Maximum weight-shifts in sitting in non-ambulatory people with stroke are related to trunk control and balance: a cross-sectional study.

BACKGROUND: Impaired sitting balance is common in persons with stroke, affecting postural control in different directions. However, studies seldomly investigate sitting balance in severely affected non-ambulatory persons with stroke and precise assessment including the diagonal directions are scarce. RESEARCH QUESTION: Are measurements of maximal voluntary weight-shifts decreased in severely affected persons with stroke in comparison to healthy controls, and is there a relationship with clinical measurements of trunk control, sitting and standing balance? METHODS: 14 Persons with stroke were recruited in the rehabilitation phase along with 32 healthy controls. A clinical pressure platform (RM Ingénierie, France) evaluated the weight-distribution during static sitting and measurements of maximal voluntary weight-shifts, by centre of pressure displacements in six directions. Clinical measurements included Trunk Control Test, Trunk Impairment Scale and Berg Balance Scale. RESULTS: The persons with stroke had a mean (SD) age of 69 (17) years, including 5 females and 9 males and were on average 57 (40) days post stroke. No patient was able to walk without manual support and median (IQR) Berg Balance Scale score was 17 (6-33) out of 56 points. Measurements showed that the centre of pressure distance was significantly smaller in all directions in persons with stroke compared to healthy controls (p < 0.05). The clinical measurements demonstrated moderate to very high correlations with centre of pressure distance in the diagonal forward, diagonal backward and lateral directions (r = 0.54 - 0.89). SIGNIFICANCE: This study reveals that measurements of maximal voluntary weight-shifts are feasible and show clinically relevant deficits in severely affected non-ambulatory persons with stroke. Especially the lateral and diagonal directions can be of interest to investigate further as they are most strongly correlated with clinical measurements of balance. Reaching exercises in these directions could be considered a core element of rehabilitation for this group of patients.

A cross-sectional study comparing lateral and diagonal maximum weight shift in people with stroke and healthy controls and the correlation with balance, gait and fear of falling.

Impaired balance is common post stroke and can be assessed by means of force-platforms measuring center of pressure (COP) displacements during static standing, or more dynamically during lateral maximum weight shift (MWS). However, activities of daily life also include diagonal MWS and since force platforms are nowadays commercially available, investigating lateral and diagonal MWS in a clinical setting might be feasible and clinically relevant. We investigated lateral and diagonal MWS while standing in patients with stroke (PwS) and healthy controls (HC), evaluated MWS towards the affected and the non-affected side for PwS and correlated MWS with measures of balance, gait and fear of falling. In a cross-sectional observational study including 36 ambulatory sub-acute inpatients and 32 age-matched HC, a force platform (BioRescue, RM Ingénierie, France) was used to measure lateral and diagonal MWS in standing. Clinical outcome measures collected were Berg Balance Scale and Community Balance and Mobility Scale (CBMS) for balance, 10-meter walk test (10MWT) for gait speed and Falls Efficacy Scale-international version for fear of falling. MWS for PwS towards the affected side was significantly smaller compared to HC (lateral: p = 0.029; diagonal-forward: p = 0.000). MWS for PwS was also significantly reduced towards the affected side in the diagonal-forward direction (p = 0.019) compared to the non-affected side of PwS. Strong correlations were found for MWS for PwS in the diagonal-forward direction towards the affected side, and clinical measures of balance (CBMS: r = 0.66) and gait speed (10MWT: r = 0.66). Our study showed that ambulatory sub-acute PwS, in comparison to HC, have decreased ability to shift their body weight diagonally forward in standing towards their affected side. This reduced ability is strongly related to clinical measures of balance and gait speed. Our results suggest that MWS in a diagonal-forward direction should receive attention in rehabilitation of ambulatory sub-acute PwS in an inpatient setting.