RELIABILITY OF IMPAIRMENT AND PHYSICAL PERFORMANCE-MEASURES FOR PERSONS WITH PARKINSONS-DISEASE

Background and Purpose. Parkinson's disease (PD) is characterized by r igidity, postural instability, bradykinesia, and tremor, as well as ot her musculoskeletal impairments and functional limitations. The purpos e of this investigation was to determine the reliability and stability of measures of impairments and physical performance for people in the early and middle stages of PD. Subjects. Thirteen men and 2 women in Hoehn and Yahr stages 2 and 3 of PD participated. Their mean age was 7 4.5 years (SD=5.7, range=64-84). Methods. Thirteen impairment-level va riables and 8 physical performance variables were measured. Measuremen ts were taken on two consecutive days and again a week later on the co rresponding two consecutive days. Reliability and stability were asses sed using analysis of variance and intraclass correlation coefficients (ICCs). Results. Test-retest reliability (ICCs) of variables ranged f rom .69 (hamstring muscle length) to .97 (lumbar flexion). Intraclass correlation coefficients were .85 or greater for 10 of the variables. Conclusions and Discussion. The results suggest that in the early and middle stages of PD, many of the measures of impairment and physical p erformance are relatively stable.