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Morality- and Norm-Based Subgroups of Disability-Sport Athletes Differ on Their Anticipated Guilt and Intentions Toward Doping

Tyler S. Harris, Alan L. Smith, and Ian Boardley

The purpose of this study was to examine whether subgroups of disability-sport athletes exist on morality- and norm-based doping cognitions and whether these groups differ in anticipated guilt or doping intentions. A survey was completed by 186 athletes (M age = 37.5 years, 78.0% male, 45.1% wheelchair basketball) assessing norms, doping moral disengagement, anticipated guilt, and intentions to dope. Cluster analysis revealed four distinct subgroups of athletes, including one potentially high-risk subgroup characterized by relatively high scores on doping moral disengagement, subjective norms, and descriptive norms. One-way analysis of variance revealed significantly lower anticipated guilt in two athlete subgroups characterized by relatively higher doping moral disengagement than the other two subgroups. Moreover, the potentially high-risk group had a greater proportion of athletes showing some presence of intention to dope. This study suggests there is a small subgroup of disability-sport athletes at elevated risk of doping who might benefit from targeted antidoping interventions.

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Quantitative Muscle Fascicle Tractography Using Brightness-Mode Ultrasound

Hannah Kilpatrick, Emily Bush, Carly Lockard, Xingyu Zhou, Crystal Coolbaugh, and Bruce Damon

A muscle’s architecture, defined as the geometric arrangement of its fibers with respect to its mechanical line of action, impacts its abilities to produce force and shorten or lengthen under load. Ultrasound and other noninvasive imaging methods have contributed significantly to our understanding of these structure–function relationships. The goal of this work was to develop a MATLAB toolbox for tracking and mathematically representing muscle architecture at the fascicle scale, based on brightness-mode ultrasound imaging data. The MuscleUS_Toolbox allows user-performed segmentation of a region of interest and automated modeling of local fascicle orientation; calculation of streamlines between aponeuroses of origin and insertion; and quantification of fascicle length, pennation angle, and curvature. A method is described for optimizing the fascicle orientation modeling process, and the capabilities of the toolbox for quantifying and visualizing fascicle architecture are illustrated in the human tibialis anterior muscle. The toolbox is freely available.

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The Vehicle Seating Intervention Trial: Cross-Over Randomized Controlled Trial to Evaluate the Impact of 2 Car Seat Configurations on Spinal Posture

Diana De Carvalho, Kristi Randhawa, Leslie Verville, Sheilah Hogg-Johnson, Samuel J. Howarth, Carmen Liang, Silvano Mior, and Pierre Côté

Driving posture can lead to musculoskeletal pain. Most work focuses on the lower back; therefore, we know little about automobile seat design and neck posture. This study evaluated an automobile driver seat that individualized upper back support to improve head and neck posture. Specifically, we examined the system’s impact on anterior head translation with secondary outcomes of spine posture and perceptions of comfort/well-being compared with a control. Forty participants were block randomized to experience either the activated or deactivated version of the same seating system first. Participants completed two 30-minute simulated driving trials, separated by washout, with continuous measures of anterior head translation, spine posture, and pelvis orientation. Perceptions of comfort/well-being were assessed by survey and open-ended questions immediately following each condition. Small, but statistically significant decreases in anterior head translation and posterior pelvic tilt occurred with the activated seat system. Participants reported lower satisfaction with the activated seat system. Order of the 2 seat conditions affected differences in pelvis orientation and participant perceptions of comfort/well-being. An anthropometric-based seat system targeting upper back support can significantly affect head and pelvic posture but not satisfaction during simulated driving. Future work should examine long-term impacts of these posture changes on health outcomes.

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Volume 40 (2023): Issue 4 (Oct 2023)

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Volume 39 (2023): Issue 5 (Oct 2023): Special Issue: International Society of Biomechanics: 50 years of Musculoskeletal Biomechanics

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Volume 27 (2023): Issue 4 (Oct 2023)

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Variables Associated With Knee Valgus in Male Professional Soccer Players During a Single-Leg Vertical Landing Task

Matheus Vianna, Leonardo Metsavaht, Eliane Guadagnin, Carlos Eduardo Franciozi, Marcus Luzo, Marcio Tannure, and Gustavo Leporace

Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was .43 during the landing phase (P = .04) and with peak hip internal rotation was −.68 (P < .001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r = .40, P = .05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test.

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Reliability of Shoulder Helical Axes During Intransitive and Transitive Upper Limb Tasks

Paola Adamo, Federico Temporiti, Martina Maffeis, Francesco Bolzoni, and Roberto Gatti

Shoulder complex stability can be estimated in vivo through the analysis of helical axes (HAs) dispersion during upper limb movements. The study aimed at investigating test–retest reliability of shoulder HAs dispersion parameters during upper limb tasks. Twenty healthy volunteers performed 2 intransitive (shoulder flexion and rotation) and one transitive (combing) tasks with the dominant and nondominant upper limbs during 2 recording sessions at 1-week distance. Kinematics was detected through an optoelectronic system. Mean distance and mean angle (MA) were adopted as HAs dispersion indexes. Reliability was excellent for mean distance (intraclass correlation coefficient [ICC]: .91) and MA (ICC: .92) during dominant flexion, and good for MA (ICC: .90) during nondominant flexion. Moderate reliability was found for HAs parameters during rotation (ICCs from .70 to .59), except for MA during dominant rotation where reliability was poor. Reliability was good for mean distance (ICC: .83) and moderate for MA (ICC: .67) during the dominant combing task, whereas no reliability was found during the nondominant combing task. HAs dispersion parameters revealed high reliability during simple intransitive tasks with the dominant limb. Reliability decreased with the increase in task complexity due to the increase in movement variability. HAs dispersion technique could be used to assess shoulder complex stability in patients after rehabilitation or surgery.

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The History and Future of Neuromusculoskeletal Biomechanics

David G. Lloyd, Ilse Jonkers, Scott L. Delp, and Luca Modenese

The Executive Council of the International Society of Biomechanics has initiated and overseen the commemorations of the Society’s 50th Anniversary in 2023. This included multiple series of lectures at the ninth World Congress of Biomechanics in 2022 and XXIXth Congress of the International Society of Biomechanics in 2023, all linked to special issues of International Society of Biomechanics’ affiliated journals. This special issue of the Journal of Applied Biomechanics is dedicated to the biomechanics of the neuromusculoskeletal system. The reader is encouraged to explore this special issue which comprises 6 papers exploring the current state-of the-art, and future directions and roles for neuromusculoskeletal biomechanics. This editorial presents a very brief history of the science of the neuromusculoskeletal system’s 4 main components: the central nervous system, musculotendon units, the musculoskeletal system, and joints, and how they biomechanically integrate to enable an understanding of the generation and control of human movement. This also entails a quick exploration of contemporary neuromusculoskeletal biomechanics and its future with new fields of application.

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Stressors and Expected Performance of Soccer Athletes: The Role of Sport Confidence and Cognitive Appraisal

Catarina Morais, Clara Simães, A. Rui Gomes, and Beatriz M. Gonçalves

This study aimed to provide a framework for how athletes evaluate stress before a competition and how stress relates to cognitive appraisal, sport confidence, and expectations of performance. Participants were 327 youth male athletes, aged 15–19 years (M = 16.90; SD = 1.00), who competed in the Portuguese National Football League and completed a questionnaire 24–48 hr before their match, using the critical incident methodology. Results revealed that opponents were the main source of stress for athletes and that the more athletes stress about their opponents, the more they tend to perceive the situation as threatening (and less challenging), the lower their perceptions of coping and sport confidence which, in turn, predicted lower expectations of individual and collective performance. In sum, perceiving the stressful situation as either a challenge or a threat predicts young athletes’ sport confidence and, consequently, expected performance when dealing with stressful competitive situations.