Comparison of cardiac autonomic modulation of athletes and non-athletes individuals with spinal cord injury at rest and during a non-immersive virtual reality task.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To compare cardiac autonomic modulation of individuals with spinal cord injury (SCI) that practice different amounts of moderate to vigorous physical activity (PA) and able-bodied controls at rest and during a non-immersive Virtual Reality task. SETTING: Athletes with SCI of wheelchair basketball, wheelchair tennis, wheelchair handball, WCMX (wheelchair motocross), and para-swimming were assessed at the Faca na Cadeira Institute, ICEL and Clube Espéria in São Paulo, Brazil; non-athletes with SCI and able-bodied controls were assessed at the Acreditando Centro de Recuperação Neuromotora, São Paulo, Brazil. METHODS: One-hundred forty-five individuals were assessed: 36 athletes with traumatic SCI (41.1 ± 16.8 years old), 52 non-athletes with traumatic SCI (40.2 ± 14.1 years old), and 57 able-bodied individuals (39.4 ± 12.5 years old). Cardiac autonomic modulation was assessed through heart rate variability (HRV) measured in the sitting position at rest and during a VR game activity. RESULTS: We found significantly more favourable HRV for athletes with SCI when compared to non-athletes with SCI, but no differences between athletes with SCI and able-bodied controls. In addition, athletes and able-bodied controls showed adequate autonomic nervous system (ANS) adaptation (rest versus physical activity in VR), i.e., they experienced parasympathetic withdrawal during VR physical activity, which was not found in non-athletes with SCI. CONCLUSION: The practice of moderate to vigorous physical activity is associated with healthier cardiac autonomic modulation in adults with SCI, which may lead to more favourable health outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04618003, retrospectively registered.

Brake response time between male drivers with and without paraplegia: Association between sociodemographic, motor and neurological characteristics.

Objective: The objective of this study was to compare the brake response time of drivers with paraplegia (who use hand control) with drivers without paraplegia (who use their feet) in a virtual driving simulator brake test. Additionally, we aimed to predict and evaluate the association of virtual brake response time with sociodemographic, motor and cognitive variables.Methods: 40 male adult drivers, with paraplegia (n = 20, mean age 38.1 ± 3.6 years) and without paraplegia (n = 20, mean age 38.0 ± 5.8 years), with valid driver licenses, had their brake response time evaluated in an automatic transmission car simulator. Non-disabled drivers were tested with conventional foot controls, while paraplegic drivers used hand controls. Drivers with paraplegia performed simple, choice and go/no-go reaction time tests as neuropsychological evaluations. Student's t-test was used to examine the differences of driving simulator brake response time between groups. Pearson coefficient verified the correlation of driving simulator brake response time with years of driving, length of disability, handgrip strength and neuropsychological tests of the paraplegic drivers. A regression model was developed to describe the mean of driving simulator brake response time using the backward elimination method for model adjustment selecting the explanatory variables.Results: Differences of simulator brake response time between groups were not statistically significant (non-paraplegic drivers = 0.90 seconds; paraplegic drivers = 0.92 seconds, p > 0.05). Years of driving significantly correlates with brake response time of paraplegic driver (r= -58, p = 0.009). Linear regression analyses indicated that years of schooling and years of driving (explanatory variables) explained 60.2% of driving simulator brake response time for the drivers with paraplegia. Driving simulator brake response time showed no difference between drivers with and without paraplegia. Years of driving and schooling were the main predictors of braking performance in drivers with paraplegia measured in a driving simulator.

Relationship Between Power Output and Speed-Related Performance in Brazilian Wheelchair Basketball Players.

This study aimed to investigate the association between the optimum power load in the bench press (BP), shoulder press (SP), and prone bench pull (PBP) exercises and acceleration (ACC) and speed performances in 11 National Team wheelchair basketball (WB) players with similar levels of disability. All athletes were previously familiarized with the testing procedures that were performed on the same day during the competitive period of the season. First, athletes performed a wheelchair 20-m sprint assessment and, subsequently, a maximum power load test to determine the mean propulsive power (MPP) in the BP, SP, and PBP. A Pearson product-moment correlation was used to examine the relationships between sprint velocity (VEL), ACC, and the MPP in the three exercises. The significance level was set as p < .05. Large to very large significant associations were observed between VEL and ACC and the MPP in the BP, SP, and PBP exercises (r varying from .60 to .77; p < .05). The results reveal that WB players who produce more power in these three exercises are also able to accelerate faster and achieve higher speeds over short distances. Given the key importance of high and successive ACCs during wheelchair game-related maneuvers, it is recommended that coaches frequently assess the optimum power load in BP, SP, and PBP in WB players, even during their regular training sessions.

Effects of Inspiratory Muscle Training With Progressive Loading on Respiratory Muscle Function and Sports Performance in High-Performance Wheelchair Basketball Athletes: A Randomized Clinical Trial.

PURPOSE: To evaluate the effects of inspiratory muscle training associated with interval training on respiratory muscle strength and fatigue and aerobic physical performance (PP) in high-performance wheelchair basketball athletes. METHODS: Blinded, randomized clinical trial with 17 male wheelchair basketball players, randomized into control group (CG; n = 8) and training group (TG; n = 9). Respiratory muscle strength was evaluated by measuring maximal inspiratory and expiratory pressures (MIP and MEP), aerobic PP by the Yo-Yo test for wheelchair, and recovery of inspiratory muscle fatigue was assessed at 1, 5, 10, and 15 minutes after exercise test. TG performed inspiratory muscle training protocol with incremental loading for 12 weeks with 50%, 60%, and 70% of MIP, while CG performed with load 15% of MIP. RESULTS: After training period, CG presented a significant increase in MIP and MEP (P ≤ .05), with no change in aerobic PP (P ≥ .05). TG showed a significant increase for all variables (≤.05). MIP showed a large effect size for CG (1.00) and TG (1.35), while MEP showed a moderate effect for CG (0.61) and TG (0.73); distance covered had a moderate effect size for TG (0.70). For recovery of inspiratory muscle strength, CG did not present differences, while TG recovered in 10 minutes (≤.05), representing 87% of the pretest value. Positive and significant correlation between MIP and distance (.54; P ≤ .05) was observed. CONCLUSION: Inspiratory muscle training protocol with progressive loading was more effective for increasing aerobic PP and maximal inspiratory strength recovery.

The effects of motor adaptation on ankle isokinetic assessments in older drivers.

OBJECTIVES: This study sought to analyze the extent of motor adaptation in ankle plantar flexors and dorsiflexors among older drivers during clinical isokinetic testing. METHODS: One hundred older adults (70.4±5.7 years) participated in two bilateral ankle plantar flexor and dorsiflexor isokinetic assessments at 30°/sec. Peak torque (PTQ), PTQ adjusted for body weight (PTQ/BW), and total work (TW) were analyzed. RESULTS: On the dominant side, PTQ/BW and TW were significantly greater for the second plantar flexion test than were those for the first such test (p<0.001), whereas PTQ, PTQ/BW, and TW (p<0.001) were significantly greater for the second dorsiflexion test than were those for the first such test. On the non-dominant side, plantar flexion PTQ and TW were significantly lower for the second test than were those for the first test (p<0.001). CONCLUSION: Older drivers demonstrated better performance with the dominant limb on the second test. The low variability in test execution showed the existence of a motor adaptation effect for the tested movements, despite the short recovery period between the assessments.

The effects of motor adaptation on ankle isokinetic assessments in older drivers

OBJECTIVES: This study sought to analyze the extent of motor adaptation in ankle plantar flexors and dorsiflexors among older drivers during clinical isokinetic testing. METHODS: One hundred older adults (70.4±5.7 years) participated in two bilateral ankle plantar flexor and dorsiflexor isokinetic assessments at 30°/sec. Peak torque (PTQ), PTQ adjusted for body weight (PTQ/BW), and total work (TW) were analyzed. RESULTS: On the dominant side, PTQ/BW and TW were significantly greater for the second plantar flexion test than were those for the first such test (p<0.001), whereas PTQ, PTQ/BW, and TW (p<0.001) were significantly greater for the second dorsiflexion test than were those for the first such test. On the non-dominant side, plantar flexion PTQ and TW were significantly lower for the second test than were those for the first test (p<0.001). CONCLUSION: Older drivers demonstrated better performance with the dominant limb on the second test. The low variability in test execution showed the existence of a motor adaptation effect for the tested movements, despite the short recovery period between the assessments.

Trunk Function Correlates Positively with Wheelchair Basketball Player Classification.

OBJECTIVE: The aims of this study were (1) to identify differences in trunk muscle strength and balance among various classes of wheelchair basketball (WCB) players and (2) to determine if trunk muscle strength and balance correlate with the current observation-based classification of WCB players. DESIGN: Isometric trunk strength and balance (limits of stability) were objectively quantified in 42 male WCB players. Principal component analysis was used to synthesize a battery of strength and balance measures into a single, composite score of trunk function. The K-means clustering algorithm was then used to generate an objective classification system by stratifying players into 4 classes based on their trunk function. RESULTS: Results indicated that there were significant differences in trunk muscle strength and balance between various classes of WCB players (P < 0.05), such that the mean peak trunk extensor and flexor torque and limits of stability indices increased progressively according to the players' classes. There was also a significant correlation between observation-based WCB classification and principal component analysis cluster analysis-based WCB classification (ρ = 0.785, P < 0.05). CONCLUSIONS: This study provides novel evidence indicating that trunk strength and balance differ among various classes of WCB players, and objective measures of trunk function correlate positively with the current observation-based WCB classification system.

Quantitative evaluation of trunk muscle strength in wheelchair basketball players

Trunk muscle strength affects trunk controlling playing an important role in performance and to define the classes of wheelchair basketball players. Trunk control capacity differs among players and quantitative assessments of trunk muscle strength have not been investigated. The aim of this study was to identify and correlate quantitative measures of trunk muscle strength with the wheelchair basketball players' classification. Forty-two male wheelchair basketball players with spinal cord injury, amputation, post-poliomyelitis sequelae, and cerebral palsy had their trunk extension and flexion strength evaluated with isokinetic dynamometer. The classes 1.0, 2.0, 3.0, and 4.0 were considered for statistical analysis. Comparison of trunk muscle strength differed significantly between classes: 1.0 and 3.0; 1.0 and 4.0; 2.0 and 3.0; and 2.0 and 4.0. High correlation was found between the trunk muscle strength and players' classes. The findings of the present study showed a strong correlation of trunk muscle strength and wheelchair basketball classes being able to distinguish players in their classes. However, this quantitative method of evaluation of the trunk muscle strength cannot be solely used to make a decision on the full trunk control

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm2). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m²), waist-hip ratio and the support base (cm²). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults.

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm²). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m²), waist-hip ratio and the support base (cm²). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

Motivaçäo no esporte infanto-juvenil: uma discussäo sobre razöes de busca e abandono da prática esportiva entre crianças e adolescentes / Motivation in youth sports: a discussion about the reasons that children and teenagers look for and quit sports practice

O objetivo deste estudo foi determinar, através dos dados da literatura, quais fatores estariam influenciando a motivaçäo das crianças e adolescentes no que tange à prática esportiva. O principal questionamento colocado foi: por que diariamente milhares de crianças e adolescentes iniciam ou abandonam a prática esportiva? Observou-se que os fatores que determinam tais atitudes variam conforme a idade e o sexo. Geralmente,os principais motivos alegados por crianças e adolescentes para in iciar-se e persitir na prática esportiva foram: diversäo, bem-estar físico, competiçäo e novas amizades. Já os principais fatores alegados para oabandono da prática foram: falta de competiçäo, ênfase exagerada na vitória e excesso de pressöes por parte dos pais e dos técnicos. Seria de grande importância que pais, técnicos e dirigentes esportivos se sensibilizassem com tais questöes a fim de que cada vez mais crianças vivenciassem longos períodos de prática esportiva. (au)