ISOKINETIC TESTING OF ANKLE STRENGTH IN OLDER ADULTS - ASSESSMENT OF INTERRATER RELIABILITY AND STABILITY OF STRENGTH OVER 6 MONTHS

The study purposes were (1) to estimate the inter-rater reliability of isokinetic strength tests at the ankle in older adults (test-retest i nterval of three to 7 days), and to determine whether more experienced examiners were more reliable; and (2) to estimate 6 month stability o f strength tests. Inter-rater reliability was high for plantar flexion and dorsiflexion tests where average strength was more than about 10 Newton-meters (Nm) (Pearson R = 0.87-0.95). When average strength was less than 10Nm, reliability was less (R = 0.42-0.75). Experienced exam iners (physical therapists) and less experienced examiners (research a ssistants) were equally reliable. Variability in strength over 6 month s was no greater than variability over a few days. We conclude that is okinetic tests of ankle strength in older adults are highly reliable a nd stable when examiners are adequately trained and subjects maintain usual physical activity levels. (C) 1994 by the American Congress of R ehabilitation Medicine and the American Academy of Physical Medicine a nd Rehabilitation