Study design: Randomized controlled trial.
Objectives: To compare a muscle energy technique (MET) for the glenohumeral joint (GHJ) horizontal abductors and an MET for the GHJ external rotators to improve GHJ range of motion (ROM) in baseball players.
Background: Overhead athletes often exhibit loss of GHJ ROM in internal rotation, which has been associated with shoulder pathology. Current stretching protocols aimed at improving flexibility of the posterior shoulder have resulted in inconsistent outcomes. Although utilization of MET has been hypothesized to lengthen tissue, there are limited empirical data describing the effectiveness of such stretches for treating posterior shoulder tightness.
Methods: Sixty-one Division I baseball players were randomly assigned to 1 of 3 groups: MET for the GHJ horizontal abductors (n = 19), MET for the GHJ external rotators (n = 22), and control (n = 20). We measured preintervention and postintervention GHJ horizontal adduction and internal rotation ROM, and conducted analyses of covariance, followed by Tukey honestly significant difference post hoc analysis for significant group-by-time interactions (P<.05).
Results: The group treated with the MET for the horizontal abductors had a significantly greater increase in GHJ horizontal adduction ROM postintervention (mean ± SD, 6.8° ± 10.5°) compared to the control group (-1.1° ± 6.8°) (P = .011) and a greater increase in internal rotation ROM postintervention (4.2° ± 5.3°) compared to the group treated with the MET for the external rotators (0.2° ± 6.3°) (P = .020) and the control group (-0.2° ± 4.0°) (P = .029). No significant differences among groups were found for any other variables (P>.05).
Conclusion: A single application of an MET for the GHJ horizontal abductors provides immediate improvements in both GHJ horizontal adduction and internal rotation ROM in asymptomatic collegiate baseball players. Application of MET for the horizontal abductors may be useful to gain ROM in overhead athletes.
Level of evidence: Therapy, level 2b-.