Single-Arm Overhead Carry
The single-arm overhead carry is a simple but effective overhead stability exercise.
Position a dumbbell, kettlebell or similar overhead in one hand. Lock the position in well with a retracted shoulder blade, extended upper back, and complete trunk tension, and keep the elbow extended forcefully. Keep the palm facing forward as it would be if holding a barbell overhead. Walk the prescribed distance and switch sides. The goal is to reduce movement of the arm as much as possible.
The single-arm overhead carry is a simple exercise for improving overhead stability and shoulder stability generally. By removing the support and potential compensation gained through a barbell held in two hands, it forces each shoulder to develop stability equally and will improve mobility to a certain extent as that stability and strength improves.
The single-arm overhead carry should be done near the end of training sessions after any significant overhead work has been completed. 2-4 sets of 50-100 m per arm is a good prescription. Weight should be challenging but needs to allow a stable, locked-out position or the exercise is not serving its purpose.
The single-arm overhead carry can of course be loaded with yust about anything—dumbbells and kettlebells are the easiest and most obvious, but plates, sandbags, medicine balls and more can be used. Kettlebells can also be carried in the bottom-up position, and plates can be held vertically.