Effects of Sling-Suspension-Based Active Shoulder Joint Exercise on Shoulder Joint Subluxation, Pain, Muscle Strength, and Upper Limb Function in Patients with Subacute Stroke

<i>Background and Objectives</i>: We investigated the effects of sling-suspension-based active shoulder joint exercise training on shoulder joint subluxation, pain, muscle strength, and upper extremity function in patients with subacute stroke. <i>Materials and Methods</i>: Twenty-eight patients with subacute stroke were randomly assigned to either the sling-suspension-based active shoulder joint exercise (SASE) group (<i>n</i> = 14) or the motorized upper extremity exercise (MUEE) group (<i>n</i> = 14). The SASE group actively performed shoulder joint flexion, extension, abduction, adduction, external and internal rotation, and horizontal abduction and adduction using a sling suspension system, whereas the MUEE group underwent an exercise program using a motorized upper extremity exercise machine. All participants underwent a 4-week intervention with 30 min of exercise once a day for 5 days a week. Additionally, both groups received general physical therapy and functional electrical stimulation for 30 min twice a day for 5 days a week. Shoulder joint subluxation was measured by radiographic examination before and after training, and pain was evaluated in the splenius, upper trapezius, and infraspinatus muscles using pressure parameters. In addition, a manual muscle tester was used to assess the muscle strength of the shoulder joint flexors, extensors, abductors, adductors, and external and internal rotators, and the Fugl-Mayer Assessment (FMA) and Manual Functional Test (MFT) were used to evaluate upper extremity function. <i>Results</i>: A significant group-time interaction was observed for pain, with F-values of <i>F</i>(1, 26) = 7.470, <i>p</i> < 0.011 for the splenius and <i>F</i>(1, 26) = 9.623, <i>p</i> < 0.005 for the upper trapezius. A significant time-group interaction was observed for the muscle strength of the shoulder, with F-values of <i>F</i>(1, 26) = 13.211, <i>p</i> < 0.001; <i>F</i>(1, 26) = 4.974, <i>p</i> = 0.035 and <i>F</i>(1, 26) = 9.674, <i>p</i> = 0.004 for flexors, abductors, and external rotators, respectively. A significant time-group interaction was observed in the FMA, with F-values of <i>F</i>(1, 26) = 13.243, <i>p</i> < 0.001. When comparing the interaction effects between time and group for MFT scores, a significant difference was observed, with F-values of <i>F</i>(1, 26) = 32.386, <i>p</i> < 0.001. <i>Conclusions</i>: This study confirmed that sling-suspension-based active shoulder joint exercises are effective in improving shoulder joint subluxation, pain, muscle strength, and upper extremity function in patients with subacute stroke.