Mobility for Throwing Athletes

Mobility Training for Throwing Athletes: The Shoulder, the Scapula, and the Rest of the Throw

I’ve said for a long time that the body was built to throw. Long before anyone squatted a barbell, humans picked things up and launched them, and the throwing motion is still one of the most demanding things a body can do. In a fraction of a second, force travels from the ground up through the trunk and out the arm, which whips through a range most people never touch.

So it’s no surprise that throwers’ shoulders end up different from everyone else’s. Baseball and softball players, quarterbacks, volleyball hitters, and tennis players all build a dominant shoulder that moves differently from the other one. Part of that change helps them throw, and part of it can become the setup for pain, so most of the work is knowing which is which.

What throwing asks of the shoulder

In the cocking phase, just before the arm comes forward, the throwing shoulder rotates externally to an extreme position. The forearm lays back well past what you could reach standing still, with the scapula and thoracic spine contributing a good share of that apparent range. Then the arm accelerates forward and internally rotates at some of the fastest joint speeds measured in sport.

After the ball leaves, the job flips. Everything that just sped up has to slow down, and the muscles at the back of the shoulder and around the scapula absorb that load eccentrically, lengthening while they work. Deceleration is where a lot of the stress on the shoulder lives, and it gets less attention than the acceleration because it’s harder to see.

Repeated thousands of times a season, that cycle changes the joint.

Adaptation versus loss of range

Most throwers gain external rotation in their throwing shoulder and lose some internal rotation. Part of that is bone. Throwers who start young can develop a humerus that sits with more built-in twist, which shifts the whole arc of rotation toward external rotation. The soft tissue at the back of the shoulder also tends to stiffen with years of repeated deceleration, and that stiffness is the part training can change.

If the arc has simply shifted, and total rotation (internal plus external) matches the other shoulder, the joint has adapted to the sport and there’s nothing to fix. The research has focused on what happens when total rotation drops.

In professional pitchers, those with a total rotational motion deficit greater than five degrees compared with their non-throwing shoulder had a higher rate of injury. Pitchers with a large internal rotation deficit alone were nearly twice as likely to be injured, though that finding didn’t reach statistical significance (1). In high school softball and baseball players, losing 25 degrees or more of internal rotation on the dominant side was associated with four times the risk of an upper extremity injury (2).

I’d hold those numbers loosely. They come from specific populations, measured specific ways, and range of motion is one input among many. But they point at the same practical idea. The question to ask about a thrower’s shoulder is how the total compares to the other side, and how much of that range the athlete controls.

The scapula during deceleration

The scapula is the base the shoulder works from. When the arm decelerates, the scapula has to move with it and stay positioned so the joint surfaces line up and the muscles at the back of the shoulder can do their job.

When scapular movement is off, the shoulder tends to work from a worse position. A consensus statement from shoulder researchers found that altered scapular movement shows up in a high percentage of shoulder injuries, while also noting that its exact role in causing those problems isn’t clearly defined (3). I appreciate that honesty, and it’s how I’d frame it with an athlete: the scapula is worth assessing and training, and it’s rarely the whole story.

We’ve written about training the scapula for healthier shoulders in more general terms. For throwers, the emphasis shifts toward control at speed and under eccentric load.

The arm is the last link

A good throw starts at the ground, with the legs and hips generating force that the trunk transfers up through the shoulder and into the arm. When the lower body or trunk doesn’t contribute its share, the arm tends to make up the difference, and the shoulder and elbow absorb load they weren’t built to produce on their own.

That’s why throwers with a restricted hip or a stiff thoracic spine often show up with a shoulder complaint. The rotational strength work covers the trunk and hip side of this in depth, and coiling core training speaks to how the spine sequences rotation. This piece stays on the shoulder, with the understanding that the rest of the chain has to be moving well for any of it to hold.

Training the throwing shoulder

The goal is range the athlete can produce and control, on both sides of the rotational arc. A few pieces we lean on:

Shoulder CARs work as a daily check. Slow, full-range rotations of the shoulder tell the athlete how the joint feels that day, and comparing sides over a season shows if the throwing arm is losing range. This free shoulder external rotation class is a good place to start feeling what controlled rotation means.

PAILs and RAILs handle internal and external rotation. Taking the shoulder toward the end of its range and then contracting into and out of that position builds strength where the throw needs it. Our guide to PAILs and RAILs explains the structure. From what I’ve seen, this works better for internal rotation than forcing range passively, because the athlete builds control in the range they gain.

Scapular control drills start with moving the shoulder blade through its full range and holding position under load, then progress toward speed and eccentric demands as the athlete improves.

Volume has to be managed in season. The amount of range work a thrower can handle drops when the throwing load is high. In season, the work tends to shrink to short daily maintenance, with the heavier end-range training saved for the offseason.

One caution on the sleeper stretch, which a lot of throwers are taught to fix internal rotation. Pressing the arm passively into internal rotation can increase range without building any control in it, and done aggressively it can irritate a shoulder that’s already sore. It’s worth having someone check what’s limiting internal rotation before pushing hard on it.

Youth throwers

Young throwers are a different case. Their bones are still developing, and the research on pitch counts and rest exists because overuse in growing arms causes injuries that look different from adult ones. Range and control work helps, and it still can’t offset throwing too much. If a young athlete has elbow or shoulder pain that doesn’t settle with rest, they should see a sports medicine physician.

Where to start

The most useful first step for a thrower is knowing their numbers, meaning rotation on both sides and how much of that range they can control. That’s part of what we measure in our movement assessments for athletes. From there the training can address what that particular shoulder needs.

References

Written by

Brian Murray, FRA, FRSC

Founder of Motive Training

Motive Training is a coaching studio in South Austin built around assessment, joint health, and strength you can use. Train with us in the studio, come to a KINSTRETCH class, or work through the progressions in KINSTRETCH Online.

Mobility Training for Throwing Athletes: The Shoulder, the Scapula, and the Rest of the Throw