Purpose: The purpose of this study was to examine the heart rate and walking velocity of children with low and midlumbar myelomeningocele (MMC) using two types of orthoses.
Methods: Eight children with low and midlumbar myelomeningocele (mean age = 10.7 years) participated in the study. A clinical examination of muscle strength in the lower limbs was performed, and level of functional ambulation was defined. Weight and height were documented, and body mass index was calculated. Heart rate was recorded by a transmitter detecting heart beats, and walking time was registered as the children walked as far as possible along a straight corridor of 102 meters at a self-selected velocity. Two orthosis types were tested, each three times.
Results: All children showed higher heart rate than peers who were nondisabled. No steady-state heart rate level that could be used as a basis for calculating physiological cost index was achieved in any subject. In this study group, no difference was seen in heart rate trends with respect to the two tested orthoses. The children who were household ambulators, all with weaker hip abductors and hip extensors, walked with lower velocity than those who were community ambulators (all with stronger hip muscles). The children in the former group also walked significantly shorter distances, however, with similar heart rate.
Conclusions: Pausing when the heart rate reaches a strenuous activity level is interpreted as a solution to maintain functional walking by keeping the heart rate and thus the energy expenditure at a comfortable level.