The study included a small study population from a single center, which limits the interpretation of the findings. Therefore, the results of the present study should be verified by additional studies with larger sample sizes. Persistent long-term effects were not evaluated because there were was no follow-up after the four-week therapeutic intervention was completed. Long-term follow-up studies should be conducted to confirm the effect of active shoulder joint exercises with the sling suspension system. Also, further studies should be performed to compare the baseline data of the control group without upper limb movement because bilateral upper extremity exercises in the control group led to active assisted movement of the shoulder joint in the paralyzed arm.