Objective: To examine physical activity and the relationships to measures of function and disease severity in individuals with CMT1A.
Background: Physical activity has been reported to be reduced in individuals with CMT and as a measure of function, it may serve as an important endpoint for clinical trials. Physical activity has been measured using many different wearable devices that produce variables such as the time spent in various positions as well as the number of steps taken per day.
Methods: Participants were asked to wear BioStamp MC-10 sensors during assessments of mobility during an in-person research visit and then for the following 24 hours. These small, flexible sensors were applied using adhesive at the chest, thigh and lower leg. Data captured regarding the time spent resting, moving, and sleeping as well as the number of steps taken was recorded. Physical activity variables were compared to the CMT-Functional Outcome Measure (CMT-FOM) and measures of disease severity including strength and the CMT Exam Score (CMTES).
Results: 15 individuals (67% females) between the ages of 18-64 (mean age 37.3) participated in this study. Individuals moved a mean time of 150 minutes/day and rested a mean 781 minutes/day. Individuals took an average of 4416 steps/day. The number of steps was significantly correlated with the CMT-FOM (ρ=-0.71; p=0.003) and overall lower extremity strength (ρ=0.54; p=0.04).
Conclusions: Physical activity, as measured by the number of steps taken, using adhesive wearable devices was associated with in-person measures of strength and function. Future studies of longer duration are needed to further examine physical activity as an endpoint for future clinical trials.