A lying isometric triceps press works the muscle at the back of your upper arm (triceps) without the elbow moving. You lie on your back with a folded towel under your upper arm, bend the elbow to a right angle, and try to straighten it while your other hand holds the forearm still. Because the joint stays in one place, physios often use it early in elbow and arm rehab, when moving the elbow against a weight is still too sore or not yet allowed.

How to do the lying isometric triceps press

Lie on your back on a bed or mat with a pillow under your head. Put a folded towel under the upper arm you are working, just above the elbow.
Keep that upper arm resting beside your body and bend the elbow to a right angle, so your forearm points up at the ceiling. Keep the hand open and relaxed, with the fingers pointing up, as in the video.
Reach across your body with your other hand and hold the working forearm just below the wrist, with your palm on the side that faces your feet.
Try to straighten the elbow, as if pushing your fist down toward your feet, while the other hand blocks it so nothing moves. Build the push up over a second or two.
Hold the push steadily and keep breathing, then ease off slowly and let the arm relax before the next one.

What you should feel

Firm work in the back of your upper arm while the elbow stays still. The other arm and shoulder work a little too, just to hold the forearm in place.

Common mistakes

Pushing so hard that the elbow shakes or the forearm starts to move. A steady, moderate push is enough.
Holding your breath while the push is on.
Lifting the upper arm off the towel or shrugging the shoulder up toward your ear.
Releasing all at once when the hold ends, rather than easing off.

How often

Many programs use holds of 5 to 10 seconds, repeated 5 to 10 times, once or twice a day, at a moderate effort. Your physio will adjust this.

Stop and check with your physio if

Sharp pain at the elbow or in the back of the upper arm, or pain that builds while you hold.
Tingling, pins and needles or numbness in your hand, most often in the ring and little fingers (from the nerve behind the elbow, the ulnar nerve) or in the thumb, index and middle fingers (the median nerve).
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.

From the clinic

Start gently. About half your effort is plenty for the first few sessions, and you can push a little harder once the elbow is fine that day and the next morning. If you have high blood pressure, breathe steadily through every hold and never hold your breath. If your wrist is sore, move the resisting hand a little higher up the forearm so the push goes through the forearm rather than the wrist.

Keep the working hand open and relaxed rather than making a tight fist. A hard grip brings in the forearm muscles that start at the outer and inner elbow, which can stir up tennis elbow or golfer's elbow. After a broken or dislocated elbow, or elbow surgery such as a tendon repair, follow your surgeon's or physio's plan, and start this exercise only when they have cleared you. Pushing the elbow straight against resistance is often held back for several weeks after a break at the point of the elbow (olecranon) or a triceps tendon repair.

If you have just hurt your arm and have severe pain, cannot move the elbow or heard a snap, do not exercise it. Go to an urgent care center or emergency department the same day. If the arm looks a different shape or sits at an odd angle, a bone is showing, or your arm or hand tingles, feels numb or turns cold, pale or blue, go to an emergency department straight away or call emergency services, and do not drive yourself.

If you are pregnant and past the first three months, check with your physio before exercising flat on your back. The same push works sitting in a chair with the upper arm by your side. For triceps work that moves the elbow and takes your body weight, see triceps dips on a chair, which usually comes much later.

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.

Lying isometric triceps press