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Improve Shoulder Mobility With IASTM

Tight Shoulders? Try IASTM.

Pitchers and catchers officially start workouts this week, so we can finally start getting excited for baseball season! We thought it would be a good time to highlight a recent study that looked at the effect of IASTM treatment on the shoulders of baseball players.

This paper published in the International Journal of Sports Physical Therapy was titled ‘Acute effects of instrument assisted soft tissue mobilization for improving posterior shoulder range of motion in collegiate baseball players' (3).


GIRD diagramRepeated high intensity throwing can cause some profound effects on the range of motion and mechanics of the shoulder. In elite baseball players it is common to see an increase in glenohumeral (shoulder joint) external rotation, and a corresponding decrease in internal rotation and horizontal adduction (1). 

These changes in shoulder range of motion are due to changes in the tension of soft tissues, and possible bone adaptation because of the repeated stresses being put through the shoulder (3). With repeated throwing, the tensile force that is exerted on the shoulder that possesses these limitations in its range of motion can be detrimental and may lead to injury (2).

If a lack of glenohumeral internal rotation and horizontal adduction could pre-dispose an athlete to injury, it follows that improving this range of motion, may be helpful for injury prevention.

The researchers in this study employed an Instrument Assisted Soft Tissue Mobilization (IASTM) technique to the musculature of the shoulder and investigated the effects on range of motion (3).

What Did They Find?

baseball pitching shoulderResearchers worked through the musculature of the posterior shoulder (infraspinatus, teres major/minor, posterior deltoid, latissimus dorsi) using an IASTM tool. After IASTM treatment, researches found a clinically significant improvement in glenohumeral internal rotation by 4.8°and horizontal adduction by 11.1° (3).


If you are working with baseball players who exhibit limitation in shoulder range of motion, this study demonstrates that IASTM could be a helpful treatment modality for improving both shoulder internal rotation and horizontal adduction in the arms of baseball players.


Bigliani LU, Codd TP, Connor PM, Levine WN, Littlefield MA, Hershon SJ. Shoulder motion and laxity in the professional baseball player. Am J Sports Med. 1997 Sep-Oct;25(5):609-13.

Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology Part I: pathoanatomy and biomechanics. Arthroscopy. 2003 Apr;19(4):404-20.

Laudner K, Compton BD, McLoda TA, Walters CM. Acute Effects of Instrument Assisted Soft Tissue Mobilization For Improving Shoulder Range of Motion in Collegiate Baseball Players. International Journal of Sports Physical Therapy. 2014;9(1):1-7.