The seated side bend, sometimes called the beach stretch, is a mobility exercise for the sides of your trunk. Sitting upright with your hands behind your head and your elbows out, you bend your upper body slowly to one side and then the other. It moves the spine sideways and stretches from the waist up to the armpit. Side bending also appears in exercise programs for conditions that stiffen the spine, such as ankylosing spondylitis.

How to do the seated side bend

Sit tall on a firm chair with your feet flat on the floor, about hip width apart.
Put your hands behind your head with your elbows pointing out to the sides. Let the hands rest there without pulling.
Bend your upper body slowly to one side, so one elbow drops toward your hip and the other points up toward the ceiling.
Keep facing forward with both sides of your bottom on the seat. Your head goes with your trunk rather than tipping further on its own.
Pause for a breath, come back to upright, then bend to the other side.

What you should feel

A stretch along the side of your trunk on the side that lengthens, from the waist up toward the armpit.

Common mistakes

Pulling on your head with your hands. They only rest there.
Tipping the head over to the side while the trunk hardly moves.
Leaning forward or twisting instead of bending straight to the side.
Lifting your bottom off the seat on the long side.

How often

Many programs use 5 to 10 slow bends to each side with a short pause at the end of each, once or twice a day. Your physio will adjust this.

Stop and check with your physio if

Sharp or pinching pain in your back or side, or pain, numbness or tingling spreading into an arm or leg.
You feel dizzy, faint or unsteady. Stop and get medical advice the same day. If you faint, it does not settle within a few minutes of sitting still, or you cannot stand or walk steadily, call emergency services.
Things look double, your vision suddenly blurs or goes, your speech slurs or becomes muddled, swallowing becomes hard, your face or lips go numb, one side of your face droops or one side of your body goes weak or numb, you suddenly become so dizzy or unsteady that you fall or cannot stand or walk, your legs suddenly give way but you do not black out (a drop attack), or you get a sudden severe headache. Stop and call emergency services, even if it goes away.

From the clinic

In the video the head tilts a fair way with each bend. Keep your head in line with your trunk instead, so your spine does the bending and your neck stays out of it. If your shoulders do not like your hands behind your head, cross your arms over your chest, or let them hang and slide one hand toward the floor as you bend. The standing side bend stretch is the upright version, and the seated trunk rotation turns the spine from the same chair.

If you have osteoporosis or have broken a bone in your spine before, ask your physio before you bend to the end of your range, as side bending is often kept gentle then. The same applies if you have had a rib injury, or surgery on your back, ribs, chest, heart or shoulder, in recent months. The wide elbows stretch across the front of your chest and shoulders as well as your sides.

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.

Seated side bend