Vibration-Enhanced Suspension Training for Glenohumeral Stability and Strength after Shoulder Subluxation: A Case Series

Background While suspension and vibration training offer several benefits across various body regions, evidence for injury rehab remains limited. Hypothesis/Purpose The purpose of this case series was to examine the effect of seven weeks of strength training using a novel vibration device (superimposed vibration with 40 Hz frequency) with an attached suspension strap on two subjects recovering from a shoulder subluxation. Methods Two physically active men who had sustained prior non-dominant subluxation underwent seven weeks of strength training using a suspension device operating at 40 Hz. An intervention comprising six exercises was performed twice weekly for seven weeks, divided into two blocks of three exercises: Block 1) suspended chest fly, inverted row, shoulder taps; Block 2) elbow flexion, standing overhead triceps extension, and the side plank. They performed three sets of eight repetitions in each block, resting 30 seconds between exercises and three minutes between blocks. Eight touches were performed per arm during the shoulder taps exercise, and the side plank was held for 25 seconds on each side. In addition to assessments of range of motion (ROM) and strength, the Y-Balance Test-Upper Quarter (YBT-UQ) and Closed Kinetic Chain Upper Extremity Stability Test (CKUEST) tests were performed to glenohumeral stability, and strength. Results: The greatest ROM improvements (~50%) were found in the internal rotation (IR) compared to a 5% in flexion and 20% in external rotation (ER). Glenohumeral stability increased in all the positions of the YBT-UQ for the injured arm (5% to 33% depending on the position), and the CKUEST (10-20%). Additionally, significant gains were seen in the injured arm during isometric push and pull tests (around 10%), but no differences in the dynamic strength in the bench press exercise force velocity profile. Conclusions Using vibration-enhanced suspension training improved the joint stability and strength of the two subjects without adverse effects. Additional research is needed to confirm these findings.