The Immediate Effects on Shoulder Internal Rotation Motion and External Rotation Strength Following a Muscle Energy Technique in a Young Overhead Thrower: A Case Report.

Introduction: Glenohumeral internal rotation deficit (GIRD), total rotational motion (TRM) deficit, and weakness of the rotator cuff have been determined to be potential risk factors for the development of shoulder and elbow injuries in the overhead thrower. The causes for these deficiencies are multifactorial and the ability to identify and correct those deficits could decrease the potential for injury. Therefore, the purpose of this case report was to investigate the immediate effects of a muscle energy technique (MET) on shoulder internal rotation ROM and external rotation strength in the throwing shoulder of an overhead thrower.

Case description: The subject of this case report was a 20-year-old collegiate baseball pitcher without any reported previous injury that presented with a loss of passive shoulder internal rotation at 90 degrees of abduction, a deficit in TRM, and weakness of the external rotators as determined by handheld dynamometry. The athlete was identified during a pre-sport screening for overhead throwers. Following the assessment, a MET was performed for shoulder internal rotation in a side-lying position.

Outcome: The athlete demonstrated an immediate 38-degree improvement in shoulder internal rotation motion, reduction in TRM deficit from 42 degrees to 4 degrees, and 7.8% increase in shoulder external rotation strength.

Discussion: It is not uncommon for symptomatic and asymptomatic overhead throwers to present with GIRD, TRM deficit, and rotator cuff weakness. The ability to improve these deficits following the application of a MET could imply that the deficits are linked. Previous studies have identified different methods that improve internal rotation ROM but have not documented possible related outcomes in external rotation strength. Future research should examine the potential mechanism for such a response to the MET, and if these changes have a lasting effect, as only short-term effects were examined.

Level of evidence: 4.