Amount and intensity of daily living activities in Charcot-Marie-Tooth 1A patients

Background: Charcot-Marie-Tooth 1A (CMT1A) patients show a reduction of spontaneous activities of daily living measured by means of questionnaires or pedometers, which are quite inaccurate compared to recent measurement techniques. Aim: The study aimed at quantifying daily living activities in CMT1A patients by means of inertial sensors, which give information not only on the amount but also on the intensity of these activities. Materials and methods: Time and count (amount), and velocity and power (intensity) of 24 h daily living activities were measured in eight patients (20-48 years; Barthel > 90; Tinetti > 20) and eight healthy individuals, matched for age and gender, by means of a wearable inertial sensor device. Results: There were no differences between patients and controls in the 24-h distance covered and count of steps. However, count of step climbing and sit to stand were lower in patients than in controls (139.93 +/- 141.66 vs. 341.06 +/- 164.07 n and 58.23 +/- 7.82 vs. 65.81 +/- 4.75 n, respectively; P < 0.05) as well as mean daily step-climbing and walking velocities (1.07 +/- 0.17 vs. 1.21 +/- 0.10 m/sec and 1.16 +/- 0.31 vs. 1.87 +/- 0.50 m/sec, respectively; P < 0.05). In CMT1A patients there was a positive correlation between strength of the knee extensor muscles and both count of steps climbed (R = 0.80) and sit to stand (R = 0.79). Discussion and conclusion: The reduced ability of CMT1A patients to carry out activities at high intensity, which was correlated with strength, suggests that strength training might be a rehabilitation tool for improving the 1 ability to carry out these activities.