Laser testing for upper extremity proprioceptive deficits following rotator cuff injury: two case reports

Background: Rotator cuff (RTC) dysfunction incidence ranges from 7% to 25% in the general population with a high recurrence rate. RTC musculature plays a significant role in dynamic stability of the glenohumeral joint with damage to these structures associated with proprioceptive impairments. Impaired proprioception has been linked to increased injury risk in other body regions; however, similar relationships with the upper extremity have not been extensively evaluated. The purpose of this case report is to present a preliminary, yet clinically feasible approach for using a laser for proprioceptive assessment and treatment in patients with RTC dysfunction. Case description: Patient 1 was a 21-year-old female with right shoulder pain from injury at work as a waitress where she lifted a heavy tray of plates. Patient 2 was a 48-year-old male with gradual and insidious onset of right shoulder pain during recreational baseball. Examination findings indicated contractile tissue involvement in both patients. Reaching and throwing tasks requiring accurate proprioceptive function were essential for return of each patient to their functional tasks. Laser proprioception testing was performed every 2 weeks with proprioceptive training provided as a supplement to other interventions. Outcomes: Over 4 weeks, improvements in objective laser proprioceptive test results were observed for both patients (Patient 1 = 6.0 cm; Patient 2 = 5.5 cm) in conjunction with active range-of-motion and self-report measures for pain intensity and function. Discussion: This case report describes a clinically feasible approach to testing and treating upper extremity proprioceptive deficits after RTC injury. Future research is required to establish reliability and validity of these methods.