The side lying quad stretch is done on your side: you hold the ankle of your top leg and draw the heel toward your buttock to stretch the front of the thigh (quadriceps). Lying down takes balance out of it, so it suits people who find the standing version hard to hold.

How to do the side lying quad stretch

Lie on your side on a mat with the leg you want to stretch on top. Your head can rest on your lower arm or on a pillow.
Keep your bottom leg straight and in line with your body. If your lower back arches or you roll about, bend the bottom knee forward in front of you instead to steady your pelvis.
Bend your top knee and reach back with your top hand to hold the front of that ankle. If you cannot reach, loop a towel or belt around the ankle and hold the ends.
Gently draw the heel toward your buttock, then ease the top knee back a little until you feel a stretch down the front of the thigh. Keep that knee at about the level of your hip, not lifted toward the ceiling, and do not arch your back.
Hold the stretch and breathe easily, then let go slowly and turn over to stretch the other leg if needed.

What you should feel

A steady pull down the front of the thigh, sometimes up into the front of the hip. Nothing sharp in the knee or lower back.

Common mistakes

Arching your lower back to take the knee further back.
Letting the top knee float up toward the ceiling.
Yanking the heel in, or bouncing at the end of the stretch.
Rolling back onto your back as you reach for the ankle.

How often

A typical plan is 2 or 3 holds of 20 to 30 seconds each side, done daily or twice daily. Your physio will adjust this.

Stop and check with your physio if

Sharp or pinching pain in the knee, or pain in your lower back.
Pins and needles or numbness running into your thigh, shin or foot.
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

Using a towel or belt is not cheating. Plenty of people cannot reach the ankle comfortably on their side. Twisting round to grab it strains the back and shoulder, while a strap lets you keep the pull slow and even. If lying on your side does not suit you, the prone quad stretch and the standing quad stretch stretch the same muscles.

After a knee fracture or knee surgery, including a knee replacement, follow your surgeon's or physio's plan, and start this exercise only when they have cleared you. Pulling the heel in bends the knee a long way, so ask how far yours may bend at your stage. If you have had a hip replacement, get the go-ahead from your surgeon or physio before you try the side lying quad stretch. Easing the top knee back takes the hip behind the line of your body, and many surgeons ask you to avoid that for the first months after some operations. Some operations also limit letting the top knee drop across your body toward the floor, so keep it level with your hip.

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.

Side lying quad stretch