Relationship Among Shoulder Proprioception, Kinematics, and Pain After Stroke

Objective: To identify a possible relationship among chronic poststroke shoulder pain (PSSP), scapular resting pose, and shoulder proprioception. Design: Case-control study. Setting: Rehabilitation center. Participants: A total of 21 inpatients with stroke and 10 healthy control subjects. Interventions: Not applicable. Main Outcome Measures: Orientations of both the contralateral and ipsilateral (ie, paretic and nonparetic) shoulders during rest in degrees, angular displacement (degrees) for threshold to detection of passive motion (TDPM) tests, and absolute error (degrees) for passive reproduction of joint position (PRJP) tests. Results: The contralateral shoulder of patients with PSSP showed more scapular lateral rotation and larger TDPM and PRJP scores than both patients without PSSP and control subjects. Additionally, the contralateral shoulder of patients with deteriorated proprioception showed more scapular lateral rotation than control subjects, whereas their ipsilateral shoulder showed more scapular lateral rotation than both control subjects and patients with good proprioception. Conclusions: A clear relation among affected shoulder kinematics, affected proprioception, and PSSP was found. In determining the risk of developing PSSP, attention should be paid to a patients shoulder proprioception and kinematics. If both are altered after stroke, this could worsen the initial pathology or cause secondary pathologies and thus initiate a vicious circle of repetitive soft tissue damage leading to chronic PSSP. Additionally, more attention should be paid to the ipsilateral (ie, nonparetic) shoulder because it could be used in determining the risk of developing PSSP in the contralateral (ie, paretic) shoulder.