Effect of coordination biofeedback on (re)learning preferred postural patterns in post-stroke patients.

After stroke, ankle-hip coordination during stance is characterized by changes in the postural system dynamics, specifically the disappearance of the in-phase pattern and the reduced stability of the anti-phase pattern. This study was conducted to assess the success of a coordination visual biofeedback for the (re)learning of the two preferred patterns, and to explore the effect of this treatment on postural and functional abilities. Twenty four patients were randomly assigned to one of two experimental groups or to a control group. During one month, patients from experimental groups followed a training protocol on the two preferred postural patterns using the biofeedback device. These two groups improved their in-phase coordination after the (re)learning compared with control group, and showed a related improvement of the functional independence measure. Results suggest that (re)learning the in-phase pattern is possible and seems to improve independence in poststroke patients.

Changes in preferred postural patterns following stroke during intentional ankle/hip coordination.

We compared the spatio-temporal postural organization between stroke patients and healthy controls in a bipedal standing task where participants had to intentionally produce two specific ankle/hip coordination patterns: in-phase and anti-phase. The pattern to reproduce was visually represented by a ankle-hip Lissajous figure, and a real-time biofeedback displayed the current coordination sur-imposed to the expected coordination. Contrary to the healthy participants who were successful at reproducing the two patterns, stroke patients were unable to produce the in-phase pattern. In addition, when the anti-phase pattern was required, a reduction of stability was observed for the stroke group. The impairment of postural capacities following stroke was thus accompanied by a disappearance of one of the two preferred patterns found in healthy participants, a result that have consequences for understanding the etiology of postural pattern formation and the elaboration of rehabilitation programs.

Use of the Faces Pain Scale by left and right hemispheric stroke patients.

No pain scale is available for stroke patients due to the presence of language or cognitive disorders. However, the Faces Pain Scale (FPS), which was initially developed for children, has been used with success in adults with cognitive impairments. The aim of this study is to test whether the FPS could be used in left or right hemispheric stroke patients (LHSP, RHSP). One hundred twenty-seven stoke patients and 21 controls were recruited in 2 rehabilitation units. Construct validity of FPS was assessed by rating and ranking facial expressions. FPS was correlated to a Visual Analog Scale (VAS) and to a Verbal Rating Scale (VRS) for the assessment of shoulder pain. Reliability was determined by test-retest procedures. Performances of RHSP in the ranking and rating procedures were very poor compared to LHSP and to controls. However, in the assessment of patients' shoulder pain, FPS scores were highly correlated with VAS and VRS in both stroke groups (r=0.65-0.82, p<10(-3)). FPS was more reliable in LHSP than in RHSP. It was preferred to VAS and VRS in LHSP, while in RHSP VAS was the preferred scale. The present study provides preliminary support for the validity and the reliability of FPS in LHSP. However, we do not recommend its sole use in stroke patients. Further studies are needed to determine whether FPS can be used in stroke patients for assessing changes in severity of pain over time.