# Lying Supine Heel Slide - Canonical: https://fitwill.app/exercise/9969/lying-supine-heel-slide/ - Media ID: 9969 - Primary muscle: Quads - Body part: Legs - Equipment: Exercise Mat - Video: https://fitwill.app/videos/9969/lying-supine-heel-slide.mp4 ## Description The Lying Supine Heel Slide is a low-load floor exercise performed on your back, where you draw one heel along the ground toward your hips by bending the knee, then slide it back down to full extension. Because the heel stays in contact with the floor the entire time, the leg supports its own weight and the joint moves through a controlled, friction-managed arc. The highlighted musculature in this movement is the quadriceps at the front of the thigh, which lengthens as the knee bends and shortens as the leg returns to straight. This exercise is a staple in knee and hip rehabilitation settings, and it carries over well to general training as a warm-up or mobility primer. People recovering from knee stiffness, returning from periods of immobilization, or managing tight quadriceps and hip flexors benefit most from it. It is also useful for desk workers and runners whose hips sit in a shortened position for long hours, since the supine position lets the hip extend fully while the knee flexes. The Lying Supine Heel Slide primarily trains active knee flexion and extension range of motion while the quadriceps control the leg the whole way. The deep core and lower abs work isometrically to keep the pelvis neutral and the lower back settled against the mat. The hip flexors on the working leg also lengthen and load gently as the heel travels toward the hip, which is why the movement feels productive through both the thigh and the front of the hip. Setup matters because everything about this drill is positional. Lying flat with the non-working leg extended anchors the pelvis; if the torso or hips twist, the knee drifts inward or outward and the intended thigh path is lost. Keeping the heel glued to the mat turns the floor into a guide rail, which removes momentum and forces the muscles around the knee, not gravity or momentum, to produce the motion. To execute well, lie on your back with both legs long and arms resting at your sides. Brace the trunk lightly, then slide one heel toward your sitting bone by bending the knee, keeping the kneecap pointed at the ceiling. Pause briefly near the top of your comfortable range, then reverse the slide until the leg returns to full extension. Breathe steadily throughout and let the heel speed stay constant in both directions. Common use cases include post-injury or post-surgery knee range restoration, pre-run lower body preparation, gentle quad and hip flexor lengthening on recovery days, and rebuilding confidence in a knee after a flare-up. Stop short of forcing the heel higher than the knee comfortably allows; range improves with consistent, pain-free repetitions rather than aggressive pushing, and any sharp pain in the knee or hip is a cue to reduce the range or check your setup. ## Instructions 1. Lie flat on your back on an exercise mat with both legs fully extended and arms relaxed at your sides, palms facing down. 2. Point the kneecap of your working leg straight up toward the ceiling so the thigh is neither rotated inward nor outward. 3. Gently brace your abdominals and press your lower back toward the mat to set a neutral pelvis before moving. 4. Exhale slowly as you bend the working knee and slide your heel along the mat toward your hip. 5. Keep the heel in constant contact with the floor and the knee tracking in line with the hip throughout the slide. 6. Stop when the knee reaches a comfortable bent position, typically with the heel close to your sitting bone, and hold for one or two seconds without letting the pelvis tilt. 7. Inhale as you slowly straighten the knee, sliding the heel back down the mat under control until the leg returns to full extension. 8. Complete all repetitions on one leg, then switch sides, or alternate legs rep by rep if that feels more natural. 9. Reset your trunk position between reps if you feel your lower back arch or your hips shift on the mat. ## Tips & Tricks - The most common mistake is letting the knee fall inward or outward as the heel rises; cue the kneecap toward the ceiling to keep the thigh in a straight line with the hip. - If your lower back lifts off the mat as the heel approaches your hip, slide the heel only as far as the pelvis stays quiet, and gradually extend the range over sessions. - A tendency to yank the heel up quickly usually means the range is being chased instead of controlled; slow the slide so the up phase takes two to three full seconds. - Wearing smooth pants or sliding the heel on a mat rather than bare skin on carpet reduces friction so the knee, not the drag, sets the difficulty. - If the top of the thigh cramps as the knee bends, shorten the range slightly and relax the quad deliberately between reps; cramping often eases as the muscle adapts to lengthening under load. - Pressing the non-working heel or toes into the floor gives the pelvis a stable reference point and stops the body from rotating toward the moving leg. - Keep the foot relaxed rather than pointing or flexing hard; extra ankle tension often sneaks into the thigh and changes how the knee tracks. - Breathe out on the slide up and in on the way down instead of holding your breath; breath-holding raises trunk tension and makes the pelvis stiff in the wrong way. ## Frequently Asked Questions ### What muscles does the Lying Supine Heel Slide work? The quadriceps on the front of the thigh are the primary muscles, lengthening as the knee bends and shortening as it straightens. The hamstrings and hip flexors assist the movement, while the lower abs stabilize the pelvis isometrically. ### Is the Lying Supine Heel Slide suitable for beginners? Yes, it is one of the most accessible lower body drills because the floor supports the leg and the heel contact limits the range naturally. Beginners should simply stay within a pain-free arc and let range improve gradually. ### Why does my heel need to stay on the floor during the Lying Supine Heel Slide? Keeping the heel in contact with the mat removes momentum and turns the floor into a guide for the knee's path. It also lets you regulate the range precisely by controlling how far the heel travels. ### How far should I slide my heel toward my hip? Slide only as far as the knee bends comfortably without pain and without your lower back arching or pelvis tilting. For most people this places the heel near the sitting bone, but the exact distance matters less than clean tracking. ### Can I do the Lying Supine Heel Slide with both legs at once? Yes, sliding both heels together is a common variation, though it demands more from the trunk to keep the lower back settled. Most people find alternating legs easier to control when starting out. ### What is the most common mistake in this exercise? Letting the knee drift inward or outward as the heel rises, which changes the thigh's path and can irritate the joint. Keeping the kneecap pointed at the ceiling corrects this immediately. ### What can I use instead of a mat for the Lying Supine Heel Slide? Any smooth, firm surface works, such as a bed, a towel on a smooth floor, or a sliding disc under the heel. The key is that the heel moves freely while the knee stays aligned. ### Is it safe to do this exercise after a knee injury? It is frequently used in knee rehabilitation because of its low load, but you should follow the specific range and progression guidance given by your physical therapist or doctor. Never push into sharp pain, swelling, or catching in the joint. ### How many repetitions of the Lying Supine Heel Slide should I do? Ten to fifteen slow, controlled repetitions per side is a solid starting dose, whether used as rehab, warm-up, or mobility work. Quality of the slide matters far more than total volume.