Determinants of Frame Running Capacity in Athletes With Cerebral Palsy to Improve Training Routines and Classification Strategies: A Cross-sectional Observational Study.

OBJECTIVES: The aim of the study were to (1) investigate what physical and physiological parameters are most important for Frame Running capacity, a parasport for individuals with ambulatory difficulties, and (2) determine whether Frame Running capacity can be predicted in athletes with cerebral palsy. DESIGN: Athletes with cerebral palsy ( N = 62, Gross Motor Classification System I-V; 2/26/11/21/2) completed a 6-min Frame Running test. Before the 6-min Frame Running test, muscle thickness, passive range of motion (hip, knee, ankle), selective motor control, and spasticity (hip, knee, ankle) were measured in both legs. In total, 54 variables per individual were included. Data were analyzed using correlations, principal component analysis, orthogonal partial least square regression, and variable importance in projection analysis. RESULTS: The mean 6-min Frame Running test distance was 789 ± 335 m and decreased with motor function severity. The orthogonal partial least square analysis revealed a modest degree of covariance in the variables analyzed and that the variance in the 6-min Frame Running test distance could be predicted with 75% accuracy based on all the variables measured. Variable importance in projection analysis indicated hip and knee extensor spasticity (negative effect), and muscle thickness (positive effect) arose as the most important factors contributing to Frame Running capacity. CONCLUSIONS: These results are an important resource to enable optimization of training regimes to improve Frame Running capacity and contribute to evidence-based and fair classification for this parasport.

Extracellular vesicle characteristics and microRNA content in cerebral palsy and typically developed individuals at rest and in response to aerobic exercise.

In this study, the properties of circulating extracellular vesicles (EVs) were examined in cerebral palsy (CP) and typically developed (TD) individuals at rest and after aerobic exercise, focusing on the size, concentration, and microRNA cargo of EVs. Nine adult individuals with CP performed a single exercise bout consisting of 45 min of Frame Running, and TD participants completed either 45 min of cycling (n = 10; TD EX) or were enrolled as controls with no exercise (n = 10; TD CON). Blood was drawn before and 30 min after exercise and analyzed for EV concentration, size, and microRNA content. The size of EVs was similar in CP vs. TD, and exercise had no effect. Individuals with CP had an overall lower concentration (∼25%, p < 0.05) of EVs. At baseline, let-7a, let-7b and let-7e were downregulated in individuals with CP compared to TD (p < 0.05), while miR-100 expression was higher, and miR-877 and miR-4433 lower in CP compared to TD after exercise (p < 0.05). Interestingly, miR-486 was upregulated ∼2-fold in the EVs of CP vs. TD both at baseline and after exercise. We then performed an in silico analysis of miR-486 targets and identified the satellite cell stemness factor Pax7 as a target of miR-486. C2C12 myoblasts were cultured with a miR-486 mimetic and RNA-sequencing was performed. Gene enrichment analysis revealed that several genes involved in sarcomerogenesis and extracellular matrix (ECM) were downregulated. Our data suggest that circulating miR-486 transported by EVs is elevated in individuals with CP and that miR-486 alters the transcriptome of myoblasts affecting both ECM- and sarcomerogenesis-related genes, providing a link to the skeletal muscle alterations observed in individuals with CP.

RaceRunning training improves stamina and promotes skeletal muscle hypertrophy in young individuals with cerebral palsy.

BACKGROUND: Individuals with cerebral palsy (CP) are less physically active, spend more time sedentary and have lower cardiorespiratory endurance as compared to typically developed individuals. RaceRunning enables high-intensity exercise in individuals with CP with limited or no walking ability, using a three-wheeled running bike with a saddle and a chest plate for support, but no pedals. Training adaptations using this type of exercise are unknown. METHODS: Fifteen adolescents/young adults (mean age 16, range 9-29, 7 females/8 males) with CP completed 12 weeks, two sessions/week, of RaceRunning training. Measurements of cardiorespiratory endurance (6-min RaceRunning test (6-MRT), average and maximum heart rate, rate of perceived exertion using the Borg scale (Borg-RPE)), skeletal muscle thickness (ultrasound) of the thigh (vastus lateralis and intermedius muscles) and lower leg (medial gastrocnemius muscle) and passive range of motion (pROM) of hip, knee and ankle were collected before and after the training period. RESULTS: Cardiorespiratory endurance increased on average 34% (6-MRT distance; pre 576 ± 320 m vs. post 723 ± 368 m, p < 0.001). Average and maximum heart rate and Borg-RPE during the 6-MRT did not differ pre vs. post training. Thickness of the medial gastrocnemius muscle increased 9% in response to training (p < 0.05) on the more-affected side. Passive hip flexion increased (p < 0.05) on the less-affected side and ankle dorsiflexion decreased (p < 0.05) on the more affected side after 12 weeks of RaceRunning training. CONCLUSIONS: These results support the efficacy of RaceRunning as a powerful and effective training modality in individuals with CP, promoting both cardiorespiratory and peripheral adaptations.