The Influence of Rotator Cuff Stiffness on Shoulder Range of Motion

An excellent article investigating the cause of shoulder range of motion deficits in asymptomic baseball players was recently published in the American Journal of Sports Medicine (AJSM).(1)  The group at Proaxis Physical Therapy out of Greenville, South Carolina wanted to better understand how much influence the capsule, rotator cuff, and bony alignment of the shoulder had on range of motion deficits.
They designed a study that involved one group of athletes stretching (using the sleeper and cross body stretch) for four minutes, while the other group performed the same amount of stretching, but also received four minutes of instrument-assisted soft tissue mobilization (ISTM) to the infraspinatus.
The results of the study showed that those who underwent both stretching and ISTM of their dominant shoulder showed 12.1 degrees improvement with internal rotation and 13.5 degrees improvement of horizontal adduction which was 5 and 7 degrees more than the stretching groups respectively.  These findings also support a study Laudner and colleagues published in 2014 showing significant improvements of internal rotation and horizontal adduction following only 40 seconds of ISTM to the posterior axillary border.(2)
In the conclusion of the recent AJSM publication, the authors state that by decreasing stiffness of the rotator cuff acute range of motion gains were noted.  “The study results show that changes in rotator cuff stiffness, not glenohumeral joint mobility or humeral torsion, are most likely associated with the range of motion deficits observed in adolescent baseball players.”
So, why are these findings important and how can they be applied to caring for overhead athletes?  These studies show that restricted soft tissue surrounding the shoulder girdle, specially the rotator cuff, can contribute to internal rotation deficit in the dominant arm of throwing athletes.  Like I mentioned in my last post, this can lead to increased risk of shoulder injury.   So, reducing rotator cuff stiffness with manual therapy directed at the soft tissue can improve range of motion, which may be beneficial in decreasing injury risk.
The literature is showing the added benefit of soft tissue work, but in the athletic training room it’s difficult and challenging to provide this to each athlete before they practice and compete.  As a physical therapist and athletic trainer myself, I’ve experienced fatigued hands and struggling to keep up with the demands.  The T-Dot Mobility System was developed to assist in providing the athlete the needed soft tissue work and increase their independence in managing the health of their arm.  This wasn’t intended to replace trained hands, but can supplement programming to assist in providing exceptional care.  In summary, getting to the soft tissue of the shoulder is important it shouldn’t go overlooked when treating overhead athletes.
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  1. Bailey LB, Shanley E, Hawkins R, et al. Mechanism of Shoulder Range of Motion Deficits in Asymptomatic Baseball Players. Am J Sports Med. Published online September 24, 2015.
  2. Laudner K, Compton BD, McLoda TA, Walter CM. Acute effects of instrument assisted soft tissue mobilization for improving posterior shoulder range of motion in collegiate baseball players. Int J Sports Phys Ther. 2014; 9: 1-7. 

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.

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