Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques. Sports Biomech 2018;18:470-481. [PMID: 29578380 DOI: 10.1080/14763141.2018.1433871]

The Underlying Mechanisms of Sports Injuries in Paralympic Goalball: A Mixed-Method Study

OBJECTIVE

Data from the Paralympic Games indicate a fluctuating injury incidence in the Paralympic sport goalball, but the mechanisms behind have not been explored. The aims of this study are to (1) quantitatively analyze goalball injuries reported in the London 2012 and Rio 2016 Paralympic Games, (2) qualitatively explain the differences between both games, and (3) qualitatively assess general injury mechanisms and prevention opportunities of injuries in Goalball.

DESIGN

This is a mixed-method study. Injury incidence rates were analyzed from data collected during the 2012 and 2016 Paralympic Games. Then, semistructured interviews of games participants qualitatively explored injury mechanisms and prevention opportunities.

RESULTS

A reduction of injuries occurred from 2012 (incidence rate, 19.5; 95% confidence interval, 12.5-26.5) to 2016 (incidence rate: 5.6; 95% confidence interval, 1.7-9.5). In both games, acute traumatic injuries were most common. Female athletes reported higher rate of injuries compared with males ( P = 0.05). Qualitative data revealed that causes of injuries were collisions, overuse, and poor physical conditioning. The differences between the two games were explained by equipment, environment, and preparations.

CONCLUSIONS

The result from this study indicates that injuries in goalball are multifactorial. Ultimately, the mixed-method data from this study can help the sports context develop prevention measures.

Current Technologies and Practices to Assess External Training Load in Paralympic Sport: A Systematic Review

CONTEXT

Knowing the methods to assess the external load in Paralympic sports can help multidisciplinary teams rely on scientific evidence to better prescribe and monitor the athlete's development, improving sports performance and reducing the risk of injury/illness of Paralympic athletes.

OBJECTIVES

This review aimed to systematically explore the current practices of quantifying the external load in Paralympic sports and provide an overview of the methods and techniques used.

EVIDENCE ACQUISITION

A search in PubMed, Web of Science, Scopus, and EBSCO was carried out until November 2022. The measures of interest were objective methods for quantifying the external load of training or competition. The inclusion criteria for the studies were as follows: (1) peer-reviewed article; (2) the population were Paralympic athletes; (3) evaluated during training or competition; (4) reported at least one external load measure; and (5) published in English, Portuguese, or Spanish.

EVIDENCE SYNTHESIS

Of the 1961 articles found, 22 were included because they met the criteria, and 8 methods were identified to quantify the external load in training or competition in 8 Paralympic sports. The methods varied according to the characteristics of the Paralympic sports. To date, the devices used included an internal radiofrequency-based tracking system (wheelchair rugby) a miniaturized data logger (wheelchair tennis, basketball, and rugby); a linear position transducer (powerlifting and wheelchair basketball); a camera (swimming, goalball, and wheelchair rugby); a global positioning system (wheelchair tennis); heart rate monitors that assess external load variables in set (paracycling and swimming) and an electronic timer (swimming).

CONCLUSIONS

Different objective methods were identified to assess the external load in Paralympic sports. However, few studies showed the validity and reliability of these methods. Further studies are needed to compare different methods of external load quantification in other Paralympic sports.

Factors Associated With Penalty Outcome on Male Elite Goalball

The authors' purpose was to examine the factors associated with penalty outcomes of male elite goalball. A total of 122 video-recorded matches from two Paralympic Games (i.e., 2012 and 2016) and the 2014 Goalball World Championship were assessed using notational analysis. Individual (n = 2), situational (n = 4), and performance variables (n = 7) were analyzed with good strength of agreement for intra- and interrater kappa index values. Their results showed that penalties play a very important role in the final score, composing around 25% of total goals in elite goalball matches. Winners were awarded on average with 62% of penalties and had 66% effectiveness compared with losers (31% and 53%) or drawers (8% and 52%). Based on the authors' findings, penalty takers should direct their throws at specific target sectors on the court, which could increase their rate of success to over 80%.

Relationships between Different Field Test Performance Measures in Elite Goalball Players

Goalball is a Paralympic sport involving people with visual impairment. Little is known about the physical fitness of elite players of this sport, as previous studies only evaluated body composition and aerobic capacity. Thus, the aim of this study was to describe the performance of elite goalball players in different physical tests and to look for relationships between them. Eleven elite Brazilian goalball players, seven males and four females, were evaluated for body composition, maximal handgrip isometric force (MHGF), countermovement jump (CMJ), throwing velocity (TV) and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Players produced 41.54 ± 8.41 kgf in MHGF, 34.81 ± 7.2 cm in CMJ, 14.21 ± 1.89 m∙s⁻¹ in TV, and 505 ± 313 m in Yo-Yo IR1, with an estimated maximum oxygen consumption (VO₂max) of 40.64 ± 2.63 mL∙kg⁻¹∙min⁻¹. Most performance tests exhibited moderate to high correlations among them, while the percentage of body fat correlated with both the CMJ and Yo-Yo IR1 results. The current study reveals that CMJ could be a valuable monitoring tool as it was correlated with all other performance tests. The highest correlation observed was with TV (r = 0.754; p < 0.05), which is a key capacity in goalball. Moreover, high levels of body fat could be detrimental to anaerobic performance.

Relationships Between Aerobic and Anaerobic Parameters With Game Technical Performance in Elite Goalball Athletes

Our aims were to compare physiological parameters from the laboratory environment (LaB) and simulated goalball games (GaM), test relationships between physiological parameters in the laboratory and game technical performance (GTP), and examine the associations between physiological and technical responses during games. Seven elite athletes from the Brazilian National Team performed in LaB environment; (i) an incremental test to determine peak oxygen consumption (O_2PEAK), its corresponding speed, and peak blood lactate concentration and (ii) submaximal and supramaximal efforts to estimate maximal anaerobic contribution (AnC). In GaM condition, simulated games were also performed to determine physiological responses throughout the game, and to analyze the GTP (number of throws, defenses, recovery, and density of actions). No correlations (unclear) were found between laboratory and games analyses for O_2PEAK [47.3 (17.2) vs. 25.8 (18.2) mL⋅Kg^-1⋅min^-1], peak blood lactate concentrations [10.2 (5.4) vs. 2.0 (0.7) mM], and total AnC [21.0 (14.0) vs. 4.8 (6.1) mL Kg^-1]. O_2PEAK in the laboratory condition presented very likely correlations with throw and recovery frequency in games (r = -0.87 and confidence interval [CI] = 0.41; r = -0.90 and CI = 0.35; respectively). Oxygen consumption remained above baseline while blood lactate concentration remained unchanged during the games. The very likely correlation between anaerobic alactic contribution and action density (r = 0.95 and CI = 0.25) highlights the importance of the alactic metabolism. In general, our study demonstrates that goalball can be characterized as a high-intensity intermittent effort, where athlete performance is based on aerobic metabolism predominance while determinant actions are supplied by the anaerobic alactic metabolism. Specifically, higher values of LaB vs. GaM highlighted the need for standardization of specific protocols for goalball evaluation, mainly for the reproduction of ecologically valid values. In addition, O_2PEAK correlated with recovery frequency in the LaB condition, demonstrating that passive or low-intensity recovery between actions is fundamental to maintain performance.