Does Integration of Graded Motor Imagery Training Augment the Efficacy of a Multimodal Physiotherapy Program for Patients With Frozen Shoulder? A Randomized Controlled Trial
Authors: Yasaci Zeynal , Celik Derya 
Published: October 2024

Background
Despite the availability of numerous treatment modalities for frozen shoulder, spanning from nonsurgical approaches to surgical interventions, a consensus regarding the most effective treatment remains elusive. Current studies emphasize that pain in frozen shoulder affects central nervous system activity and leads to changes in cortical structures, which are responsible for processing sensory information (like pain) and controlling motor functions (like movement). These cortical changes highlight the importance of including the central nervous system in the management of frozen shoulder. It is therefore recommended that treatment should provide more effective management by focusing not only on the shoulder region but also on the cortical areas thought to be affected.

Questions/purposes
Among patients treated nonsurgically for frozen shoulder, is graded motor imagery added to a multimodal physical therapy program more effective than multimodal physical therapy alone in terms of (1) Shoulder Pain and Disability Index (SPADI) scores, (2) pain with activities and QuickDASH (Q-DASH) scores, and (3) ROM after 8 weeks of treatment?

Methods
In this randomized clinical trial, we considered the following as eligible for inclusion: (1) ROM < 50% compared with the unaffected shoulder, (2) clinically and radiologically confirmed primary frozen shoulder, and (3) 30% loss of joint ROM in at least two planes compared with the unaffected shoulder. Diagnosis of patients was based on patient history, symptoms, clinical examination, and exclusion of other conditions. A total of 38 patients with frozen shoulder were randomly assigned to either the graded motor imagery group (n = 19) or the multimodal physiotherapy group (n = 19). The groups did not differ in age, height, weight, gender, and dominant and affected side. In both groups, there were no losses to follow-up during the study period, and there was no crossover between groups. The multimodal physiotherapy program encompassed a variety of treatments, including stretching exercises, ROM exercises, joint-oriented mobilization techniques, scapular mobilization, strengthening exercises, and the application of cold agents. The graded motor imagery program, as an addition to the multimodal physiotherapy program, included the following steps: (1) left-right discrimination (identifying left and right body parts), (2) motor imagery (mentally visualizing movements), and (3) mirror therapy training (using mirrors to trick the brain into thinking the affected part is moving). Both groups of patients participated in a program of 12 sessions, each lasting approximately 45 minutes, twice a week for 6 weeks. Participants were assessed at baseline, after 6 weeks, and at 8 weeks. The primary outcome was the SPADI score, which ranges from 0 to 100, with higher values denoting greater disability. The minimum clinically important difference (MCID) for SPADI scores is reported to be 13.2 points. Secondary outcomes were shoulder ROM, Numeric Pain Rating Scale activity score (scored from 0 points, indicating “no pain,” to 10 points, indicating “worst pain imaginable”), and Q-DASH score (ranging from 0 to 100 points, with a higher score indicating higher functional disability). Repeated-measures analysis of variance was used to compare means between one or more variables based on repeated observations.

Results
After 8 weeks of treatment, patients treated with graded motor imagery plus multimodal physical therapy experienced greater mean ± SD improvement from baseline in terms of SPADI scores than did the multimodal physical therapy group (65 ± 9 versus 55 ± 12, mean difference 10 points [95% confidence interval 4 to 17 points]; p = 0.01). Graded motor imagery when added to standard therapy did not produce a clinically important difference in pain scores with activity compared with physical therapy alone (7.0 ± 1.3 versus 5.9 ± 1.4, mean difference 1 point [95% CI 0.2 to 2.0 points], which was below our prespecified MCID; p = 0.04). However, improvements in Q-DASH score at 8 weeks were superior in the graded motor imagery group by a clinically important margin (58 ± 6 versus 50 ± 10, mean difference 9 points [95% CI 3 to 14 points], which was below our prespecified MCID; p = 0.01). ROM was generally better in the group that received the program augmented by graded motor imagery, but the differences were generally small.

Conclusion
Adding graded motor imagery to a multimodal physiotherapy program was clinically superior to multimodal physiotherapy alone in improving function in patients with frozen shoulder. However, no clinically superior scores were achieved in ROM or activity-related pain. Additionally, the follow-up period was short, considering the tendency of frozen shoulder to recur. Although adding graded motor imagery provides superiority in many scores and does not require high-budget equipment, the disadvantages such as the difference in some scores being sub-MCID and the need for expertise and experience should not be ignored. Consequently, while graded motor imagery shows promise, further research with longer follow-up periods is recommended to fully understand its benefits and limitations in the treatment of frozen shoulder.

Level of Evidence
Level I, therapeutic study.