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  3. Exercises
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  5. Arms
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  7. Roll Ball Forearm Extensors

Exercise guide

Roll Ball Forearm Extensors

  • Beginner
  • Isolation
  • Timed hold
  • Lower arms
  • Upper arms

This isolation exercise targets the forearm extensors on the top of the arm, using a medicine ball against a wall to provide constant tension and improve wrist stability.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Roll Ball Forearm Extensors demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Forearms

Equipment

  • Medicine ball

Setup

  1. Stand facing a wall with a medicine ball held against it at shoulder height using one hand.
  2. Position your hand so the palm is facing down (pronated) and the fingers are pointing toward the ceiling.
  3. Keep a slight bend in your elbow and stand in a staggered stance for better balance.
  4. Apply enough pressure to the ball to keep it pinned against the wall without it slipping.

How to do it

  1. Exhale and roll the ball upward by extending your wrist, moving the back of your hand toward your forearm.
  2. Inhale and slowly roll the ball back down to the starting position by flexing the wrist.
  3. Maintain a controlled 2-1-2 tempo (2 seconds up, 1 second hold, 2 seconds down).
  4. Complete all repetitions on one arm before switching to the other side.

Form checklist

  • Keep your elbow and shoulder stationary; the movement should occur only at the wrist.
  • Maintain constant, firm pressure against the ball throughout the entire range of motion.
  • Ensure your forearm remains parallel to the floor or slightly angled up, not tucked against your body.
  • Avoid using your body weight or shoulder to push the ball up.

Pro tips

  • Focus on the 'burn' in the top of your forearm; this indicates the extensors are being properly isolated.
  • Spread your fingers wide on the ball to increase the surface area and improve control during the roll.

Make it harder

  • Increase the weight of the medicine ball to add more resistance.
  • Perform the exercise with a fully extended arm to increase the stability demand on the shoulder.

Frequently asked

What muscles does the roll ball forearm extensors work?
The roll ball forearm extensors primarily targets the forearms.
What equipment do you need for the roll ball forearm extensors?
The roll ball forearm extensors uses medicine ball.
Is the roll ball forearm extensors good for beginners?
Yes. The roll ball forearm extensors is a beginner-friendly movement and a strong foundation to build on.

Related exercises

  • Band Wrist CurlBeginner · forearms
  • Barbell Behind Back Finger CurlBeginner · forearms
  • Barbell Palms Down Wrist Curl Over A BenchIntermediate · forearms
  • Barbell Palms Up Wrist Curl Over A BenchBeginner · forearms

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

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