ACCURACY OF OBSERVATIONAL KINEMATIC ASSESSMENT OF UPPER-LIMB MOVEMENTS

Background and Purpose. This study investigated the accuracy of physic al therapists' visual judgments about kinematic features of the upper- limb movements of people without neurological impairments and people w ith neurological impairments following a cerebrovascular accident (CVA ). Subjects. Ten experienced physical therapists served as observers. Eleven people with a primary diagnosis of cortical or subcortical CVA and 4 older individuals without neurological impairments participated as ''performers.'' Methods. The performers were videotaped as they com pleted a transport task. Three videotapes were edited to form three ph ysical scales of peak movement speed,jerkiness, and hand path indirect ness. On two occasions, therapists viewed these videotapes and made ju dgments about each performance on visual analog scales. Therapists' vi sual judgments were then compared with criterion measures determined b y three-dimensional instrumented analysis. Results. The accuracy of th e therapists' judgments was investigated using regression methods. The rapists were able to make moderately to highly accurate judgments of m ovement speed (r greater than or equal to.87), jerkiness (r greater th an or equal to.78), and hand path indirectness (r greater than or equa l to.68). These judgments remained highly stable over time (r greater than or equal to.82). Differences in therapists' judgment models, evid ent from slope and intercept variability in the regression models, wer e reflected in lower intertherapist agreement (intraclass correlation coefficients=.65-.85). Conclusion and Discussion. Experienced physical therapists accurately and reliably judged kinematic aspects of perfor mance using observational assessment. Observational kinematic assessme nt warrants further systematic investigation.