Biomechanical analysis can effectively identify factors associated with task performance and injury risk, but often does not account for the interaction among the components that underlie task execution. Uncontrolled manifold (UCM) analyses were applied to data from 38 female, adolescent athletes performing single-leg drop landings and were used to differentiate successful and unsuccessful task performance by examining the frontal plane joint variance within the UCM (V UCM) that stabilized the horizontal center of mass position (V UCM) and within the orthogonal subspace (V ORT). The UCM revealed stronger coordination, indicated by the V UCM/V ORT ratio, in the successful condition. This may inform future research examining reduced motor coordination in failed movement tasks and its relation to injury risk and allow for targeted interventions that consider coordination processes rather than joint-specific outcomes.
Christopher A. DiCesare, Scott Bonnette, Gregory D. Myer and Adam W. Kiefer
Grace C. Bellinger, Kristen A. Pickett and Andrea H. Mason
Reaching and grasping are often completed while walking, yet the interlimb coordination required for such a combined task is not fully understood. Previous studies have produced contradictory evidence regarding preference for support of the lower limb ipsilateral or contralateral to the upper limb when performing a reaching task. This coordinative aspect of the combined task provides insight into whether the two tasks are mutually modified or if the reach is superimposed upon normal arm swinging. Collectively, 18 right-handed young adults walked slower, took shorter steps, and spent more time in double support during the combined task compared with walking alone. The peak grasp aperture was larger in walking reach-to-grasp trials compared with standing trials. There was not a strong trend for lower limb support preferences at the reach initiation or object contact. The participants could begin walking with either foot and demonstrated variability of preferred gait initiation patterns. There was a range of interlimb coordination patterns, none of which could be generalized to all young adults. The variability with which healthy right-handed young adults execute a combined walking reach-to-grasp task suggests that the cyclical (walking) and discrete (prehension) motor tasks may have separate motor control mechanisms, as proposed in the two primitives theory.
James Hackney, Jade McFarland, David Smith and Clinton Wallis
Most studies of high-speed lower body movements include practice repetitions for facilitating consistency between the trials. We investigated whether 20 repetitions of drop landing (from a 30.5-cm platform onto a force plate) could improve consistency in maximum ground reaction force, linear lower body stiffness, depth of landing, and jump height in 20 healthy, young adults. Coefficient of variation was the construct for variability used to compare the first to the last five repetitions for each variable. We found that the practice had the greatest effect on maximum ground reaction force (p = .017), and had smaller and similar effects on lower body stiffness and depth of landing (p values = .074 and .044, respectively), and no measurable effect on jump height. These findings suggest that the effect of practice on drop landing differs depending upon the variable measure and that 20 repetitions significantly improve consistency in ground reaction force.
ZáNean McClain, E. Andrew Pitchford and Jill Pawlowski
Rafael L. Kons, Kai Krabben, David L. Mann, Gabriela Fischer and Daniele Detanico
In judo competition for visual impairment, athletes of different classes compete against each other in the same category; B1 athletes are totally blind, whereas B2 and B3 athletes are partially sighted. To test for potential competition disparities due a single category of athletes, this study aimed to compare competitive and technical–tactical performance in visually impaired judo athletes with different degrees of visual impairment. The authors analyzed 340 judo matches from the 2012 and 2016 Paralympic Games. The scores, penalties, efficiency index, and types of medals were examined, as well as the technical variation and temporal structure. The main finding was that blind judo athletes presented lower scores (p < .05; effect size [ES] = 0.43–0.73), medals (p < .05), and efficiency (p < .05; ES = 0.40–0.73); different patterns of play; and a shorter time to lose than partially sighted athletes (p = .027; ES = 0.10–0.14). However, the penalties were similar between classes (p > .05; ES = 0.07–0.14). The odds ratio of a winning medal was 3.5–8 times less in blind athletes than in partially sighted athletes (p < .01). In conclusion, blind judo athletes presented lower competitive and technical–tactical performance than athletes with some residual functional vision. These findings provide support for the development of new evidence-based criteria for judo classification based on vision impairment.
Rachael C. Stone, Shane N. Sweet, Marie-Josée Perrier, Tara MacDonald, Kathleen A. Martin Ginis and Amy E. Latimer-Cheung
Identifying as a regular exerciser has been found to effectively alter stereotypes related to warmth and competence for adults with a physical disability; however, it remains unclear how sport participation can influence this trend. Therefore, this study aimed to examine warmth and competence perceptions of adults with a physical disability portrayed as elite and nonelite athletes relative to other athletic and nonathletic subgroups of adults with and without a physical disability in the context of the stereotype content model. Using survey data from able-bodied participants (N = 302), cluster analyses were applied to a behaviors from intergroup affect and stereotypes map for displaying the intersection of warmth and competence perceptions. The results demonstrated that adults with a physical disability who are described as elite athletes (i.e., Paralympians) are clustered with high warmth and high competence, similar to their able-bodied athletic counterparts (i.e., Olympians). The findings suggest that perceiving athletic and elite sport statuses for adults with a physical disability may counter the stereotypes commonly applied to this group.
Paul E. Yeatts, Ronald Davis, Jun Oh and Gwang-Yon Hwang
Participation in physical activity has been shown to improve components of psychological well-being (i.e., affect). Programs such as the Warrior Games have been designed to promote physical activity in wounded military personnel. However, sport competition typically yields a winner and a loser (i.e., game outcome). The experience of a win or a loss may affect how wounded athletes respond to game outcome. Therefore, the purpose of this study was to investigate the affective changes (positive affect, negative affect, tranquility, and fatigue) according to game outcome in a sample of wounded military wheelchair basketball players participating in a weekend tournament. The results indicated that the participants who experienced a win reported significantly higher positive affect and tranquility and significantly lower negative affect than those experiencing a loss. These findings have important implications for wounded veteran athletes, as well as coaches and administrative personnel.
Mohsen Shafizadeh, Nicola Theis and Keith Davids
The aim of this study was to examine strategies to absorb impact shock during RaceRunning in participants with neurological motor disorders. For this purpose, 8 RaceRunning athletes (4 male and 4 female) voluntarily took part in the study. Each participant performed a series of 100-m sprints with a RaceRunning bike. Acceleration of the tibia and head was measured with 2 inertial measurement units and used to calculate foot-impact shock measures. Results showed that RaceRunning pattern was characterized by a lack of impact peak in foot–ground contact time and the existence of an active peak after foot contact. Due to the ergonomic properties of the RaceRunning bike, shock is attenuated throughout the stance phase. In conclusion, the results revealed that RaceRunning athletes with neurological motor disorders are capable of absorbing impact shock during assisted RaceRunning using a strategy that mimics runners without disabilities.
Cédrick T. Bonnet
In an upright stance, individuals sway in unpredictable ways. Their eyes also move in unpredictable ways in fixation tasks. The objective of this study was to analyze visual functions, postural control, and cognitive involvement in stationary gaze. A total of 14 healthy young adults performed a fixation task and a free-viewing task (three trials per task, 45 s per trial). As expected, the results showed many (n = 32) significant positive Pearson correlation coefficients between the eye and center of pressure/body (head, neck, and lower back) movements in the fixation task. In the free-viewing task, the correlations were nonsignificant. Only 3 of the 32 significant correlations (9.4%) were significantly related to cognitive involvement (measured with a subjective questionnaire). These results indirectly strengthened the validity of the synergistic model of postural control.
Jeffrey Martin, Mario Vassallo, Jacklyn Carrico and Ellen Armstrong
The purpose of this study was to predict Paralympian swimmers’ happiness as a result of winning 2016 Paralympic medals. Understanding potential antecedents of athletes’ happiness has theoretical and practical value. Medal winners (N = 138) had their facial expressions rated for happiness at the race finish. Three predictors were examined: finish place (i.e., first, second, or third), swimmers’ expectations for race place, and race time. A multiple-regression analysis predicting happiness was significant, F(3, 98) = 3.66, p < .015, accounting for 10% of the variance. Significant beta weights for race place (β = −0.551) and finishing higher than their 2015 world ranking (β = 0.551) indicated that higher-finishing swimmers were happier than lower-finishing swimmers, and swimmers who finished better than their 2015 ranking were happier than swimmers who finished lower than their ranking. The authors also found partial support for the counterfactual-thinking hypothesis for male swimmers and evidence of gender and country differences in happiness.