A fluidity scale for evaluating the motor strategy of the rise-to-walk task after stroke

(1) To develop an ordinal scale (content validity) for assessing fluidity of the rise-to-walk task (RTW); (2) to examine the concurrent validity of the fluidity scale; (3) to study the inter-rater reliability of the scale.

A group of physical therapists participated in the scale development (content validity); a cross-sectional design was used to study the agreement between the fluidity scale and the fluidity index (criterion measure) obtained with the instrumented method (concurrent validity) and to examine the inter-rater reliability of the scale.

Rehabilitation centre.

Nineteen persons with a chronic stroke and 19 age- and gender-matched healthy subjects.

For the validation study: the fluidity index (FI) and the scores from the fluidity scale; for the inter-rater reliability study: duration of the RTW task and fluidity scores.

The FI values did not overlap across categories of the scale and the relationship between FI values and the fluidity scores was 0.99. The weighted kappa (kappa(w)) indicated a substantial level of agreement between the new raters (kappa(w) = 0.78) and between the new raters and the expert rater (kappa(w) = 0.71). Corresponding mean intraclass correlation coefficients for the RTW duration were 0.95.

These results indicate that the descriptors of the scale provided a gradation of fluidity comparable to the gold standard measure (FI) and that trained clinicians can use the fluidity scale with a substantial level of reliability. The RTW task is a simple clinical tool for assessing mobility and motor strategies (locomotor co-ordination) in patients presenting varying degrees of motor recovery after stroke.