Reduced elbow muscle strength in children and adolescents with Charcot-Marie-Tooth disease: a case control study

Charcot-Marie-Tooth disease type 1 (CMT1) is a prevalent inherited neuropathy characterized by progressive sensory and motor deficits affecting the peripheral nervous system. Although muscle weakness is commonly seen in the hands, weakness of more proximal muscles has been observed in adults. In childhood, the muscle strength of the upper limbs must be explored to understand the natural history of the disease.

This study assessed differences in the muscle strength of elbow flexors and extensors between typically developing children and adolescents (as controls) and those with CMT1 using isometric and isokinetic contractions.

Eighteen children and adolescents with CMT1 participated and were matched with 36 controls in this case control study (1:2). The peak torque of elbow flexors (EFL) and extensors (EEX) was assessed using an isokinetic dynamometer through isometric and isokinetic contractions at a speed of 120°.s-¹. Descriptive, t-tests and ANOVA were used for the statistical analysis.

The CMT group exhibited significantly lower peak torque values across all assessed muscles and contraction types compared to the control group (p ≤ 0.05). Additionally, the isokinetic peak torque comparing the values of the elbow flexors with elbow extensors showed a significant difference to the control group (p ≤ 0.05). The intra-group analysis considering types of contractions showed no statistical difference.

Children with CMT1 presented proximal weakness in the muscles of the upper limbs, not only in the distal hand muscles. Health professionals should pay attention to the assessment and rehabilitation procedures with the aim of contributing to quality of life in the subsequent stages of life.