In side lying shoulder flexion you lie on your good side and swing your straight top arm forward, from your hip around toward your head. Lying on your side means the arm travels level with the floor instead of lifting against its own weight, so it asks less of the shoulder than raising the arm while standing. Physios often use it when a shoulder is stiff or weak and lifting the arm upright is still hard.

How to do the side lying shoulder flexion

Lie on your good side and bend your hips and knees so you do not tip over. Fold your bottom arm under your head as a pillow, or use a real one.
Rest the top arm along your side with the elbow straight and the hand near your hip.
Keeping the elbow straight, move the arm forward past the front of your chest. It stays at about the height of your shoulder, gliding level with the floor rather than rising toward the ceiling.
Carry on around toward your head as far as is comfortable. In the video the arm keeps going until it points past the top of the head, close to in line with the body.
Bring the arm back along the same path with control until it rests on your side again, then repeat.

What you should feel

Light work at the front of the top shoulder and along the side of the ribs, with perhaps a mild stretch near the end of the reach. Nothing sharp.

Common mistakes

Bending the elbow to make the arm lighter.
Rolling forward or back with the arm. Your top hip and shoulder should stay over the bottom ones.
Letting the arm sink down onto the mat in front of you instead of keeping it level with the shoulder.
Letting the top shoulder creep up toward your ear.

How often

Many programs start with 1 to 3 sets of 10 slow swings, once or twice a day, going a little further only while it stays comfortable. Your physio will adjust this.

Stop and check with your physio if

A sharp pain or a catch in the shoulder as the arm moves forward or toward your head.
Pain, pins and needles or numbness spreading down your arm or into your hand.
Pins and needles in your arm or hand that do not go away after you stop, or part of your arm or hand goes numb. Get medical advice the same day. If one side of your face or body suddenly goes numb or weak, or your speech becomes slurred or muddled, call emergency services, even if it goes away.
A sudden pop or tearing feeling in the shoulder that brings sharp pain, new weakness or trouble lifting the arm. Stop and contact your surgical team the same day, or get medical advice the same day if you have not had surgery.
The shoulder feels as if it has slipped out of place, looks a different shape or suddenly locks so you cannot move the arm, or your hand turns cold, pale or blue. Go to an emergency department straight away, without driving yourself, and do not try to put the shoulder back in yourself.

From the clinic

If holding the arm up is tiring, lay a long pillow along the front of your body and let the arm slide over it. The movement then takes even less effort. When the swing feels easy, programs often go on to lifting the arm forward with help from the other hand, as in shoulder flexion with a stick, and later to wall slides facing a wall.

After shoulder surgery, including a rotator cuff repair, or after a shoulder fracture or dislocation, follow your surgeon's or physio's plan, and do only the movements and range they have cleared. Many plans allow only passive movement at first, where the arm is moved for you and its muscles stay relaxed. Here your own muscles move the arm. That stage usually comes after the passive and assisted ones, so check it is on your plan before you start.

If you have had a hip replacement, get the go-ahead from your surgeon or physio before you try side lying shoulder flexion. Lying on your side lets the top leg slide forward or drop across the lower one, and many surgeons ask you to avoid that for the first months after some operations. A pillow between your knees helps keep the legs apart.

Written and checked by the PocketPhysio editorial team. Last updated 2026-09-28.

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 shoulder flexion