common mistake is curling only halfway and rushing the return. Extend the knee fully at the bottom of every rep so the hamstring is lengthened before the next contraction. - If your grounded kneecap aches, double up the mat or place the pad under the thigh rather than directly under the kneecap. - Squeeze the glute of the working leg throughout the set. This stabilizes the pelvis and stops the lower back from arching to help the leg. - Pointing the toes can increase hamstring recruitment slightly, but if you feel a cramp in the calf, relax the foot and let the knee do the work. - When the standard tempo feels easy, take three to four seconds on the lowering phase instead of adding reps quickly. - Keep your shoulders stacked over your wrists; letting your weight shift back onto the kneeling leg reduces stability and makes the torso harder to hold still. - Start with your weaker or tighter leg first and match the rep count with the other side to keep both hamstrings balanced. ## Frequently Asked Questions ### Which muscles does the Kneeling Single Hamstring Curl target? The hamstrings on the back of the working thigh are the primary movers, especially the biceps femoris. The glutes and core work isometrically to keep the pelvis and torso stable. ### Is the Kneeling Single Hamstring Curl good for beginners? Yes. Because it uses only bodyweight and a short range of motion, it is one of the simplest ways to learn what a hamstring contraction feels like before progressing to machine or weighted curls. ### Why does one knee need to stay on the floor during the Kneeling Single Hamstring Curl? The grounded knee, along with both hands, creates a stable three-point base. It isolates the free leg so the hamstring can flex the knee without your hips or lower back compensating. ### My hips rotate when I curl my leg. How do I fix this? Lighten the effort, reduce the curling range slightly, and consciously squeeze the glute of the grounded-knee side while keeping both hips facing the floor. Slowing the tempo also helps you catch the rotation early. ### Can I do the Kneeling Single Hamstring Curl without a mat? You can, but the grounded knee takes your full body weight on a hard floor, which becomes uncomfortable quickly. A folded towel or any soft padding under the knee is recommended. ### What can I substitute if the kneeling position bothers my knee? Try a standing single-leg hamstring curl where you hold a wall for balance, or a stability ball hamstring curl. Both train knee flexion without loading the kneecap. ### How does the Kneeling Single Hamstring Curl compare to a lying leg curl machine? Both flex the knee against resistance, but the bodyweight version trains one leg at a time with lighter load and greater stability demand. The machine lets you add heavier, progressive resistance, so they complement each other rather than replace one another. ### Why do I feel this more in my glutes than my hamstrings? You are likely lifting the extended leg too high before curling, which turns the movement into a hip extension. Keep the thigh at roughly hip height and focus purely on bending the knee to bring the heel toward the glute. ### How many reps and sets should I do? Two to three sets of 10 to 15 controlled reps per leg works well for strength and muscle endurance. Because the resistance is low, prioritize slow tempo and a full range over high rep counts. ### Is it safe to do this exercise every day? For most people, yes, since the load is light, but treat it like any strength exercise and allow at least a day of recovery between harder sessions. If you have a current knee or hamstring injury, check with a qualified professional before adding it to your routine.