BACKGROUND & OBJECTIVE
Typically, an injury causes acute pain, but pain subsides over time as the injury heals. In some patients, however, pain continues long after the injury has healed. In these patients, their central nervous system remains hypervigilant, perceiving normal movement as threatening and painful. This phenomenon is called central sensitization. It may be caused by psychosocial factors including fear avoidance and pain catastrophization. One strategy for treating central sensitization is graded motor imagery. Graded motor imagery typically consists of several sequential steps including pain neuroscience education, motor imagery, and mirror therapy. The purpose of this study was to determine if mirror therapy alone could improve active range of motion (AROM) and mitigate psychosocial factors in patients with shoulder pain and limited range of motion (ROM).
Sixty-nine patients with shoulder pain (35 females, 34 males; average age = 58 ± 17) participated in the study. All participants had limited shoulder flexion AROM, defined as a 10Â° or greater difference between sides. The most common diagnoses were impingement, a surgically repaired rotator cuff, and total shoulder replacement.
For the mirror therapy intervention, patients sat in a chair next to a full-length mirror that faced their uninvolved arm. With the involved arm behind the mirror, patients performed 10 slow repetitions of full AROM of the uninvolved arm. The mirror gave the illusion that they were moving their involved arm pain-free. The intervention took an average of three minutes. Four outcome measures were assessed pre- and post-intervention and analyzed using paired t-tests:
- Shoulder flexion AROM of the affected arm, using a goniometer
- Self-reported pain, using a numeral pain rating scale
- Pain catastrophization, using the Pain Catastrophization Scale (range: 0-52, with higher scores indicative of elevated catastrophization)
- Fear of movement, using the Tampa Scale of Kinesiophobia (range: 17-68, with higher scores indicative of increased fear of movement)
Shoulder flexion AROM of the affected arm increased significantly following the mirror therapy intervention. The observed mean increase (14.5°) represented a large effect and exceeded the minimum detectable change (8°), indicating a true change beyond measurement error. There were also