Why does the front of my hip pinch when I pull my knee in?

Deep hip flexion can crowd the front of the hip joint, especially if your hip shape or tight tissue limits how far the thigh can travel. Back off to where the pinch disappears, let the knee drift slightly out toward the same-side shoulder, or hold behind the thigh, and have it checked if the pinch keeps coming back.

Should the other leg stay straight or bent?

Keeping it straight and flat on the floor adds a light stretch to the front of that hip, while bending it with the foot flat is gentler on the lower back. If the straight thigh keeps lifting off the floor, the hip flexors on that side are probably tight, and the Kneeling Hip Flexor Stretch targets them directly.

Does the knee to chest stretch help lower back pain?

It often feels good for general stiffness in the lower back, which is why it appears in so many home programs for back pain. Not every back problem tolerates bending forward, so stop if pain increases or spreads into your leg and get advice from a clinician.

How long should I hold the stretch?

Hold each side for about 30 seconds and repeat it two to four times, which follows general guidance for static stretching. Breathe slowly throughout and let the knee come a little closer on each exhale rather than pulling harder.

What is the difference between the single and double knee to chest stretch?

Hugging both knees rounds the lower back further and gives a stronger lower back stretch, but you lose the stretch on the front of the hip that the straight leg provides. The single-leg version also lets you work each side separately and is easier to control.

Lying Knee to Chest Stretch

What Is the Lying Knee to Chest Stretch?

Lying Knee to Chest Stretch is an isolation exercise that primarily targets the glutes and also stretches the hamstrings and lower back. It is a beginner-level movement done lying on your back, hugging one knee toward your chest while the other leg stays long on the floor.

This is one of the simplest ways to stretch the back of the hip. Because you lie on the floor and your hands control how far the knee comes in, it asks for no balance and very little hip mobility, which makes it a common choice for cooldowns after running or lower-body training, morning mobility routines and home programs for a stiff lower back. The single knee to chest stretch is also one of the classic flexion exercises physical therapists have long used in lower back programs.

Pulling the knee toward the chest flexes the hip, which lengthens the gluteus maximus most. The hamstrings get a lighter stretch than in a straight-leg stretch such as the Standing Hamstring Stretch, because bending the knee shortens them at the knee end. As the knee comes in, the pelvis tilts back and the lower back flattens into the floor, so many people also feel a gentle stretch across the lower back. Keeping the other leg straight and flat on the floor adds a light stretch to the front of that hip. This is the same position therapists use in the Thomas test to check hip flexor length, so a thigh that lifts off the floor is a sign that side's hip flexors are short.

The stretch is easy to scale. Bending the bottom knee and setting that foot flat on the floor takes tension off the front of the hip and the lower back. Adding hip rotation, as in the Lying Figure Four Stretch, shifts the work toward the deeper hip rotators. It suits beginners, older adults and anyone who spends long hours sitting, and anyone who cannot comfortably hug the shin can hold behind the thigh or loop a towel around it instead.

Muscles Worked

MuscleActivation

Gluteus Maximus: Primary
Biceps Femoris: Medium
Semimembranosus: Medium
Semitendinosus: Medium
Adductor Magnus: Low
Erector Spinae: Low
Thoracolumbar Fascia: Low
Gluteus Medius: Minimal

Instructions

Lie on your back on the floor with both legs straight and your arms by your sides.
Bend your right knee and draw it up toward your chest.
Clasp both hands around the top of your right shin, just below the knee.
Keep your left leg straight and resting on the floor, with the heel down and toes pointing up.
Rest your head and shoulders on the floor and relax your neck.
Gently pull the knee toward your chest until you feel a stretch in your right glute and lower back.
Hold for about 30 seconds, breathing slowly and letting the knee come a little closer on each exhale.
Release slowly, lower your right leg to the floor and repeat on the left side.

Common Mistakes

Lifting the head
Curling the head and shoulders up to meet the knee strains the neck and turns the stretch into a crunch.
Gripping over the kneecap
Pulling directly on the kneecap presses the knee joint, so clasp the top of the shin or hold behind the thigh instead.
Letting the other leg drift
Allowing the straight leg to bend or lift off the floor removes the stretch across the front of that hip.
Forcing the knee in
Yanking the knee past a mild, steady pull tends to cause pinching in the front of the hip or discomfort in the lower back.
Holding the breath
Holding your breath keeps the muscles tense, while slow exhales let the knee settle closer to the chest.
Bouncing or rushing
Pulsing the knee or letting go after a few seconds does not give the muscles time to relax into the stretch.

Injuries

Lying Knee to Chest Stretch is a low risk exercise when performed with proper technique. You lie fully supported on the floor, no load is involved and your own hands set the depth, so problems almost always come from pulling too hard rather than from the position itself.

The most common complaint is a pinching feeling in the crease at the front of the hip, which comes from the thigh crowding the front of the hip joint in deep flexion. Easing off and letting the knee drift slightly out toward the same-side shoulder usually clears it. Clasping over the top of the shin puts some pressure through the knee, so anyone with a sensitive knee should hold behind the thigh instead. Keeping the head and shoulders on the floor protects the neck.

To make the stretch easier, bend the bottom knee with that foot flat on the floor, hold behind the thigh, or use a towel looped around the thigh if you cannot reach. To go further into the hip, move on to the Lying Figure Four Stretch or the Happy Baby Pose.

Stop if you feel sharp pain in the hip or back, or if pain, numbness or tingling spreads down either leg. Not every lower back problem tolerates bending forward, so anyone recovering from a back injury should check with a clinician first. After about 20 weeks of pregnancy, lying flat on the back for long periods can lower blood pressure, so keep holds short or choose a stretch done on your side or in a seated position.

Overview

Primary Focus: Glutes
Equipment: Body weight
Modality: Stretching
Difficulty: Beginner

Alternative Exercises

Frequently Asked Questions

Q: Why does the front of my hip pinch when I pull my knee in?: Deep hip flexion can crowd the front of the hip joint, especially if your hip shape or tight tissue limits how far the thigh can travel. Back off to where the pinch disappears, let the knee drift slightly out toward the same-side shoulder, or hold behind the thigh, and have it checked if the pinch keeps coming back.
Q: Should the other leg stay straight or bent?: Keeping it straight and flat on the floor adds a light stretch to the front of that hip, while bending it with the foot flat is gentler on the lower back. If the straight thigh keeps lifting off the floor, the hip flexors on that side are probably tight, and the Kneeling Hip Flexor Stretch targets them directly.
Q: Does the knee to chest stretch help lower back pain?: It often feels good for general stiffness in the lower back, which is why it appears in so many home programs for back pain. Not every back problem tolerates bending forward, so stop if pain increases or spreads into your leg and get advice from a clinician.
Q: How long should I hold the stretch?: Hold each side for about 30 seconds and repeat it two to four times, which follows general guidance for static stretching. Breathe slowly throughout and let the knee come a little closer on each exhale rather than pulling harder.
Q: What is the difference between the single and double knee to chest stretch?: Hugging both knees rounds the lower back further and gives a stronger lower back stretch, but you lose the stretch on the front of the hip that the straight leg provides. The single-leg version also lets you work each side separately and is easier to control.