ABSTRACT
PURPOSE: To compare the physical activity of a group of children with mitochondrial myopathy (MM) with children who are healthy and to evaluate the suitability of different measurement tools. METHODS: The physical activity of 6 children with MM and 10 children who are healthy was measured using accelerometry, heart rate monitoring, video observation, rating of their fatigue, and 2 questionnaires about their physical activity and quality of life. RESULTS: The children with MM spent less time in moderate to vigorous activity, and their activity level measured with the accelerometer was lower than the children who are healthy. Also, the children with MM indicated a higher level of fatigue and a lower quality of life. CONCLUSIONS: Children with MM are on average less physically active, report a higher level of fatigue, and a lower quality of life than children who are healthy.
Subject(s)
Mitochondrial Diseases/physiopathology , Mitochondrial Diseases/rehabilitation , Motor Activity/physiology , Physical Therapy Modalities , Accelerometry , Child , Fatigue , Female , Heart Rate , Humans , Male , Quality of Life , Videotape RecordingABSTRACT
Functional electrical stimulation (FES) enables restoration of movement in individuals with spinal cord injury. FES-based devices use electric current pulses to stimulate and excite the intact peripheral nerves. They produce muscle contractions, generate joint torques, and thus, joint movements. Since the underlying neuromuscular-skeletal system is highly nonlinear and time-varying, feedback control is necessary for accurate control of the generated movement. However, classical feedback/closed-loop control algorithms have so far failed to provide satisfactory performance and were not able to guarantee stability of the closed-loop system. Because of this, only open-loop controlled FES devices are in clinical use in spite of their limitations. The purpose of the reported research was to design a novel closed-loop FES controller that achieves good tracking performance and guarantees closed-loop stability. Such a controller was designed based on a mathematical neuromuscular-skeletal model and is founded on a sliding mode control theory. The controller was used to control shank movement and was tested in computer simulations as well as in actual experiments on healthy and spinal cord injured subjects. It demonstrated good robustness, stability, and tracking performance properties.
