Build Stable Shoulders and a Strong Core With Single-Arm Planks

Take care of your shoulders with this simple exercise.

Athletes ask a lot of their shoulders. The shoulder joints must handle heavy lifting, facilitate explosive arm movements and absorb violent collisions, all while staying strong and pain free.

But the shoulder is an unforgiving joint. Thanks to its ball and socket structure, it is extremely mobile, but it relies on muscles, tendons and ligaments to provide support. And if one of those structures isn't properly supported, another will pick up the slack, increasing the risk of pain and injury.

Most of you have probably heard that strengthening the four rotator cuff muscles is important for shoulder health. While this is true, you can't forget about the muscles that move your scapulae (shoulder blades), which provide stability for your shoulder joints.

"If the shoulder blade itself isn't stable, all of the muscles that activate shoulder motion—lifting, swimming, different activities—will be compromised and put us at a greater risk for injury," asserts Dr. Matt Stevens, physical therapist and owner of Pure Physio (Strongsville, Ohio). "The greater stability we have in and around the shoulder blade, the better the shoulder muscles can work and activate, reducing the risk of injury in any of the ligaments, tendons and muscles of the shoulder joint."

This is especially important if you lift heavy weights, play a throwing or swinging sport/position, or you're a swimmer.

Beyond building a stronger back with exercises like Rows, Pull-Ups and Deadlifts, Stevens recommends performing the Single-Arm Plank to improve shoulder blade stability and help protect your shoulders. As a bonus, this improves core strength and activates your core muscles before a workout.

Instead of simply holding a Plank position, Stevens has his athletes reach one arm to three different cones to challenge their shoulders from multiple directions and develop the strength needed to handle intense athletic movements. 

Do this exercise 2-3 times per week during your warm-up. The arm raises increase in difficulty, so if you're new to the move, stick with the straight-ahead raise. Eventually, you should be able to get around the triangle of cone up to six times.

Here's how to perform the Single-Arm Plank.

Step 1: Set up three cones in a triangle about 3 feet apart from each other.

Step 2: Assume a high plank position with your hands under your shoulders between two cones in the triangle. Lock your elbows, and pull your shoulders down and back. Push your back away from the ground and tighten your core.

Single-Arm Plank Set-up

Step 3: Keeping your core tight and hips square to the ground, lift your right arm and reach toward the cone in front of you. Briefly hold and return to the starting position.

Single-Arm Plank

Step 4: Repeat Step 3, but reach to the cone on your right.

Single-Arm Plank

Step 5: Again, repeat Set 3, but reach under your body to the cone on your left.

Single-Arm Plank

Sets/Reps: 3-4x4-6 for each arm. Rest as needed.