Strength training can improve steadiness in persons with essential tremor

We evaluated the effect of a strength-training program on the ability of persons with essential tremor to exert steady forces with the index finger. Thirteen subjects with a diagnosis of essential tremor were assigned to three different groups: one group trained with heavy loads, one with light loads, and one did not perform any training. Subjects attempted to generate steady contractions during both postural and constant-force tasks. Steadiness was quantified by the root mean square amplitude of acceleration during postural tasks and the standard deviation and coefficient of variation of force during the constant-force tasks. Subjects who performed the training program with heavy loads experienced an increase in steadiness around the target force during the constant-force tasks. Subjects in the other two groups did not exhibit any changes. These findings suggest that strength training can decrease the magnitude of tremor. However, we did not observe any associated improvements in functional abilities.