The T-Dot Mobility System: A Different Approach to Improving Shoulder Internal Rotation

​Loss of shoulder internal rotation in overhead sports is something that just happens.  It can be seen in several sports with baseball usually being at the forefront, but it can also pop up in weight rooms and other arenas where stress is placed on the shoulder overhead.   Many have suggested this can be caused by bony alignment, posture changes, posterior capsule tightness, and musculotendinous tightness.(1)

Over the years, several ways have been proposed to improve internal rotation or prevent the loss of internal rotation from occurring, as research has proposed that substantial loss of glenohumeral internal rotation has been tied to increased risk of shoulder injury.(2,3)

The sleeper stretch and the cross body stretch have been, and continue to be used as treatment options to improve internal rotation.   Modifications of both of these stretches have been made to help increase their effectiveness, but how much of a difference do they make?  If we start with the sleeper stretch, one study showed an acute improvement of 3.1 degrees in college baseball players.(4)  Another showed a 12.4 degree improvement in shoulder internal rotation after performing the stretch daily for four weeks, but didn’t use symptomatic subjects or overhead athletes.(5) 

As of late, several clinicians have preferred the cross body stretch over the sleeper stretch.  It tends not to put an athlete into the “impingement” position, which decreases the subacromial space and can cause pain in the shoulder.  Also, with the assistance of a clinician or positioning themselves against the wall, there is improved stabilization of the scapula to direct the stretch at the posterior shoulder.  Acute improvement of 11 degrees was shown following the cross body stretch in 16 year-old volleyball players with a clinician stabilizing the scapula.(6)  When comparing it to the sleeper stretch and performing daily over four weeks subjects did show a 20 degree improvement.(5)

Using the cross body stretch as the standard for improving shoulder internal rotation, I wanted to compare it to one of our pec minor protocols on the T-Dot Mobility System.  I used a single subject’s left shoulder.  He is a 39 year-old male with a history of a rotator cuff tear.  He is a Crossfit coach and is performing overhead activities on a regular basis.  For the first round of testing, I measured his internal rotation prior to performing the cross body stretch.  Then, he used the T-Dot to stabilize the scapula when performing the stretch and it was performed 3 times holding for 30 seconds with a 10 second rest in-between sets.

​The acute impact of the cross body stretch wasn’t as influential as I’d expected.  A 2 degree change was noted as the difference when comparing pre and post-intervention, which was significantly less than Salamh, et al. noted in their study.  They were looking at 16 year-old females, which tend to be more hypermobile than most, asymptomatic, and the stretch was also clinician aided – so those were primary differences observed.
Twelve days later, pre-intervention measurements were taken and then he completed our pec minor protocol which took 1 minute 45 seconds to complete.  He performed 15 reps of shoulder flexion while leaning into the T-Dot with pressure on the pec minor.  That was followed up with 15 reps of horizontal abduction and 15 reps of shoulder external rotation at 90 degrees of abduction.  A short example of this protocol is shown in the first half of the video below.

The acute impact of the T-Dot Protocol was much more drastic than what I saw with the cross body stretch.  The subject showed 13 degrees improvement in internal rotation while spending approximately the same amount of time working on improving motion as he did with the cross body stretch. 

So the next question most people ask after seeing these changes is “What’s causing this?” or “Why does my shoulder feel so much looser?”  The T-Dot is different with its approach because we are focusing on reducing muscular tension on the shoulder through pressure and movement at the muscles that attach to the scapula.  The cross body and sleeper stretch are more directed at the posterior capsule, which can be restricted in overhead athletes, but our hypothesis is we are modifying musculotendinous tightness and scapulothoracic position that can also be involved in internal rotation loss.

By looking at the pectoralis minor anatomically, it originates at ribs 3-5 and inserts at the coracoid process on the scapula.  I think what we are seeing is that by decreasing tension on the coracoid process/scapula, the position of the scapula is changed, which alters the position of the glenoid fossa, and therefore changes how the head of the humerus sits in the glenoid.  Ultimately this would impact internal rotation motion at the glenohumeral joint. 

The challenge at this point in time is there is minimal to no formal research that has been conducted looking at addressing the anterior shoulder and how this impacts shoulder rotational range of motion.  I am thankful for the team we have on board who has been willing to investigate this concept more and work toward publishing formal research on the T-Dot Mobility System.

I look forward to sharing more in the months to come discussing concepts that make the T-Dot Mobility System work.  We didn’t reinvent the wheel, but have taken established principles and built them into a system that allows the user to independently improve their movement and function.

To learn more about the T-Dot Mobility System, check out 

1.    Wilk KE, Hooks TR, Macrina LC. The Modified Sleeper Stretch and Modified Cross-body Stretch to Increase Shoulder Internal Rotation Range of Motion in the Overhead Throwing Athlete. J Orthop Sports Phys Ther. 2013; 43: 891-894.
2.    Wilk KE, Macrina LC, Fleisig GS, et al. Cor¬relation of glenohumeral internal rotation deficit and total rotational motion to shoulder injuries in professional baseball pitchers. Am J Sports Med. 2011; 39: 329-335.
3.    Myers JB, Laudner KG, Pasquale MR, Bradley JP, Lephart SM. Glenohumeral range of motion defi¬cits and posterior shoulder tightness in throwers with pathologic internal impingement. Am J Sports Med. 2006; 34: 385-391.
4.    Laudner KG, Sipes RC, Wilson JT. The acute effects of sleep stretches on shoulder range of motion. J Athl Train. 2008; 43: 359-363.
5.    McClure P, Balaicuis J, Heiland D, Broersma ME, Thorndike CK, Wood A. A randomized controlled comparison of stretching procedures for posterior shoulder tightness. J Orthop Sports Phys Ther. 2007; 37: 108-114.
6.    Salamh PA, Kolber MJ, Hanney WJ. Effect of Scapular Stabilization During Horizontal Adduction Stretching on Passive Internal Rotation and Posterior Shoulder Tightness in Young Women Volleyball Athletes: A Randomized Controlled Trial. Arch Phys Med Rehabil. 2015; 96: 349-356

Brett Burton PT, DPT, SCS, ATC, CSCS

Brett is a performance physical therapist at EXOS in Phoenix, AZ. He has a passion for human performance, helping people get out of pain, and improving movement efficiency. He completed his athletic training and physical therapy education at the University of Nebraska. He joined Movement Guides in 2015 while he was completing a physical therapy residency program in Idaho and shortly after joining the team, the T-Dot Mobility System was established.

Leave a Comment