RELIABILITY OF MEASURING VOLUNTARY STRENGTH AND ISOMETRIC TWITCH PROPERTIES IN THE ANKLE MUSCLES OF VERY OLD ADULTS

The purpose of this study was to assess the reliability of measuring v oluntary isometric strength, evoked isometric twitch properties (peal: torque, time to peak torque, half-relaxation time), M-wave amplitude, and passive tension in very old adults (73-92 years). I;ive male and 5 female subjects were tested on two different test occasions that wer e 1 week apart. Using the intraclass correlation coefficient (ICC) met hod, the mean reliability coefficient of all measurements on the dorsi flexor (DF) and plantar flexor (PF) muscle groups was .91+/-.05. Simil ar ICC values were found for DI; and PF muscles (.92 +/-.04 and .90+/- .05, respectively). Resting PF half-relaxation time was the least reli able measure, with an ICC value of.80, while maximum voluntary strengt h was the most reliable with ICC values of.98 for DF and.97 for PF. Th e variation ranged from 0.2 to 12.3%. It was concluded that ankle musc le function (both voluntary and evoked) can be reliably assessed in th is very old age group.