One Arm Bent Over Dumbbell Reverse Fly Video Exercise Guide

1. Set up for the exercise by grasping a dumbbell with a neutral grip (palm facing in) with your left hand and standing with your feet around shoulder width apart.
2. Bend slightly at the knees and bring your torso forward by bending at the waist.
3. Keep your head up and your eyes facing forward. 
4. Your elbow should be slightly bent and the dumbbell should be directly under your chest. You can rest your non-working forearm on your right knee for stability. This is the starting position.
5. Moving only at the shoulder, raise your left arm in a semi-circular motion out to your side until your arm is parallel to the floor. Keep the slight bend in your elbow throughout the movement.
6. Squeeze your shoulder blades at the height of the movement and then begin slowly lowering the dumbbell back to the starting position.  
7. Repeat for desired reps and then repeat with your right arm.

Exercise Tips:

1. Practice good form with a light weight.
2. Squeeze your shoulder blades and pause for a moment at the top of the movement.  
3. Do not let the dumbbells "hang" at the bottom of the movement, but keep the tension in your arms.
4. Focus on moving only at the shoulder. The rest of your body should be kept as still as possible and your arms should hold the same form throughout the movement.
5. It is usually wise to work your weakest arm first. For many people, this will be their left.