Isometric hip flexion works the muscles at the front of your hip without moving the joint. Lying on your back with one hip and knee bent to about a right angle, you press the knee up into your hands while your hands hold it still. It is often given when a hip is too sore to exercise through movement.

How to do the isometric hip flexion

Lie on your back on a firm bed or mat with both legs straight and your arms by your sides.
Bend the hip and knee of the leg you are working until both are at about a right angle. Keep the knee in line with your hip.
Rest both hands on the front of the thigh, just above the knee.
Press the knee up toward your hands while your hands push back just as hard, so nothing moves. At the same time, push the heel of your straight leg gently down into the bed and keep your pelvis still.
Hold the press while you breathe steadily, then ease off slowly. Relax fully before the next one, and lower the leg when you finish the set.

What you should feel

Tightening at the front of the hip and top of the thigh on the bent leg, with some effort in the buttock of the straight leg as its heel presses down.

Common mistakes

Letting the knee creep closer to your chest as you press. The thigh stays where it started.
Arching your lower back or lifting the heel of the straight leg.
Holding your breath to push harder.
Starting with your hardest push. Build up from a gentle one.

How often

A common starting point is 5 to 10 presses on each side, held for 5 to 10 seconds each, once or twice a day, at a gentle to medium effort. Your physio will adjust this.

Stop and check with your physio if

Sharp pain or a pinch at the front of the hip or in the groin while you press.
Your lower back starts to ache during the holds.
Your calf or thigh becomes swollen, warm, tender, red or darker than usual, or has a throbbing or cramping pain that feels different from normal muscle ache. Stop and get medical advice the same day, as this can be a blood clot. If you are also short of breath or have chest pain, call emergency services.

From the clinic

Start with a gentle to medium effort and only build up while the hip stays comfortable. If you have high blood pressure, breathe steadily through every hold and never hold your breath. The voice guide ends by relaxing and bringing the knee in further. That part is not in the video, and it would take the hip past a right angle, so it is left out here.

If you have had a hip replacement, get the go-ahead from your surgeon or physio before you try isometric hip flexion. Letting the knee creep toward your chest during the press takes the hip past a right angle, and many surgeons ask you to avoid that for the first months after some operations. The start position already bends the hip to about a right angle, so if your limit is lower, your physio can show you how to press with the hip bent less. If you are pregnant and past the first three months, check with your physio before exercising flat on your back.

When holding still feels easy, supine marching works the front of the hip through movement.

Written and checked by the PocketPhysio editorial team. Last updated 2026-09-26.

This page is general education, not a diagnosis or a personal treatment plan. If you have pain, an injury or a health condition, see a physiotherapist or doctor before starting new exercises.

Isometric hip flexion