Abstract.Objective: To compare the Timed "Up and Go" and Functional Reach tests to the Berg Balance Scale for concurrent validity in a broad adult population. Design: A prospective study of individuals with balance deficits. Setting: Neurological rehabilitation, skilled nursing, and acute care facilities. Subjects: Twenty subjects: 12 females and eight males, aged 38 to 86 years (µ=68, SD=14.5). Intervention: The order in which the three tests were performed on each subject was randomized and the scores from the three tests were analyzed using correlation coefficients. Main Outcome Measures: Balance and correlations were based on scores from each of the three balance tests performed.

Electrical stimulation of the quadriceps muscle was used to elicit 4-min isometric contractions at 10% of the maximal voluntary contraction (MVC) in four male and three female subjects. The effect of four waveforms, including Russian, interferential, sine, and square, on the mean stimulation current required to achieve the desired contraction force, subjective comfort, and physiological responses was studied. Interferential stimulation, even at full power, could not elicit a sustained contraction at 10% MVC. The contractions elicited by electrical stimulation utilizing the sine waveform required significantly less mean stimulation current to maintain the desired force of contraction with consistently lower verbal rating scale scores and greater increases in oxygen consumption than either the Russian or square waveform stimulations. Russian waveform stimulation produced a significantly greater rise in galvanic skin resistance than the sine or square waveform while the changes in respiratory quotient were similar between waveforms. The data support sine wave stimulation as working the best by producing the desired muscle tension with the least mean stimulation current and therefore, the least tissue trauma while providing the most subjective comfort.