1 Arm Lateral Raise
Stand with your feet shoulder width apart, supporting your back with your un-weighted arm, in order to prevent any forward - backward or lateral side movement during the exercise.
Holding
a suitable dumbbell in your hand, smoothly lift the weight up from your side,
to a horizontal position out to your side, aiming to keep your arm straight,
hand inline with your shoulders.
Focus on keeping the upper body fixed by keeping your abdominal muscles contracted throughout the movement to avoid leaning forward or back during the lifting or lowering phase.
You may also decide to adjust your wrist position so that palms are facing downwards or forwards, working both arms at the same time, or simply alternating arms.