The overhand-grip rear lateral raise strengthens the shoulder and upper back with an emphasis on the rear deltoids.
Grab a pair of dumbbells and stand with your arms hanging straight down and palms facing behind you. Slightly bend your knees and torso until your upper body is nearly parallel to the floor.
Maintaining a slight bend in your elbows, raise your arms up, and directly out to the sides of your body until they are parallel with the floor. Pause, and then slowly lower the weights back to the starting position.
Keep your back flat and chest lifted. Do not arch your lower back during the movement.
Use the shoulders to initiate the movement. Do not sway your upper body to help with the lift.
Keep your head in line with your spine at all time.