Graduation Term

2022

Degree Name

Master of Science (MS)

Department

School of Kinesiology and Recreation

Committee Chair

Nicole L Hoffman

Abstract

Context: Posterior shoulder tightness is common among collegiate overhead athletes due to repetitive overhead patterns, often resulting in altered range of motion patterns. This may be associated with additional non-painful hypersensitive areas of taut muscle called latent myofascial trigger points (LTrPs), which have been linked to muscle imbalances, muscular weaknesses, impaired motor recruitment, and internal rotation (IR) range of motion (ROM) deficits. Evidence supports improvements in glenohumeral ROM and isometric strength through instrument assisted manual therapy techniques on MTrPs in baseball players. Ischemic compression (IC) is a form of therapeutic myofascial release that can be performed by any clinician trained in manual therapy. Although improvement in ROM and isometric strength have been indicated within other regions of the body, it is unknown if IC treatment of LTrPs will improve glenohumeral ROM and isometric strength in overhead athletes.Objective: The purpose of this study was to determine the relationship between short- and long-term repeated IR ROM and ER isometric strength measurements before and after IC treatment compared to sham compression. Study Design and Setting: Single-blinded randomized controlled trial in a controlled athletic training laboratory. Patients or Other Participants: Forty healthy Division I collegiate overhead athletes (age: 20.31.6 years) from baseball, cheer, circus, softball, swimming, track and field, and volleyball were included in this study. Participants were excluded if they did not have a total arc ROM deficit of ≥5° in the dominant shoulder compared to the ideal 180° for overhead athletes or deficits of ≥20° of IR compared to the contralateral shoulder, had at least two LTrPs in the dominant shoulder infraspinatus muscle, or scored <70% on the Kerlan-Jobe Orthopedic Clinic scores (KJOC) or Penn Shoulder Scores (PSS) questionnaires. Intervention: Participants were randomly allocated to one of two intervention groups; IC or sham IC. Participants in the IC group completed passive IR glenohumeral ROM and ER isometric strength measurements before and immediately after IC treatment session #1, within 24-48 hours of IC treatment session #1, and final measurements taken within 24-48 hours after IC treatment session #2. The sham IC group completed the same procedures as the IC group, except investigators did not apply manual pressure to MTrPs. Main Outcome Measures: Passive glenohumeral IR ROM, ER isometric strength, and pain-pressure threshold (measured by a digital pressure algometer). The KJOC and PSS were used to determine each participant’s perceived level of dominant shoulder function before and after interventions. Results: Dominant shoulder passive glenohumeral IR ROM did not increase following the IC or sham interventions. Individuals who received IC did not demonstrate significant ER strength gains compared to baseline, but individuals who received sham compression demonstrated a significant decrease in overall ER isometric strength during the final measurement time-point compared with baseline (-1.63 ±1.93) versus the IC group (-0.20±1.66; F(1, 28)=6.32, p=0.016, η2p=0.17). Pain-pressure threshold showed a greater decrease in the 1st LTrP at the first post-intervention time-point compared to baseline in the IC group (-1.49±1.56) versus sham (-0.53±1.23, F(1, 28)=4.68, p=0.037). No differences in pain-pressure threshold in the first LTrP were found at the other time-points. Conclusion: Our findings suggest that ischemic compression may not be an effective treatment method for improving glenohumeral IR ROM and/or ER isometric strength. Additional research is required to completely understand, implement, and/or rule out the use of ischemic compression on LTrPs as a treatment for glenohumeral IR ROM and ER isometric strength in healthy collegiate overhead athletes.

KEYWORDS: external rotation, infraspinatus, internal rotation, ischemic compression, isometric strength, latent trigger point, myofascial trigger point, pain-pressure threshold, range of motion

Access Type

Thesis-Open Access

DOI

https://doi.org/10.30707/ETD2022.20220705065053721934.999971

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