FOREARM CURL BEHIND THE BACK
Fix the carriage and insert the handle bar so that it is below your buttocks.
Grasp the bar shoulder-width behind the body. Stand with your feet hip-width apart, abdominal muscles are tense and the lower back is straight. Arms are almost completely stretched out, keep a small kink in the elbow to protect the joint.
Slowly bend your wrists upwards as far as possible. Then slowly back to the starting position.
Make this exercise slowly and without momentum!