The hypothesis of overwork weakness in Charcot-Marie-Tooth: a critical evaluation.

OBJECTIVE: It has been reported that the non-dominant hand of patients with Charcot-Marie-Tooth disease is stronger than the dominant hand as a result of overwork weakness. The objective of this study was to determine if this hypothesis could be verified in our population.

DESIGN: Survey.

SUBJECTS: Twenty-eight patients with Charcot-Marie-Tooth disease type I or II from a rehabilitation department of a university hospital in the Netherlands.

METHODS: The strength of 3 intrinsic muscle groups of the dominant and non-dominant hand were determined using the Medical Research Council scale and the Rotterdam Intrinsic Hand Myometer. Furthermore, grip strength, pinch and key grip strength were measured.

RESULTS: We found no differences in muscle strength for the dominant and non-dominant hand, except for a stronger key grip strength of the dominant hand in patients with Charcot-Marie-Tooth disease type II.

CONCLUSION: In our population, the dominant hand of patients with Charcot-Marie-Tooth disease type I and II was equally strong as the non-dominant hand, suggesting that there is no presence of overwork weakness in the dominant hand in our group of patients. This implies that patients with Charcot-Marie-Tooth disease do not have to limit the use of their hands in daily life in order to prevent muscle strength loss.