Emma Beckman

Paralympic classification: conceptual basis, current methods, and research update.

Paralympic classification systems aim to promote participation in sport by people with disabilities by controlling for the impact of impairment on the outcome of competition. Valid systems of classification ensure that successful athletes are those who have the most advantageous combination of anthropometric, physiological, and/or psychological attributes, and who have enhanced them to the best effect. Classification systems that are not valid pose a significant threat to Paralympic sport and, therefore, the International Paralympic Committee (IPC) has a Classification Code which includes policy commitment to the development of evidence‐based methods of classification. The aim of this article is to provide an overview of current best practice in classification for athletes with physical impairments, and to update research advances in the area. Currently, classification has 4 stages: (1) establish whether the athlete has a health condition that will lead to one or more of the 8 eligible types of physical impairment, (2) determine whether the athlete has an eligible impairment type, (3) determine whether the impairment is severe enough, and (4) determine in what class the athlete should compete. A sequential 4‐step process that outlines how to initiate and develop evidence‐based methods of classification is described: (1) specification of impairment types that are eligible for the sport; (2) development of valid measures of impairment(s); (3) development of standardized, sport‐specific measures of performance; and (4) assessment of the relative strength of association between measures of impairment and measures of performance. Of these, the development and reporting of valid measures of impairment is currently the most pressing scientific challenge in the development of evidence‐based methods of classification.

Towards evidence-based classification in Paralympic athletics: evaluating the validity of activity limitation tests for use in classification of Paralympic running events

Objective: To classify Paralympic athletes, classifiers use test batteries to obtain an objective, pre-competition estimate of an athlete’s training level. Five tests were evaluated to determine which combination explained the maximum variance in running performance in a non-disabled population. A non-disabled sample was required to permit psychometric evaluation of the tests without the confounding influence of impairment, and to provide an indication of normative performance. Design: Sixty-seven non-disabled participants (male and female; mean (SD) age 24.78 (6.53) years) completed a six-test battery comprising a 30 m sprint (criterion activity limitation test) and five supplementary activity limitation tests: standing broad jump, four bounds, 10 m skip, running in place and split jumps. Results: Test reliability was high for all tests (intraclass correlations  =  0.80–0.99). Pearson correlations with the 30 m sprint were moderate to strong for standing broad jump (−0.82), four bounds (−0.80) and 10 m skip (0.67), but weaker for split jumps (0.35) and running in place (0.19). Multiple regression indicated that standing broad jump, four bounds and 10 m skip explained 75% of the variance in running performance. Conclusions: The test battery is reliable and valid in the non-disabled population and therefore has potential utility in Paralympic classification. Test results were normally distributed, a necessary prerequisite for meaningful interpretation of future studies in athletes with impairments. Further studies evaluating the battery in populations of athletes with impairments of coordination, strength and range of movement are now warranted.

Trunk strength effect on track wheelchair start: implications for classification.

PURPOSE The T54 wheelchair racing class comprises athletes with normal arm muscle strength and trunk strength ranging from partial to normal. Paralympic sports classes should comprise athletes who have impairments that cause a comparable degree of activity limitation. On the basis of this criterion, the purpose of this study was to determine whether the T54 class is valid by assessing the strength of association between trunk strength and wheelchair acceleration. METHODS Participants were 10 male and 3 female international wheelchair track athletes with normal arm strength. Six were clinically assessed as having normal trunk strength, and seven had impaired trunk strength. Measures included isometric arm and trunk strength and distance covered at 1, 2, and 3 s in an explosive start from standstill on a regulation track, as well as on a custom-built ergometer with four times normal rolling resistance. RESULTS No significant differences were observed between male athletes with and without full trunk strength in distance covered after 1, 2, and 3 s. Correlations between isometric trunk strength and wheelchair track acceleration were nonsignificant and low (0.27-0.32), accounting for only 7%-10% of variance in performance. Correlations between trunk strength and distance pushed under high resistance were also nonsignificant, although values were almost double (r = 0.41-0.54), accounting for 18%-28% of the variance in performance. CONCLUSIONS These results provide evidence that impairment of trunk strength has minimal effect on wheelchair acceleration and indicate the T54 class is valid. Results do not infer that athletes with no trunk strength should compete with those who have partial or full trunk strength.

Injury risk management plan for volleyball athletes.

Volleyball is an increasingly popular team sport. As with any competitive sport, there is an inherent risk of injury that must be recognized and collaboratively managed. This article provides a practical approach to the management of volleyball injuries within a team or organization. A brief review of the epidemiological data is presented which establishes (i) ankle sprain, (ii) shoulder overuse injury, (iii) patella tendinopathy, and (iv) anterior cruciate ligament injury as the primary injuries to address amongst these athletes. The interaction of modifiable and non-modifiable risk factors for these injuries are used to classify athletes into high-, medium- and low-risk groups. Targeted training interventions are suggested, based upon the risk level of the athlete, to minimize the occurrence of these injuries. Practical methods for integrating these activities into a training plan are also discussed.

How much does lower body strength impact Paralympic running performance

Abstract Objectives: Development of evidence-based methods of Paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and athletic performance. The purpose of this study was to quantify the extent to which muscle strength affects running performance in runners with and without brain impairment. Design: Cross-sectional study. Methods: Participants were 41 male runners: 13 with brain impairments (RBI) and 28 non-disabled (NDR). All participants completed a maximal 60-m sprint and a novel battery of three lower limb isometric strength tests. Results: RBI showed significantly lower strength scores compared with NDR on the more affected side in leg flexion (176 vs. 243 N), leg extension (993 vs. 1661 N) and plantarflexion (824  vs. 1457 N). Significant differences were also seen on the less affected side in plantarflexion (1072 vs. 1508 N). RBI were significantly slower in the acceleration phase (0–15 m) (3.2 s ± 0.3 vs. 2.8 s ± 0.2) and top speed phase (30−60 m) (4.3 s ± 0.6 vs. 3.8 s ± 0.3). Correlation analysis showed stronger relationships between strength and running performance in RBI than NDR; however, the correlations were not significant. Conclusions: This study evaluated measures to assess strength for the purposes of classification and found that the measures were significantly different in RBI compared with NDR indicating the tests were able to capture strength impairment in this population. This study indicates that strength may be an important impairment type to assess in this population, as impairments of muscle strength may influence the outcome of running performance in athletes with more severe impairments.

How much do range of movement and coordination affect Paralympic sprint performance

INTRODUCTION Development of evidence-based methods of paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and sports performance. To date, no such research has been conducted. The purpose of this study was to quantify the extent to which range of movement (ROM) and coordination affect running performance in runners with and without brain impairment. METHODS Participants were 41 male runners, 13 with brain impairments (RBI) and 28 nondisabled (NDR). All participants completed a maximal 60-m sprint as well as a novel battery of five lower limb ROM tests and three lower limb coordination tests. RESULTS In the coordination tests, RBI showed significantly slower mean movement times compared to NDR on all measures (e.g., 0.54 s ± 0.12 s vs 0.34 s ± 0.05 s). Runners with brain impairments had significantly lower range of movement on five of ten measures (e.g., 25.9° ± 5.4° vs 37.0° ± 6.0°) and had significantly slower acceleration (0-15 m) (3.2 s ± 0.3 s vs 2.8 s ± 0.2 s) and top speed (30-60 m) (4.3 s ± 0.6 s vs 3.8 s ± 0.3 s). Five ROM measures significantly correlated with sprint performance in RBI and did not significantly correlate with sprint performance in NDR, satisfying convergent and divergent validity criteria. These individual tests explained 38% to 58% of the variance in sprint performance in RBI. CONCLUSION This is the first study to quantify the extent to which eligible impairments affect performance in a paralympic sport. Five of the ROM measures significantly affected sprint performance in RBI and were deemed valid for the purposes of classifying impairments in classes T35-T38. This study is an important methodological step toward development of evidence-based methods of classifying impairments in classes T35-T38 and provides practical methodological guidance to researchers in this field.

Novel strength test battery to permit evidence-based paralympic classification.

AbstractOrdinal-scale strength assessment methods currently used in Paralympic athletics classification prevent the development of evidence-based classification systems. This study evaluated a battery of 7, ratio-scale, isometric tests with the aim of facilitating the development of evidence-based methods of classification. This study aimed to report sex-specific normal performance ranges, evaluate test–retest reliability, and evaluate the relationship between the measures and body mass.Body mass and strength measures were obtained from 118 participants—63 males and 55 females—ages 23.2 years ± 3.7 (mean ± SD). Seventeen participants completed the battery twice to evaluate test–retest reliability. The body mass–strength relationship was evaluated using Pearson correlations and allometric exponents.Conventional patterns of force production were observed. Reliability was acceptable (mean intraclass correlation = 0.85). Eight measures had moderate significant correlations with body size (r = 0.30–61). Allometric exponents were higher in males than in females (mean 0.99 vs 0.30).Results indicate that this comprehensive and parsimonious battery is an important methodological advance because it has psychometric properties critical for the development of evidence-based classification. Measures were interrelated with body size, indicating further research is required to determine whether raw measures require normalization in order to be validly applied in classification.

Identifying the performance characteristics of a winning outcome in elite mixed martial arts competition

OBJECTIVES To determine those performance indicators that have the greatest influence on classifying outcome at the elite level of mixed martial arts (MMA). A secondary objective was to establish the efficacy of decision tree analysis in explaining the characteristics of victory when compared to alternate statistical methods. DESIGN Cross-sectional observational. METHODS Eleven raw performance indicators from male Ultimate Fighting Championship bouts (n=234) from July 2014 to December 2014 were screened for analysis. Each raw performance indicator was also converted to a rate-dependent measure to be scaled to fight duration. Further, three additional performance indicators were calculated from the dataset and included in the analysis. Cohens d effect sizes were employed to determine the magnitude of the differences between Wins and Losses, while decision tree (chi-square automatic interaction detector (CHAID)) and discriminant function analyses (DFA) were used to classify outcome (Win and Loss). RESULTS Effect size comparisons revealed differences between Wins and Losses across a number of performance indicators. Decision tree (raw: 71.8%; rate-scaled: 76.3%) and DFA (raw: 71.4%; rate-scaled 71.2%) achieved similar classification accuracies. Grappling and accuracy performance indicators were the most influential in explaining outcome. The decision tree models also revealed multiple combinations of performance indicators leading to victory. CONCLUSIONS The decision tree analyses suggest that grappling activity and technique accuracy are of particular importance in achieving victory in elite-level MMA competition. The DFA results supported the importance of these performance indicators. Decision tree induction represents an intuitive and slightly more accurate approach to explaining bout outcome in this sport when compared to DFA.

Validity and reliability of a portable isometric mid-thigh clean pull

Abstract James, LP, Roberts, LA, Haff, GG, Kelly, VG, and Beckman, EM. Validity and reliability of a portable isometric mid-thigh clean pull. J Strength Cond Res 31(5): 1378–1386, 2017—This study investigated the test-retest reliability and criterion validity of force-time curve variables collected through a portable isometric mid-thigh clean pull (IMTP) device equipped with a single-axial load cell. Fifteen males with ≥6 months of resistance training experience attended two testing sessions. In each session, participants performed an IMTP in 2 separate conditions in a randomized counterbalanced manner. The criterion condition consisted of a closed-chain IMTP configured with a force plate (IMTPf), whereas the experimental test was undertaken using a portable IMTP with data acquired through a single-axial load cell (IMTPl). A very high reliability (coefficient of variation [CV] = 3.10, 90% confidence interval [CI]: 2.4–4.6%; intraclass correlation coefficient [ICC] = 0.96, 90% CI: 0.90–0.98) and acceptable validity (CV = 9.2, 90% CI: 7–14%; ICC = 0.88, 90% CI: 0.71–0.95) were found in the experimental condition for the measure of peak force. However, significant differences were present between the IMTPf and IMTPl (p < 0.0001). Alternate force-time curve variables did not reach acceptable levels of validity or reliability in the experimental condition. The IMTPl is a valid and highly reliable method for assessing peak force. This provides evidence supporting the use of an IMTPl as a cost-effective and portable alternative for those who wish to assess maximal force production in a similar fashion to a traditional IMTP. However, practitioners should be aware that these are slightly different tests.

Evaluation of methods for calculating maximum allowable standing height in amputees competing in Paralympic athletics.

The International Paralympic Committee has a maximum allowable standing height (MASH) rule that limits stature to a pre‐trauma estimation. The MASH rule reduces the probability that bilateral lower limb amputees use disproportionately long prostheses in competition. Although there are several methods for estimating stature, the validity of these methods has not been compared. To identify the most appropriate method for the MASH rule, this study aimed to compare the criterion validity of estimations resulting from the current method, the Contini method, and four Canda methods (Canda‐1, Canda‐2, Canda‐3, and Canda‐4). Stature, ulna length, demispan, sitting height, thigh length, upper arm length, and forearm length measurements in 31 males and 30 females were used to calculate the respective estimation for each method. Results showed that Canda‐1 (based on four anthropometric variables) produced the smallest error and best fitted the data in males and females. The current method was associated with the largest error of those tests because it increasingly overestimated height in people with smaller stature. The results suggest that the set of Canda equations provide a more valid MASH estimation in people with a range of upper limb and bilateral lower limb amputations compared with the current method.