Strength training can improve steadiness in persons with essential tremor

We evaluated the effect of a strength-training program on the ability of pe rsons with essential tremor to exert steady forces with the index finger. T hirteen subjects with a diagnosis of essential tremor were assigned to thre e different groups: one group trained with heavy loads, one with light load s, and one did not perform any training. Subjects attempted to generate ste ady contractions during both postural and constant-force tasks. Steadiness was quantified by the root mean square amplitude of acceleration during pos tural tasks and the standard deviation and coefficient of variation of forc e during the constant-force tasks. Subjects who performed the training prog ram with heavy loads experienced an increase in steadiness around the targe t force during the constant-force tasks. Subjects in the other two groups d id not exhibit any changes. These findings suggest that strength training c an decrease the magnitude of tremor. However, we did not observe any associ ated improvements in functional abilities. (C) 2000 John Wiley & Sons, Inc.