Kinematic and Kinetic Analyses of the Vertical Jump with and without Header as Performed by Para-Footballers with Cerebral Palsy

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.

Differences in kinetic characteristics during countermovement jump of football players with cerebral palsy according to impairment profiles

Objectives: The purpose of this study was 1) to determine and compare kinetic parameters during the realization of a countermovement jump (CMJ) between footballers with cerebral palsy (CP) and non-impaired footballers, and 2) to analyze the differences in this action between different players' impairment profiles and a group of non-impaired footballers. Methods: This study involved 154 participants comprising 121 male footballers with CP from 11 national teams and 33 male non-impaired football players recruited as the control group (CG). The footballers with CP were described according to the different impairment profiles (bilateral spasticity = 10; athetosis or ataxia = 16; unilateral spasticity = 77; minimum impairment = 18). All participants performed three CMJs on a force platform to record kinetic parameters during the test. Results: The group of para-footballers presented significantly lower values than the CG in the jump height (p < 0.01, d = -1.28), peak power (p < 0.01, d = -0.84), and the net concentric impulse (p < 0.01, d = -0.86). Concerning the pairwise comparisons between CP profiles and the CG, significant differences were found for the bilateral spasticity, athetosis or ataxia, and unilateral spasticity subgroups compared to the non-impaired players for jump height (p < 0.01; d = -1.31 to -2.61), power output (p < 0.05; d = -0.77 to -1.66), and concentric impulse of the CMJ (p < 0.01; d = -0.86 to -1.97). When comparing the minimum impairment subgroup with the CG, only significant differences were found for jump height (p = 0.036; d = -0.82). Footballers with minimum impairment presented higher jumping height (p = 0.002; d = -1.32) and concentric impulse (p = 0.029; d = -1.08) compared to those with bilateral spasticity. Also, the unilateral spasticity subgroup reports a higher jump height performance than the bilateral group (p = 0.012; d = -1.12). Conclusion: These results suggest that the variables related to power production during the concentric phase of the jump are crucial for the performance differences between groups with and without impairment. This study provides a more comprehensive understanding of kinetic variables that would differentiate CP and non-impaired footballers. However, more studies are necessary to clarify which parameters better differentiate among different profiles of CP. The findings could help to prescribe effective physical training programs and support the classifier's decision-making for class allocation in this para-sport.

Analysis of scored goals in the cerebral palsy football World Cup

This study aimed to report the goal patterns in cerebral palsy (CP) football for a better understanding of the performance of this para-sport. All goals (270) of the 48 2019 IFCPF World Cup matches were analysed through match reports, and 65% of them were analysed by video footage. The results showed 5.6 goals per match. Teams that scored more and conceded fewer goals correlated to a better ranking position in the championship (r= 0.72-0.73; p< 0.01). The distribution of goals scored was not biased by halves (49.3% vs 50.7%; χ²= 0.1; p= 0.88) nor by 15-min periods (26.3% vs 23.0% vs 23.3% vs 27.4%; χ²= 0.5; p= 0.92). In 91.7% of the matches, the team which scored the first goal went on to win the match (χ²= 81.5; p< 0.01). FT3 players scored more goals by player (χ²= 22.1; p< 0.01), while there were no statistical differences in the distribution of goals conceded by goalkeepers according to their sport class (χ²= 4.7; p= 0.09). The goals were scored mainly from organized attacks (74.4%), from the penalty area (52.5%) and through individual action (51.9%). All this information could be crucial for coaches in CP football to plan their game strategies.

Changes in Sprint Force-Velocity Profile in International Para Footballers

PURPOSE

Force production is crucial in football, and it is the main limitation of people with cerebral palsy (CP). This study aimed to describe the changes in sprint force-velocity (Fv) profile after a period of 25 weeks of regular training in international football players with CP.

METHODS

The sprint Fv profile and other physical performance variables (ie, linear sprint, vertical jump, change of direction, and intermittent endurance) of 14 international players from the Spanish national team were assessed during 2 consecutive training camps. Pretesting and posttesting sessions were carried out 1 week before and after the 25-week intervention period. The intervention consisted of 2 strength sessions per week added to the usual football training.

RESULTS

The repeated-measures analysis of variance showed changes in players' physical performance (linear sprint: F = 18.05, P < .01; change of direction: F = 16.71, P < .01; and endurance: F = 31.45, P < .01) and in some variables of the sprint Fv profile (maximal horizontal force, maximal power, slope, maximal ratio of force, and decrease of ratio of force; F = 14.28-37.81; P < .01), whereas players' maximal velocity (theoretical and actual) did not change (F = 0.13 and 0.01; P = .72 and .98, respectively).

CONCLUSIONS

This study showed that the implementation of 2 strength-training sessions per week, for 25 weeks, is effective to improve CP football players' physical performance. The main finding of this study is the improvement of force application in the acceleration phase (sprint Fv profile), which is the main attribute in many physical performance tests and is the main limitation of the CP population.

Analysis of Injuries and Wellness in Blind Athletes during an International Football Competition

Five-a-side football for blind people is the only adapted football modality present at the Paralympic games. Fa5 is a collaborative-opposition sport in which its participants play with no vision, which causes numerous impacts. At the London 2012 Paralympic Games, it was the sport with the highest incidence of sports injuries. The main objective of this work is to analyse the association between pain perception; spatio-temporal, mechanical, and metabolic workload with injuries; and wellness in players during an international Fa5 competition. The following variables, monitored during an International Fa5 Tournament, were analysed: general well-being, perception of pain and injuries, and the spatio-temporal and metabolic workload. The results show that the incidence of injuries increases as the tournament progresses, where injured players reported greater muscle pain and stress before the matches started. Besides, the players’ internal and external load did not explain the incidence of injury. Still, the values obtained in the wellness questionnaire, the perception of pain, and stress suggested they contributed to the incidence of injury.

Physical Performance Differences Between Spanish Selected and Nonselected Para-Footballers With Cerebral Palsy for the National Team

In regular football, the players' selection process involves an objective assessment based on their anthropometric and physical performance. However, available literature focused on players' selection process in cerebral palsy (CP) football is scarce.

PURPOSE

To describe the anthropometrical and physical performance profiles of the International Spanish CP footballers and to compare them with the remaining CP football players from the national competition.

METHOD

A total of 75 CP football players from the Spanish CP Football National Competition (classified into the 3 existing classes: football class [FT] 1 = 38; FT2 = 29; FT3 = 8) participated in the study. Participants were divided into 2 groups: selected players (n = 15) and nonselected players (n = 60) for the national team. Anthropometrical data and physical performance (countermovement jump, 20-m sprint, modified agility T-test [MAT], and dribbling test) were collected.

RESULTS

There were significant differences in the 20-m sprint, MAT, and dribbling for the total sample and in MAT and dribbling for FT2 and FT3 classes between selected players and nonselected players (P < .05), but there were no differences for FT1. The MAT and dribbling showed a positive correlation and a high percentage of player selection prediction.

CONCLUSION

Change-of-direction ability (ie, MAT) and dribbling skills are important when performing the selection process, as they allow the evaluation of important aspects of the game, but they may also provide the technical staff with an idea of the functionality and the physical performance of the players in each sport class.

Using Decision Trees to Support Classifiers' Decision-Making about Activity Limitation of Cerebral Palsy Footballers

This study aimed (1) to determine the appropriateness of using decision trees as a classification tool for determining the allocation of sport classes of para-footballers with "moderate vs. mild" cerebral palsy (CP) profiles of spastic diplegia/hemiplegia and ataxia/athetosis based on observational outcomes by international classifiers, and (2) to identify what key observational features were relevant to discriminating among different impairment levels. A sample of 16 experienced international classifiers from five world regions participated in this study, observing activity limitation of a final sample of 21 international CP footballers when performing 16 gross-motor and sports-specific tests for balance (n = 3), coordination (n = 5), running, accelerations and decelerations (n = 3), jumping (n = 4), and change of direction ability (n = 1). For the overall sample (336 observations), the model included eight decision nodes and 24 branches with 17 leaves, including side-step, side-stepping, and triple hop as the tests with the best sensitivity (precision = 67.0%). For those with spastic diplegia (64 observations: Two nodes, six branches with five leaves), the range of motion in the side-step test and the balance in the tandem walk tests correctly classified 89.1% of the observations. In those with athetosis and ataxia (96 observations), the model included five nodes, 15 branches, and 11 leaves (176 observations, precision = 86.5%). For those with spastic hemiplegia, a model containing two nodes, six branches, and five leaves had 90.9% accuracy, including observational features of balance in the side-step test and symmetry in the side-stepping test. The observational tool used in this study, based on the impact of specific impairment measurements of hypertonia, athetosis, and ataxia, can be used to determine which assessments are more appropriate for discriminating between functional profiles in para-footballers with CP.

Is impaired coordination related to match physical load in footballers with cerebral palsy of different sport classes?

Impaired coordination is a characteristic feature in cerebral palsy (CP) football players. This study aimed to determine the relationships of three coordination tests with match physical load during competition of para-footballers from different sport classes. Records from 259 para-footballers from 25 national teams were obtained in four international competitions held in 2018 and 2019. The three coordination tests were conducted prior to competition (i.e., rapid heel-toe, side-stepping, and split jumps), and physical match load was recorded by GPS devices during the real game: i.e., maximum/mean, total distance, distance covered at different speed zones, number of accelerations/decelerations at different intensities, and player load. FT1 and FT3 players have the lowest and highest performance in all the coordination tests, respectively, but inconclusive between-groups differences were obtained (p=0.022‒0.238). Split jumps and side-stepping tests are associated with the performance of moderate and high accelerations during competition (r = -0.20‒0.71; p<0.01). Significant correlations (r = 0.36‒0.71; p<0.01) were obtained between all the coordination measures. Coordination tests better discriminate those with more severe impairments and some evidence for the validity of the new CP football sport classes is provided. Further research is necessary to identify the portion of the variance in sports performance that coordination explains.

Anthropometrical Features of Para-Footballers According to Their Cerebral Palsy Profiles and Compared to Controls

Cerebral palsy (CP) football is a team para-sport practiced by para-athletes with eligible impairments of hypertonia, athetosis, and ataxia. This study aimed: (1) to describe the anthropometrical and body composition profiles of international CP para-footballers with different CP profiles (i.e., spastic diplegia, athetosis/ataxia, spastic hemiplegia, and minimum impairment); (2) to analyze the differences between both affected/nondominant and nonaffected/dominant sides; and (3) to compare the sample of international-level CP para-footballers (n = 141) with a sample of highly trained able-bodied footballers (n = 39). Anthropometric measures included four breadths, nine girths, and six skinfolds, while body composition was measured through fat mass (including Carter's, Faulkner's, and Withers' equations), muscle mass (Lee's equation), and bone mass (Rocha's and Martin's equations). This study found differences between the able-bodied footballers and the following impairment profiles: spastic diplegia (skinfolds); ataxia/athetosis (corrected calf of the nondominant side, and calf skinfolds for both sides); and spastic hemiplegia (all measurements excepting femur breadth, and thigh and ankle girths). No differences were found between para-athletes with minimum impairment and the able-bodied footballers. This study demonstrates that football players with or without physical impairments of hypertonia athetosis or ataxia may be considered homogeneous in shape when dominant size is compared. Besides, the study provides reference scores on anthropometric measures and body composition of international-level CP para-footballers that can help sports coaches and physical trainers to monitor physical fitness of their para-athletes.

Modified desk height helps children with cerebral palsy perform sit-to-stand

Aim: Children with cerebral palsy (CP) have difficulties performing activities that require the use of fundamental motor skills such as sit-to-stand (STS). In this study, we used a height adjustable chair and desk to investigate the role of desk support in STS and how it might benefit children with CP. Methods: Seventeen typically developing children (TDC), average age = 9.7 years, and 28 children with CP (Gross Motor Function Classification System [GMFCS] I and II), average age = 10.3 years, participated in the test. Elapsed time and body sway were measured using a pressure mat and load cell while each child performed a STS task. Two different desk heights were tested for time consumption and sway under the condition of hands-on-desk and arms-crossed. Results: We found that the elapsed time of hands-on-desk with the elbow flexion height was the shortest (p < 0.05). Sway amount was also significantly reduced for all children when they used the table for STS (p < 0.05). Conclusion: Results of this study may be a useful reference in rehabilitation training and designing a desk height beneficial for children with CP.Implications for RehabilitationBetter performance of sit-to-stand for a child with cerebral palsy could be made by a desk supportElapsed time during preparation period for sit-to-stand could be reduced by desk support for all CP childrenSway amount during sit-to-stand could be reduced by desk support, especially for the CP children with GMFCS level IIDesk height is an important parameter and should be studied in detail.

An Observational Tool to Assess Activity Limitation in Ambulatory People with Cerebral Palsy When Performing Motor Skills

Ratios of physical activity and sports participation in people with cerebral palsy (CP) are still low compared with people without a disability. For an adequate and useful practice, physical activity professionals should understand how different types of CP profiles constrain the performance of motor skills that are required during sports practice. This study aims to develop an observation-based assessment tool to evaluate activity limitations in individuals with a moderate level of CP when performing skills requiring jumping, sprinting, change of direction, coordination, and balance. Nineteen observers with different backgrounds from five world regions were recruited for this study, with accredited experience classifying/observing para-athletes with CP. All observers watched videos of 20 international para-athletes with different CP profiles (bilateral spasticity, athetosis/ataxia, unilateral spasticity; all Gross Motor Function Classification System level I) performing 16 motor tasks, and their observations were recorded throughout an ad-hoc data collection instrument. A total of 6080 units of qualitative information were recorded for data analysis. An observation-based tool with qualitative descriptors is derived from data analyses, describing how coordination and balance affected mainly in those with dyskinesia/ataxia, range of movement in those with diplegia, and asymmetries in those with hemiplegia. This tool would help sports practitioners and physical educators to better understand how different CP profiles constrain the performance of motor skills.

Validity and Reliability of a Test Battery to Assess Change of Directions with Ball Dribbling in Para-footballers with Cerebral Palsy

The purpose of this study was to evaluate the content and construct validity and between-sessions reliability of four agility tests requiring ball dribbling in football players with cerebral palsy (CP) with implications for classification and training. A sample of 35 football players with CP from three different countries took part in the study. They performed four tests in two sessions 72 h apart: i) 20 m in a straight line, ii) forward slalom with short changes of direction, iii) forward slalom with wide changes of direction and iv) square course. The Kappa coefficient was used to test content validity, obtaining moderate to almost perfect agreement results. Construct validity was also demonstrated with very large to almost perfect correlations between tests and sessions. Good reliability was found using intra-class coefficients (>0.86), standard error of measurement (<10.8%) and Cronbach´s alpha (>0.86). The comparisons between CP profiles (i.e. sport classes) demonstrated that those with mild impairment performed faster, and those with impairment of ataxia and dyskinesia performed worse. The four tests could have applications in classification, but may also be applied by the CP football coaches to improve athlete agility and football skills.