Restoration of weight-shifting capacity in patients with postacute stroke: a rehabilitation cohort study.
OBJECTIVE
To identify and interrelate recovery characteristics of voluntary weight shifting after stroke and to examine whether the assessment of weight shifting adds information about balance recovery compared with the assessment of quiet standing.


METHODS
Exploratory study using an inception cohort with findings related to reference values from healthy elderly persons.


METHODS
Dutch rehabilitation center.


METHODS
Thirty-six inpatients (mean age, 61.8 y; mean time poststroke, 10 wk) with a first hemispheric intracerebral infarction or hematoma who were admitted to retrain standing balance and walking.


METHODS
Individualized therapy.


METHODS
Center of pressure (COP) displacements were registered during voluntary frontal-plane weight shifting guided by visual COP feedback using a dual-plate force platform. Besides the speed (number of weight shifts) and imprecision (normalized average lateral COP displacement per weight shift), the weight-transfer time asymmetry and the spatiotemporal distribution were determined. Assessments took place as soon as patients could stand unassisted for at least 30 seconds and at 2, 4, 8, and 12 weeks later.


RESULTS
During the 12-week training period, the stroke patients increased both their speed (2.3 hits/30 s; 95% confidence interval [CI], 1.1-3.4) and precision (37.7 mm/hit; 95% CI, 10.4-65.0) of weight shifting. Although the speed appeared to stabilize at a suboptimal level after 8 weeks, precision reached normal reference values after 12 weeks. Both older age (>/=65 y) and the presence of visuospatial hemineglect negatively affected weight-shifting speed but not its relative improvement in time. During the training period, a small degree of weight-transfer time asymmetry persisted (mean change, .07; 95% CI, -.21 to .36), with an average of 23% slower weight shifts toward the paretic leg, but the spatiotemporal distribution remained symmetrical. The correlations between weight-shifting and quiet-standing control at the end of training were moderate (Spearman rho range, .50-.77).


CONCLUSIONS
Even subjects with severe stroke who are selected for inpatient rehabilitation are able to improve their speed and precision of weight shifting by reducing the weight-transfer time toward both legs in a proportionate manner. The observed correlations between weight shifting and quiet standing indicate that the assessment of weight-shifting capacity provides unique information about balance recovery after stroke.
de Haart
Mirjam
M
Department of Rehabilitation Medicine, University Medical Center, St. Radboud, Nijmegen, The Netherlands.
Geurts
Alexander C
AC
Dault
Mylène C
MC
Nienhuis
Bart
B
Duysens
Jacques
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation