Hemiplegic shoulder pain affects ipsilesional aiming movements after stroke: a cross-sectional study

Hemiplegic shoulder pain (HSP) is common after stroke. The pain perception may exacerbate changes in the motor behavior of the ipsi-lesional upper limb, contributing to the functional decline of an individual's motor performance.

This study evaluates the influence of pain perception on the aiming movements performed with the ipsilesional upper limb in individuals with unilateral chronic stroke.

A cross-sectional study was conducted with 41 participants divided into three groups: 1) stroke with contralesional shoulder pain ≥ 3 by the Visual Numerical Pain Scale (SPSG; n = 13); 2) stroke no shoulder pain (nSPSG; n = 14); and 3) healthy control (CTG; n = 14) matched by sex and age. Individuals with stroke were matched for the severity of sensorimotor impairment by the Fugl-Meyer upper limb subscale and the injured hemisphere side. Stroke groups performed aiming movements with the ipsilesional upper limb and the CTG with the corresponding limb using a pen tip on the sensitive surface of a digitizing tablet. Performance across groups was compared by one-way analysis of variance, considering the time since injury as a covariate. The planning and execution variables of the movement trajectory were analyzed, and the significance was set at 5%.

Trajectories of the SPSG were slower (p = .010; η² = 0.22), were less smooth (p = .002; η² = 0.30), had more directional error (p = .002; η² = 0.28), and were less accurate (p = .034; η² = 0.17) than the CTG. The nSPSG and CTG showed similar performance.

The perception of pain impairs aiming movements performed with the ipsilesional upper limb in individuals with unilateral chronic stroke.