Biomechanics of starting, sprinting and submaximal running in athletes with brain impairment: A systematic review

Physical performance and technical specific skills of women football players with cerebral palsy

This study aimed to determine the physical performance profile (ability to change direction, vertical and horizontal jump, sprint ability, and dribbling-specific skills) of the first women football players with cerebral palsy (CP) who participated in an international CP football competition, accounting for their sport classes. We also examined the relationships between the different physical performance variables. Forty-five female players with CP (24.9 ± 7.5 years) were categorised into three sport classes based on their impairment severity: 19 were FT1 (severe impairments); 21 FT2; and 5 FT3 (mild impairments). Various physical performance tests were conducted, including the 505 change of direction test; vertical and horizontal jumps; 10 m sprint test; and the dribbling speed test. Significant correlations were observed between the change of direction ability, sprint (r = 0.89; p < 0.01), and dribbling tests (r = 0.71; p < 0.01), as well as between horizontal jump and sprint time (r =  - 0.74; p < 0.01). FT1 players demonstrated poorer performance compared to FT3 in the 505 test and standing broad jump (p < 0.05; dg = -1.79 and 1.22 respectively), but also lower vertical jump heights (p < 0.05; dg = -0.91 to -1.57) and increased time required for sprint (p < 0.05; dg = 0.88 to 1.16) and dribbling tests (p < 0.05; dg = 0.85 to 1.44) compared to both FT2 and FT3 players. These findings offer valuable insights into the physical performance characteristics of female footballers with CP, which can guide training and sport enhancement programs for this unique para-sport population.

Sex differences in change of direction deficit and asymmetries in footballers with cerebral palsy

The aims of this study were (1) to describe and examine differences in change of direction (COD) performance and the magnitude of asymmetries in para-footballers with cerebral palsy (CP) and controls and (2) to evaluate the association between COD outcomes and linear sprint performance. Twenty-eight international para-footballers with CP and thirty-nine non-impaired football players (control group) participated in this study. All participants completed a 10-m sprint and two attempts of the 505 COD test with the dominant and non-dominant leg. The COD deficit was calculated using the difference between the 505 test and the 10-m sprint time, while the asymmetry index was determined by comparing each leg's completion time and COD deficit. Players across groups showed interlimb asymmetries between the dominant and non-dominant legs in COD outcomes and deficit (p < 0.05, d_g  = -0.40 to -1.46), although these asymmetries imbalance were not significantly different between the sexes with and without impairment. Males with CP exhibited a faster directional COD speed and a shorter COD deficit than their female counterparts (p < 0.01, d_g  = -1.68 to -2.53). Similarly, the control group had faster scores than the CP groups of the same sex (p < 0.05, d_g  = 0.53 to 3.78). Lastly, the female CP group and male control groups showed a significant association between sprint and the COD deficit in the dominant leg (p < 0.05, r = -0.58 to 0.65). Therefore, the use of directional dominance, the COD deficit, and asymmetry outcomes could be helpful for classification purposes to assess the impact of the impairment on sport-specific activity testing according to sex.

Sex-specific differences in biomechanics among runners: A systematic review with meta-analysis

Patellofemoral disorders are more common in female runners compared to their male counterparts. Differences in biomechanical characteristics between groups of runners could provide insight into the causes of higher rates of injury in female versus male runners, which would be useful to physical therapists and athletic trainers in development of individualized injury prevention programs. This review compares the differences in biomechanical characteristics between female and male runners. Electronic databases, including PubMed, Scopus, Web of Science, and Embase were searched in December 2021 for studies evaluating sex-specific differences in lower limb mechanics of healthy participants during running. Two independent reviewers determined the inclusion and quality of each research paper. Meta-analyses were used where possible. A total of 13 studies were selected. Means and standard deviations of reported data were retrieved from each selected paper for comparison of results. Three biomechanical variables, including dynamics, muscle activation, and kinematics, were compared between female and male runners. However, no differences were found in kinetic variables or muscle activation between groups due to insufficient data available from the selected studies. Meta-analyses of kinematic variables revealed that female runners exhibited significantly greater hip flexion angle, hip adduction angle, and hip internal rotation angle, but smaller knee flexion angle compared to male runners during running. We found significant differences in kinematic variables between female and male runners, which could influence the training advice of physical therapists and athletic trainers who work with runners, and inform the development of injury prevention programs.

THE REACTION SPEED OF SPORTS ATHLETES IN DIFFERENT STATE LEVELS

ABSTRACT Introduction: The start of a sprint race is one of its most important stages. The reaction time at the start lays a psychological foundation for normal performance and performance improvement in its next three stages. Objective: To research the reaction time of athletes in the starting stage of the 100-meters sprint race. This helps analyze the internal reaction mechanism of the body, which receives signals and responds to actions. Methods: We use a bibliographical research, experimental comparison, and mathematical statistics to study the starting reaction time of sprinters. Results: The starting reaction time of male and female sprinters was basically at the same level. Conclusion: The starting time of Chinese sprinters needs to be improved. 400-m sprinters, especially, should devote more training to their starting reaction time. Level of evidence II; Therapeutic studies - investigation of treatment results.

To What Degree Does Limb Spasticity Affect Motor Performance in Para-Footballers With Cerebral Palsy?

Spasticity is considered a contributor to hypertonia, frequently presented in people with cerebral palsy (CP), affecting muscle function and motor activities. In CP football, the classification system determines that this impairment is eligible for competitive para-sports due to the impact on activity limitation and sports performance. However, the relationship between this feature (i.e., spastic hypertonia) and performance determinants has not been explored yet. This study aimed to assess the association of clinical spasticity measurements with the performance of sport-specific tests used for classification purposes. Sixty-nine international footballers with CP voluntarily participated in this study. The Australian Spasticity Assessment Scale was used to measure spasticity in lower limbs muscle groups and activity limitation tests were conducted considering dynamic balance, coordination, vertical and horizontal jumps, acceleration, and change of direction ability. Low-to-moderate negative significant associations were found between the hip spasticity and measures of dynamic balance and dominant unipedal horizontal jump capacity. Additionally, moderate associations were reported between the knee spasticity and the non-dominant unipedal horizontal jump capacity and the change of direction actions with the ball. The ankle spasticity score reported small to moderate associations with the change of direction assessment without the ball and bipedal and dominant unipedal horizontal jump capability. Finally, the total spasticity score only presented a significant association with horizontal jump performance. This is a novel study that provides evidence of the associations between an eligible neural impairment and relevant specific measures of activity limitation tests. These results suggest that the amount of spasticity according to each evaluated joint muscle group of the lower limbs presents a low-to-moderate significant relationship with determined measures of dynamic balance, coordination, horizontal jump, acceleration, and change of direction ability with and without the ball in international-level CP footballers. Further studies are necessary to elucidate the real contribution of neural and non-neural impairments related to hypertonia on fundamental sport-specific motor skills of para-footballers with CP.

Lower Limb Kinematic Coordination during the Running Motion of Stroke Patient: A Single Case Study

The purpose of this study was to clarify the lower limb joint motor coordination of para-athletes during running motion from frequency characteristics and to propose this as a method for evaluating their performance. The subject used was a 43-year-old male para-athlete who had suffered a left cerebral infarction. Using a three-dimensional motion analysis system, the angles of the hip, knee, and ankle joints were measured during 1 min of running at a speed of 8 km/h on a treadmill. Nine inter- and intra-limb joint angle pairs were analyzed by coherence and phase analyses. The main characteristic of the stroke patient was that there were joint pairs with absent or increased coherence peaks in the high-frequency band above 4 Hz that were not found in healthy subjects. Interestingly, these features were also observed on the non-paralyzed side. Furthermore, a phase analysis showed different phase differences between the joint motions of the stroke patient and healthy subjects in some joint pairs. Thus, we concluded there was a widespread functional impairment of joint motion in the stroke patient that has not been revealed by conventional methods. The coherence analysis of joint motion may be useful for identifying joint motion problems in para-athletes.