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Background and Purpose. Adults with cerebral palsy (CP) are at risk for decreased mobility and health complications, and exercise may combat some of these negative changes. Because people with CP have difficulty generating sufficient muscle force, exercise augmented with functional electrical stimulation (FES) is an option for increasing exercise intensity. This mixed-method (quantitative-qualitative) case report describes the effects--across the International Classification of Functioning, Disability and Health (ICF) model--of cycling with FES (FES cycling) in an adult with CP. Case Description. An ambulatory 49-year-old man with spastic diplegic CP cycled with FES at home for 30 minutes, 3 times per week, for 12 weeks. Volitional efforts were augmented by FES of the bilateral quadriceps, gastrocnemius, and gluteal muscles. Testing was performed before and after the intervention and 4 weeks after intervention withdrawal. Outcomes. After training, quadriceps muscle strength (force-generating capacity) improved by 22.2%, hamstring muscle strength improved by 18.5%, and the Timed 'Up & Go' Test time decreased from 11.9 to 9.0 seconds. The patient reported increased performance and satisfaction for self-identified goals at the ICF level of participation, and his score on the Medical Outcomes Study 36-Item Health Survey questionnaire increased from 62.1 to 77.6. However, he reported increased back pain, which he attributed to positioning while cycling. Qualitative interviews provided context (the patient's perspective) for some of the quantitative results. Discussion. The patient made gains in body structure and function, activity, and participation (ICF levels) after FES cycling. The mixed-method approach provided insight into his experiences and perceptions about the measures assessed quantitatively. Further investigation on FES cycling in this population as well as positioning during cycling is warranted., Fitness levels of people with disabilities have gained attention through Healthy People 2010, a focus of which is secondary conditions of disability and increasing physical fitness. (1) Inactivity in people [...]

Individuals with physical disabilities may benefit from cycling interventions, which could address impairments while potentially minimizing stress on joints. Improvements in impairments may then have an impact on mobility, activity, and participation. Cycling studies with adults and children who are healthy have shown that many factors can influence the biomechanics of cycling. These factors include seat height, crank arm length, foot position, cadence, and workload. Knowledge of these factors is important for rehabilitation professionals who prescribe cycling as an intervention for individuals with disabilities, because changing these factors can potentially influence the therapeutic outcomes. In addition, further research is needed to fully understand the effect of these factors on individuals with disabilities., Individuals with physical disabilities may benefit from cycling interventions, which could address impairments such as decreased muscle strength (force-producing capacity), range of motion, and fitness while potentially minimizing stress to [...]

Background and Purpose The purpose of this study was to compare the biomechanics of recumbent cycling between adolescents with cerebral palsy (CP) classified at Gross Motor Function Classification System (GMFCS) levels III and IV and adolescents with typical development (TD). Subjects Twenty subjects, ages ([bar.x] ± SD) 15.2 ± 1.6 years (10 with TD, 10 with CP), participated. Methods Lower-extremity kinematics and muscle activity were measured at 30 and 60 rpm while subjects pedaled on a recumbent cycle. Energy expenditure and perceived exertion were measured during a 5-minute test, and efficiency was calculated. Noncircular data were analyzed with analyses of variance. Circular data were analyzed using circular t tests. Results Differences were found between groups for joint kinematics for all motions. Subjects with CP displayed earlier onsets and later offsets of muscle activity, increased co-contraction of agonist and antagonist muscles, and decreased efficiency compared with subjects with TD. There were no differences in perceived exertion. Discussion and Conclusion Differences in cycling biomechanics between children with CP and children with TD may be due to decreased strength and motor control in the children with CP., Children with cerebral palsy (CP) typically have progressive impairments that affect their function as children and later as adults, and they have decreased fitness levels versus children with typical development [...]

Background and Purpose. Following spinal cord injury (SCI), paralyzed muscles undergo physiological changes that alter their force responses to electrical stimulation. The purpose of this study was to investigate the effects of SCI on the contractile properties and force-frequency relationship (FFR) of the paralyzed human quadriceps femoris muscle of adolescents and young adults. Subjects. Thirteen subjects (11 male, 2 female; age range=11-24 years) with motor complete SCIs and 13 matched control subjects (11 male, 2 female; age range=9-23 years) without SCI participated in the study. Methods. Both groups of subjects underwent the same testing protocol using similar equipment. Results. The paralyzed muscles of the subjects with SCI produced 62% of the peak twitch force and had a fatigue ratio that was 65% of that of the control subjects. The paralyzed muscles contracted 14% and 25% faster and relaxed 38% and 46% faster than the nonparalyzed muscles in nonfatigued and fatigued conditions, respectively. Compared with the control subjects, the subjects with SCI had twitch-to-tetanus ratios that were 84% and 127% greater in nonfatigued and fatigued conditions, respectively. Relative to the control subjects, the FFR of the subjects with SCI was shifted to the left in the fatigued condition. Relative to their respective nonfatigued conditions, the FFR of both groups of subjects shifted to the right with fatigue. Discussion and Conclusion. These findings may have important implications for designing stimulation strategies to reduce the rapid fatigue that limits the clinical efficacy of functional electrical stimulation. [Scott WB, Lee SCK, Johnston TE, et al. Contractile properties and the force-frequency relationship of the paralyzed human quadriceps femoris muscle. Phys Ther. 2006;86:788-799.] Key Words: Electrical stimulation, Muscle fatigue, Muscle performance, Muscle weakness, Muscular atrophy, Paralysis, Spinal cord injuries., Electrical stimulation of paralyzed skeletal muscle can be used to assist people with spinal cord injury (SCI) in performance of functional movements. (1) This therapeutic intervention is called functional electrical [...]