Variability Analysis in Judo Para Athletes With Visual Impairments: Match-Outcome Performance in the Tokyo 2020 Paralympic Games With Evidence From the New Classification System.

Match-related performance analysis in judo Para athletes with visual impairments is important to coaches and staff to identify technical-tactical profiles of their athletes and opponents but also to identify whether there are similar characteristics in each visual class. Thus, this study explores the match-related performance in judo Para athletes and verifies the relationship between performance using the old and new classification systems. The match-derived variables were analyzed using different statistical methods considering a total of 182 matches from the Tokyo 2020 Paralympic Games. The results indicated that performance was affected by sex and degree of impairment. The new classification system seems suitable for grouping Para judo athletes, as it differentiates performance between the two proposed classes (J1 and J2), since athletes from each group compete separately. Furthermore, different variability index measures were correlated with competitive performance, demonstrating a specific performance profile for each sport class in judo.

How wide should you view to fight? Establishing the size of the visual field necessary for grip fighting in judo.

Peripheral vision is often considered vital in (combat) sports, yet most experimental paradigms (e.g., eye tracking) ignore peripheral information or struggle to make inferences about the role of peripheral vision in an in-situ performance environment. This study aimed to determine where visual information is located in the peripheral field during an in-situ combat sports task. Eight advanced judokas competed in grip-fighting exchanges while wearing a mobile eye-tracker to locate gaze direction. Three-dimensional position data of the head and hands were tracked using a VICON motion capture system. Gaze analysis through automatic feature detection showed that participants predominantly fixated on their opponent's chest. Kinematic data were used to calculate the angles between the opponent's hands and the gaze-anchor point on the chest of the opponent. Results revealed a nonlinear relationship between visual field (VF) size and visibility of the hands, with athletes needing a VF of at least 30-40 degrees radius to simultaneously monitor both hands of the opponent most of the time. These findings hold implications for the regulation of Paralympic judo for athletes with vision impairment, suggesting that a less severe degree of impairment should be required to qualify than the current criterion of 20 degrees radius.

Modelling the age-related trajectory of performance in Para swimmers with physical, vision and intellectual impairment.

This study is the first to provide information on the age-related trajectories of performance in Para swimmers with physical, vision and intellectual impairment. Race times from long-course swim meets between 2009 and 2019 were obtained for Para swimmers with an eligible impairment. A subset of 10 661 times from 411 Para swimmers were included in linear mixed effects modelling to establish the relationship between age and performance expressed relative to personal best time and world record time. The main findings were: (a) age has the most noticeable influence on performance between the ages of 12-20 years before performances stabilize and peak in the early to late twenties, (b) women have faster times relative to personal best and world record time than men during early adolescence and their performances stabilize, peak and decline at younger ages, and (c) Para swimmers from different sport classes show varying age-related trajectories in performance after maturation and when training-related factors are more likely to explain competitive swim performance. The results of this study can guide talent identification and development of Para swimmers at various stages of their career and help to inform decision-making on the allocation of sport class and sport class status in Para swimming classification.

Conceptual model of sport-specific classification for para-athletes with intellectual impairment.

The present paper describes the conceptual basis of evidence-based classification of para-athletes with intellectual impairment (II). An extensive description of the theoretical and conceptual foundation of the system as currently conceived is provided, as are examples of its applications in the three sports included in the Paralympic programme for II-athletes in 2020 (i.e., athletics, swimming and table tennis). Evidence-based classification for II-athletes is driven by two central questions: i. How can intellectual impairment be substantiated in a valid and reliable way, and ii. Does intellectual impairment limit optimal sport proficiency? Evolution of the system and current best practice for addressing these questions are described, and suggestions for future research and development are provided. Challenges of understanding and assessing a complex (multifaceted and intersectional) impairment in the context of sport also are considered.

Challenges and opportunities in wheelchair basketball classification- A Delphi study.

The International Paralympic Committee (IPC) mandates Paralympic Sports to develop evidence-based classification systems that allocate athletes into 'classes' according to the impact of their impairment on sport-specific performance. In wheelchair-basketball, a panel of classifiers assesses athlete's performance through observation. One key barrier to evidence-based classification is the absence of defined eligible impairments, including clear guidelines on how to assess them and their impact on wheelchair basketball performance. This study aims to reach expert consensus on issues specific to wheelchair basketball that can benefit from evidence-based classification. It offers recommendations for refining the classification manual, thus improving adherence to the IPC classification code. A three-round Delphi study was conducted with 29 experts in wheelchair basketball. The experts agreed with the new definition for the aim of wheelchair basketball classification, which is in line with the IPC code. Cases identified as having the highest risk for disagreement between classifiers included classifying players with upper limb deficiency or with impaired coordination. The panel failed to agree on changing the classification procedures and on defining the eligible impairment list. This study identifies issues specific to wheelchair basketball classification to be addressed in future research. Additional discussions need to take place to promote further resolution.

May the best-sighted win? The relationship between visual function and performance in Para judo.

This study aimed to establish the optimal cut-off point(s) between classes in a new, evidence-based classification system for VI judo. We collected results from international VI judo competitions held between 2012 and 2018. Data on visual acuity (VA) and visual field (VF) measured during classification were obtained. Performance was determined by calculating a win ratio for each athlete. VA was significantly associated with judo performance (r = -.33, p <.001), VF was not (r =.30, p =.15). Decision tree analysis suggested to split the data into two groups with a VA cut-off of 2.5 logMAR units. Stability assessment using bootstrap sampling suggested a split into two groups, but showed considerable variability in the cut-off point between 2.0 and 3.5 logMAR. We conclude that to minimise the impact of impairment on the outcome of competition, VI judo should be split into two sport classes to separate partially sighted from functionally blind athletes. To establish an exact cut-off point and to decide if other measures of visual function need to be included, we argue for continued research efforts together with careful evaluation of research results from a multidisciplinary perspective.

The impact of limb deficiency impairment on Para swimming performance.

Swimmers with limb deficiency are a core population within Para Swimming, accordingly this study examined the contribution of limb segments to race performance in these swimmers. Data were obtained for 174 male Para swimmers with limb deficiency. Ensemble partial least squares regression showed accurate predictions when using relative limb segment lengths to estimate Para swimmers' personal best race performances. The contribution of limb segments to performance in swim events was estimated using these regression models. The analysis found swim stroke and event distance to influence the contributions of limb segments to performance. For freestyle swim events, these changes were primarily due to the increased importance of the hand, and decreased importance of the foot and shank, as the distance of the event increased. When comparing swim strokes, higher importance of the thigh and shank in the 100 m breaststroke compared with other swim strokes confirms the separate SB class. Varied contributions of the hand, upper arm and foot suggest that freestyle could also be separated from backstroke and butterfly events to promote fairer classification. This study shows that swim stroke and event distance influence the activity limitation of Para swimmers with limb deficiency suggesting classification should account for these factors.

Wearable Wheelchair Mobility Performance Measurement in Basketball, Rugby, and Tennis: Lessons for Classification and Training.

Athlete impairment level is an important factor in wheelchair mobility performance (WMP) in sports. Classification systems, aimed to compensate impairment level effects on performance, vary between sports. Improved understanding of resemblances and differences in WMP between sports could aid in optimizing the classification methodology. Furthermore, increased performance insight could be applied in training and wheelchair optimization. The wearable sensor-based wheelchair mobility performance monitor (WMPM) was used to measure WMP of wheelchair basketball, rugby and tennis athletes of (inter-)national level during match-play. As hypothesized, wheelchair basketball athletes show the highest average WMP levels and wheelchair rugby the lowest, whereas wheelchair tennis athletes range in between for most outcomes. Based on WMP profiles, wheelchair basketball requires the highest performance intensity, whereas in wheelchair tennis, maneuverability is the key performance factor. In wheelchair rugby, WMP levels show the highest variation comparable to the high variation in athletes' impairment levels. These insights could be used to direct classification and training guidelines, with more emphasis on intensity for wheelchair basketball, focus on maneuverability for wheelchair tennis and impairment-level based training programs for wheelchair rugby. Wearable technology use seems a prerequisite for further development of wheelchair sports, on the sports level (classification) and on individual level (training and wheelchair configuration).

Adaptive Shooting Disciplines: A Scoping Review of the Literature with Bibliometric Analysis.

Para-archery and para-shooting, two very popular adaptive shooting disciplines that have earned their place as major official events in the Paralympic Games, share some similarities, as well as distinctive features in terms of rules, physiological requirements, and equipment used. The International Paralympic Committee has a clear responsibility to ensure that all sports within its jurisdiction, including adaptive shooting, can achieve excellence in their respective fields. To achieve this, the conduct of well-designed studies and rigorous research is essential. Although some research has been conducted in this area, a comprehensive and systematic evaluation is still needed. Therefore, the present study aims to provide a thorough review and synthesis of existing research on adaptive shooting disciplines, identify strengths and gaps, and suggest future directions. Arksey and O'Malley's methodology is leveraged and enhanced with bibliometric and policy analyses to review literature on adaptive shooting. Databases like PubMed/MEDLINE, Scopus, Web of Science, OvidSP, and EMBASE were searched, focusing on studies in adaptive shooting disciplines and analysing these findings through a blend of thematic and statistical methods. Twenty-four studies totalling 483 para-athletes (299 para-shooters and 184 para-archers) are included in this scoping review, focusing on a range of aspects, including physiological responses (n = 9), research design and measurement methods for evidence-based classification (n = 6), biopsychosocial aspects (n = 3), development of new methods and technologies (n = 4), kinematic and biomechanical assessment (n = 1), and epidemiology of injuries (n = 1). Seven articles focused exclusively on para-archery, thirteen exclusively on para-shooting, and four on both para-archery and para-shooting. In conclusion, the available literature on adaptive shooting disciplines is still very limited, especially regarding para-archery compared to para-shooting. This highlights the need for further research in many key areas to ensure a better understanding of the different disciplines and to provide appropriate support for para-athletes. Future research in para-archery and para-shooting should focus on technological innovations, biomechanical studies, and psychological support to enhance athlete performance and accessibility. Addressing the imbalance between the two disciplines, along with injury prevention and global participation, can drive the sports towards greater inclusivity and equity for para-athletes worldwide.

Adding Evidence to an Evidence-Based Classification for Recurrent Weight Gain after Bariatric and Metabolic Surgery from a Norwegian National Registry.

BACKGROUND: In 2023, the first evidence-based classification for recurrent weight gain (RWG) after metabolic and bariatric surgery was introduced. It uses early and late follow-up weight loss benchmarks based on standard deviations (SD) of percentage total weight loss(%TWL) results from the large Dutch Audit for Treatment of Obesity (DATO) registry (n > 18,000). We aimed to validate this classification and confirm its clinical relevance with an external cohort. METHODS: The DATO-based classification defines all RWG as grade 1, as long as weight-loss does not drop below DATO's late-follow-up minus one SD benchmark (20%TWL). Grade 3 represents clear outliers whose RWG evolves below DATO's late follow-up minus two SD benchmark (10%TWL), with grade 2 in-between. Grades 2a/3a represent initial suboptimal clinical response, with nadir %TWL never exceeding DATO's early-follow-up minus one SD benchmark (25%TWL). Grades 2b/3b represent late clinical deterioration from nadir weight loss ≥ 25%TWL. We compared baseline characteristics, SD based benchmarks, RWG and comorbidities from the Scandinavian Obesity Surgery Registry Norway (SOReg-N) with these DATO-derived grades. RESULTS: The SOReg-N population (n = 3064) was comparable at baseline, with more sleeve gastrectomies (54% versus DATO 22.5%). The SD benchmarks were at early follow-up minus one SD 25.8%TWL, at 5 years minus one SD/minus two-SD 17.2%TWL/7.0%TWL (DATO 25%TWL/20%TWL/10%TWL). Percentage of patients and amount of RWG were similar to DATO. In line with DATO, comorbidities were predominant in grades 2a/3a, with least improvement in grade 3a. Also, grade 3b showed more favorable characteristics at baseline. CONCLUSION: The SOReg-N cohort confirmed the weight-loss benchmarks defining the DATO-derived grades, the distribution of patients and their RWG across the grades, and correlations between grades and comorbidities. Male gender, older age and comorbidities were predominant among patients with initial suboptimal clinical response (RWG grades 2a/3a), but not for late clinical deterioration (RWG grades 2b/3b). This classification can be used for populations with diverse weight loss trajectories and offers an evidence-based guide for clinical decision-making and standardization.

Anaerobic Variables As Specific Determinants of Functional Classification in Wheelchair Basketball.

Every parasport is currently encouraged to consider evidence-based classification to develop their respective classification system. Therefore, the aims of this study were to: (1) assess the relationship between trunk function and anaerobic power determining proficiency in wheelchair basketball, and (2) define "natural classes" in wheelchair basketball based on anaerobic power. Fifty-nine elite players (representing five national teams) were divided into four main functional classes: Group 1 (n=17), Group 2 (n=14), Group 3 (n=16), Group 4 (n=12). They performed the 6x10s Anaerobic Power Test using an arm crank ergometer. Average values of mean power, peak power, relative mean power, relative peak power, and power decrement were calculated for the 6x10s and 3x10s tests. The Spearman's correlation matrix revealed significant correlations between classes and values recorded in the 6x10s test. This confirmation between anaerobic power and players' classification endorses the division of players into different classes. Furthermore, cluster analysis (with fair quality) divided players into two "natural classes". The first resulting class was mainly formed of participants from Group 1 (71%). An important complement to this research could be to consider wheelchair acceleration and the volume of trunk action in wheelchair basketball classification.

The Relationship Between Visual Function and Performance in Para Swimming.

BACKGROUND: Paralympic swimmers with vision impairment (VI) currently compete in one of the three classes depending on their visual acuity (VA) and/or visual field. However, there is no evidence to suggest that a three-class system is the most legitimate approach for classification in swimming, or that the tests of VA and visual field are the most suitable. An evidence-based approach is required to establish the relationship between visual function and performance in the sport. Therefore, the aim of this study was to establish the relationship between visual function and performance in VI Para swimming. The swimming performance of 45 elite VI swimmers was evaluated during international competitions by measuring the total race time, start time, clean swim velocity, ability to swim in a straight line, turn time, and finish time. Visual function was measured using a test battery that included VA, contrast sensitivity, light sensitivity, depth perception, visual search, and motion perception. RESULTS: Results revealed that VA was the best predictor of total race time (r = 0.40, p < 0.01), though the relationship was not linear. Decision tree analysis suggested that only two classes were necessary for legitimate competition in VI swimming, with a single cut-off between 2.6 and 3.5 logMAR. No further significant association remained between visual function and performance in either of the two resulting classes (all |rs|< 0.11 and ps > 0.54). CONCLUSIONS: Results suggest that legitimate competition in VI swimming requires one class for partially sighted and another for functionally blind athletes.

Validity and reliability of isometric tests for the evidence-based assessment of arm strength impairment in wheelchair rugby classification.

OBJECTIVES: The purpose of this study was to examine the validity and test-retest reliability of a battery of single-joint isometric strength tests, to establish whether the tests could be used for evidence-based classification in wheelchair rugby (WR). DESIGN: Cross-sectional. METHODS: Twenty male WR athletes with impaired arm strength and thirty able-bodied (AB) participants (15 male, 15 female) performed four isometric strength tests. Each test required three 5-s efforts and examined maximal isometric force for flexion and extension around the shoulder and elbow joint. Test validity was established by comparing differences (Cohen's effect sizes [d]) in strength between WR athletes and AB participants. Differences were also explored between male and female AB participants. Twenty AB participants returned for a second visit to establish the test-retest reliability of the test battery. RESULTS: Significantly lower force values were observed for all isometric strength measures in WR athletes compared to AB participants (p≤0.0005; d≥2.14). Female AB participants also produced significantly less force than male AB participants for all joint actions (p≤0.0005; d≥1.93). No significant differences were identified between trials for any measure of strength, with acceptable levels of test-retest reliability reported (ICCs≥0.97, SEM≤19.3N and CV≤8.4%). CONCLUSIONS: The current results demonstrated the validity of a battery of isometric strength tests, suggesting they can be used to reliably infer strength impairment in WR athletes, which is a pre-requisite when working towards evidence-based classification in Paralympic sport.

Maximal Fully Tethered Swim Performance in Para Swimmers With Physical Impairment.

The assessment of swimming propulsion should be a cornerstone of Paralympic swimming classification. However, current methods do not objectively account for this component. PURPOSE: To evaluate the swimming propulsion of swimmers with and without physical impairment using a 30-second maximal fully tethered freestyle swim test. METHODS: Tethered forces were recorded during maximal fully tethered swimming in 80 competitive swimmers with (n = 70) and without (n = 10) physical impairment. The relationships between absolute and normalized tether forces and maximal freestyle swim speed were established using general additive models. RESULTS: Para swimmers with physical impairment had lower absolute and normalized tether forces than able-bodied swimmers, and there were moderate positive correlations found between tether forces and sport class (τ = .52-.55, P < .001). There was a nonlinear relationship between tether force and maximal freestyle swim speed in the participant cohort (adjusted R2 = .78-.80, P < .001). Para swimmers with limb deficiency showed stronger relationships between tether force and maximal freestyle swim speed (adjusted R2 = .78-.82, P < .001) than did Para swimmers with hypertonia (adjusted R2 = .54-.73, P < .001) and impaired muscle power (adjusted R2 = .61-.70, P < .001). CONCLUSIONS: Physical impairments affect Para swimmers' tether forces during maximal fully tethered freestyle swimming, explaining a significant proportion of their activity limitation. It is recommended that maximal fully tethered swimming be included in Paralympic swimming classification as an objective assessment of swimming propulsion.

Using Fitts' Law to Detect Intentional Misrepresentation.

In paralympic classification, tests of impaired coordination (e.g., reciprocal tapping tasks) are effort dependent and therefore susceptible to intentional misrepresentation of abilities (IM)-deliberate exaggeration of impairment severity. The authors investigated whether reciprocal tapping tasks performed submaximally could be differentiated from tapping tasks performed with maximal voluntary effort, based on conformity with Fitts' law. Ten nondisabled participants performed 14 tapping tasks with their dominant hand on 3 separate occasions. Seven tasks were performed with MVE and the other 7 at speeds that were at least 20% slower. Results revealed that evaluating conformity with Fitts' law is a potentially valid method for objectively detecting IM during reciprocal tapping. Evaluation of sensitivity and specificity of the method is now warranted.