Upper limb active joint repositioning during a multijoint task in participants with and without rotator cuff tendinopathy and effect of a rehabilitation program.

STUDY DESIGN: Cross-sectional and longitudinal (exploratory) studies. INTRODUCTION: Rotator cuff (RC) tendinopathy is the most prevalent shoulder diagnosis, and proprioception deficits are often observed in individuals with RC tendinopathy. PURPOSE OF THE STUDY: This study aimed to evaluate upper limb proprioception during a multijoint task in participants with and without RC tendinopathy and to determine if symptoms, functional limitations, and proprioception are improved after a rehabilitation program. METHODS: Twenty participants with and 20 without RC tendinopathy were recruited for the cross-sectional study, and 23 participants with RC tendinopathy were recruited for the longitudinal study. Proprioception was evaluated by an active joint-repositioning task: The upper limb was passively moved to a predetermined position, and the participant was asked to actively replicate the movement. The difference between the predetermined position and the replicated position was measured. The mean errors in positions of lateral, medial, and neutral rotation of the shoulder and the global mean error were reported. In addition to the active-repositioning assessment in the longitudinal study, symptoms and functional limitations were evaluated by the Disability of the Arm Shoulder and Hand questionnaire. RESULTS: Significant deficits in active repositioning (p < .01), independent of the position, were observed in participants with RC tendinopathy compared with controls. The DASH score was improved after rehabilitation intervention (p < .001), and patients with active-repositioning deficits at baseline had reduced repositioning error (p < .05). CONCLUSIONS: Upper limb active joint repositioning was impaired in participants with RC tendinopathy. Symptoms and functional limitations and active joint repositioning in participants with RC tendinopathy and initial deficits were improved after a 6-week global rehabilitation program.

Effects of a movement training oriented rehabilitation program on symptoms, functional limitations and acromiohumeral distance in individuals with subacromial pain syndrome.

BACKGROUND: Multiple factors have been associated with the presence of a subacromial pain syndrome (SPS), including deficits in performance of scapular and glenohumeral muscles. Such deficits can lead to inadequate kinematics and decreased acromiohumeral distance (AHD). Exercises that aim at correcting these deficits, such as movement training, were suggested to improve symptoms and functional limitations. To date, few studies have assessed outcomes following an intervention focused on movement training. OBJECTIVES: Evaluate the effects of a rehabilitation program based on movement training on symptoms, functional limitations and AHD in individuals with SPS. DESIGN: Prospective single group pre-post design. METHODS: Twenty-five participants with SPS (SPS group) participated in a 6-week program. Twenty asymptomatic volunteers were recruited for normative AHD values (control group). Outcomes of both groups were evaluated at baseline and 6 weeks, i.e. immediately following intervention for the SPS group. Changes in symptoms and functional limitations for SPS group were assessed using the Western Ontario Rotator Cuff (WORC) index and Disability of the Arm Shoulder and Hand (DASH) questionnaire. Changes in AHD for both groups were assessed using ultrasonographic measures. RESULTS: Following the rehabilitation program, the scores on WORC and DASH were significantly improved (p < 0.001). AHD increased significantly in the SPS group (p = 0.019), especially in a subgroup with initial deficits (p < 0.001). CONCLUSION: The rehabilitation program yielded improvements in symptoms and functional limitations in participants with SPS. Moreover, it led to an increase of the AHD--thus potentially decreasing subacromial compression, particularly in participants with an initially smaller AHD. The trial was registered at ClinicalTrials.gov: identifier--NCT02395770.

Alterations in central motor representation increase over time in individuals with rotator cuff tendinopathy.

OBJECTIVE: To investigate whether rotator cuff tendinopathy leads to changes in central motor representation of a rotator cuff muscle, and to assess whether such changes are related to pain intensity, pain duration, and physical disability. METHODS: Using transcranial magnetic stimulation, motor representation of infraspinatus muscle was assessed bilaterally in patients with unilateral rotator cuff tendinopathy. RESULTS: Active motor threshold is significantly larger for the affected shoulder comparatively to the unaffected shoulder (n=39, p=0.01), indicating decreased corticospinal excitability on the affected side compared to unaffected side. Further, results suggest that this asymmetry in corticospinal excitability is associated with duration of pain (n=39; r=0.45; p=0.005), but not with pain intensity (n=39; r<0.03; p>0.43). In contrast with findings in other populations with musculoskeletal pain, no significant inter-hemispheric asymmetry was observed in map location (n=16; p-values ⩾ 0.91), or in the amplitude of motor responses obtained at various stimulation intensities (n=16; p=0.83). CONCLUSION: Chronicity of pain, but not its intensity, appears to be a factor related to lower excitability of infraspinatus representation. SIGNIFICANCE: These results support the view that while cortical reorganization correlates with magnitude of pain in neuropathic pain syndromes, it could be more related to chronicity in the case of musculoskeletal disorders.