Comparison of Instrument-Assisted Soft Tissue Mobilization and Passive Stretching to Improve Glenohumeral Range of Motion and Function
Abstract
Context: The loss of shoulder internal rotation range of motion is common maladaptation that predisposes overhead sport athletes to injury. Instrument-assisted soft tissue mobilization (IASTM) has recently been suggested as an alternative to stretching exercises to reestablish normal range of motion. Objective: To determine the extent to which a 4-week program of traditional stretching plus IASTM improves glenohumeral range of motion compared to stretching alone. Our secondary purpose was to measure the effects of these interventions using two patient-rated outcome measures of shoulder function. Design: Prospective cohort study. Setting: Combined laboratory and field study. Participants: 20 intercollegiate baseball players; 10 in the Stretching + IASTM Group (age, 20.9 ± 0.9 yrs; height, 180.8 ± 8.1 cm; mass 85.7 ± 7.2 kg), and 10 in the Stretching group (age, 19.9 ± 1.4 yrs; height, 183.4 ± 7.4 cm; mass, 87.1 ± 8.5 kg). Interventions: Participants in the Stretching group received a clinician-administered shoulder stretching program 5 days/week for 4 weeks. Participants assigned to the Stretching + IASTM group received the same stretching program, plus IASTM treatments twice per week for 4 weeks. All participants completed the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow (KJOC) score and the Functional Arm Scale for Throwers (FAST) at the beginning and end of the study. Main Outcome Measures: Shoulder internal rotation, external rotation, and horizontal adduction passive range of motion (PROM); glenohumeral total range of motion (TROM); and the KJOC and the FAST. Statistical Analyses: Five Group (2) x Time (2) between-within ANOVAs were performed (α = 0.05). We also calculated Pearson correlations between the KJOC and FAST questionnaire scores. Results: Internal rotation PROM significantly improved from Week 0 to Week 4 in both treatment groups (p = 0.005). Stretching group mean internal rotation PROM increased 6.3%, from 52.8º + 8.7º to 56.1º + 8.4º, while Stretching + IASTM group average internal rotation PROM improved 7.8%, from 52.6º + 7.2º to 56.7º + 4.5º over the course of this study. Total range of motion (TROM) improved 3.1% in the Stretching group, from 145.2º + 17.0º to 149.7º + 18.4º, and 4.2% in the Stretching + IASTM group, from 143.0º + 8.4º to 149.0º + 10.6º between Week 0 and Week 4, respectively (p = 0.005). The KJOC and the FAST scores were inversely related at both the outset (r = -0.874, p = 0.001) and conclusion of our 4-week intervention (r = -0.765, p = 0.001). Conclusions: While both treatment protocols were effective in increasing glenohumeral internal rotation PROM and TROM, the IASTM protocol we employed did not have a significant effect on any of our disease-oriented outcome measures after 4 weeks. Future research studies should compare the effects of multiple IASTM treatment frequencies and durations to more fully evaluate the capacity of IASTM to create long-term improvements in glenohumeral joint range of motion and function.
