This movement is performed with a dumbbell in a seated position.
Sit on a bench, leaving enough room to place your arms on. Bend forward
slightly.
Grasp the dumbbell with an underhand grip. Your forearm should be on the bench, with
your wrist over the edge of the bench. Curl the dumbbell upwards, contracting the
inner forearm muscles.
Slowly lower the weight back to a fully extended position. Repeat the movement.
Tips
For more advanced members, you can let the weight roll off your fingers slightly at
the bottom of the movement. Rolling it back up will put more stress on the forearm
muscles.