Author Names
Moore, S. D., Laudner, K. G., Mcloda, T. A., & Shaffer, M. A
Reviewer Name
Marie-Adelaide Robinson, SPT
Reviewer Affiliation(s)
Duke University School of Medicine, Doctor of Physical Therapy Division
Paper Abstract
Study Design: Randomized controlled trial. Objective: 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.
NIH Risk of Bias Tool
Quality Assessment of Controlled Intervention Studies
- Was the study described as randomized, a randomized trial, a randomized clinical trial, or an RCT
- Yes
- Was the method of randomization adequate (i.e., use of randomly generated assignment)?
- Yes
- Was the treatment allocation concealed (so that assignments could not be predicted)?
- Yes
- Were study participants and providers blinded to treatment group assignment?
- No
- Were the people assessing the outcomes blinded to the participants’ group assignments?
- Cannot Determine, Not Reported, or Not Applicable
- Were the groups similar at baseline on important characteristics that could affect outcomes (e.g., demographics, risk factors, co-morbid conditions)?
- Yes
- Was the overall drop-out rate from the study at endpoint 20% or lower of the number allocated to treatment?
- Yes
- Was the differential drop-out rate (between treatment groups) at endpoint 15 percentage points or lower?
- Yes
- Was there high adherence to the intervention protocols for each treatment group?
- Yes
- Were other interventions avoided or similar in the groups (e.g., similar background treatments)?
- Cannot Determine, Not Reported, or Not Applicable
- Were outcomes assessed using valid and reliable measures, implemented consistently across all study participants?
- Yes
- Did the authors report that the sample size was sufficiently large to be able to detect a difference in the main outcome between groups with at least 80% power?
- Cannot Determine, Not Reported, or Not Applicable
- Were outcomes reported or subgroups analyzed prespecified (i.e., identified before analyses were conducted)?
- Yes
- Were all randomized participants analyzed in the group to which they were originally assigned, i.e., did they use an intention-to-treat analysis?
- Yes
Key Finding #1
Following one application of MET of the horizontal abductors, collegiate asymptomatic baseball players had immediate improvement in glenohumeral internal rotation and horizontal adduction range of motion in the dominant arm.
Key Finding #2
Acute application of MET on glenohumeral joint posterior shoulder ROM can help prevent shoulder injuries related to GIRD and posterior shoulder tightness.
Please provide your summary of the paper
This study showed that a single application of a muscle energy technique of the horizontal abductors improved glenohumeral (GH) internal rotation and horizontal adduction range of motion in the dominant arm of asymptomatic collegiate baseball players. Each player was randomly assigned a group and the researcher measuring range of motion was blinded to the groupings, however the provider performing the MET was not blinded. Limitations of the study included the frequency of sessions and lack of post intervention follow up to see if continued MET would provide more permanent benefits. As this study based its findings on a singular session of MET, it is unclear if continued use of MET will provide long-term benefits or just an acute outcome. The study referenced that stretching of the GH joint internal rotators in overhead athletes proved successful in regaining and maintaining increased ROM, however the specific techniques of stretching the posterior capsule remain inconsistent. I believe this study did an adequate job trying to isolate the posterior capsule in the GH when conducting the MET to provide more specific data to supplement existing research.
Please provide your clinical interpretation of this paper. Include how this study may impact clinical practice and how the results can be implemented.
Overall, the findings of the study provide physical therapists or athletic trainers another technique to help overhead athletes increase internal rotation and horizontal adduction range of motion. Like the study mentioned, there are techniques such as the sleeper stretch that can aid in increasing range of motion. However, I believe this specific technique of MET isolates the posterior shoulder and can target the internal rotators and horizontal adductor muscles with greater efficiency to improve range of motion.
