Position your right foot flat on the floor beside a bench with your knee slightly bent. Position your left knee on the bench. Lean forward and position your left hand on the bench to support your upper body.
Pick up a dumbbell with your right hand, palm facing in. Position your upper arm parallel to the floor and bend your elbow at a 90-degree angle.
Keeping your upper arm stationary, slowly straighten your arm. Keep your arm close to your side.
Slowly bend your arm to lower the dumbbell back to the starting position.
Repeat for desired amount of reps on that arm then switch to the other arm