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Jennifer A. Scarduzio, Christina S. Walker, Nicky Lewis and Anthony M. Limperos

This study examined how participants responded to incidents of athlete-perpetrated intimate partner violence in two separate contexts: one featuring an athlete from a league that is at peak popularity among sports audiences (National Football League; NFL) and one featuring an athlete from an up-and-coming league that currently has a lower standing in professional sports (Ultimate Fighting Championship League; UFC). The authors used the social ecological model to qualitatively analyze participant perceptions about athlete-perpetrated intimate partner violence composite news packages. For the purpose of this study specifically, they centered on 1,124 responses to one of the open-ended qualitative questions asked in a larger quantitative experiment. The authors found that the participants most frequently attributed the perpetrator’s behavior to either individual or relationship-level reasons and that there were differences in the level attributed for participants of different races and ethnicities. They also determined that the participants were more likely to ascribe the violence to the suspect’s job (i.e., athlete) if they were a UFC fighter than an NFL player. Theoretical extensions of the social ecological model and practical implications for journalists, the media, and fans are offered.

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Megan A. Kuikman, Margo Mountjoy, Trent Stellingwerff and Jamie F. Burr

Relative energy deficiency in sport (RED-S) can result in negative health and performance outcomes in both male and female athletes. The underlying etiology of RED-S is low energy availability (LEA), which occurs when there is insufficient dietary energy intake to meet exercise energy expenditure, corrected for fat-free mass, leaving inadequate energy available to ensure homeostasis and adequate energy turnover (optimize normal bodily functions to positively impact health), but also optimizing recovery, training adaptations, and performance. As such, treatment of RED-S involves increasing energy intake and/or decreasing exercise energy expenditure to address the underlying LEA. Clinically, however, the time burden and methodological errors associated with the quantification of energy intake, exercise energy expenditure, and fat-free mass to assess energy availability in free-living conditions make it difficult for the practitioner to implement in everyday practice. Furthermore, interpretation is complicated by the lack of validated energy availability thresholds, which can result in compromised health and performance outcomes in male and female athletes across various stages of maturation, ethnic races, and different types of sports. This narrative review focuses on pragmatic nonpharmacological strategies in the treatment of RED-S, featuring factors such as low carbohydrate availability, within-day prolonged periods of LEA, insufficient intake of bone-building nutrients, lack of mechanical bone stress, and/or psychogenic stress. This includes the implementation of strategies that address exacerbating factors of LEA, as well as novel treatment methods and underlying mechanisms of action, while highlighting areas of further research.

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Courtney M. Butowicz, Julian C. Acasio and Brad D. Hendershot

Altered trunk movements during gait in persons with lower-limb amputation are often associated with an increased risk for secondary health conditions; however, the postural control strategies underlying such alterations remain unclear. In this secondary analysis, the authors employed nonlinear measures of triplanar trunk accelerations via short-term Lyapunov exponents to investigate trunk local stability as well as spatiotemporal gait parameters to describe gait mechanics. The authors also evaluated the influence of a concurrent task on trunk local stability and gait mechanics to explore if competition for neuromuscular processing resources can assist in identifying unique strategies to control kinematic variability. Sixteen males with amputation—8 transtibial and 8 transfemoral—and 8 uninjured males (controls) walked on a treadmill at their self-selected speed (mean = 1.2 m/s ±10%) in 5 experimental conditions (8 min each): 4 while performing a concurrent task (2 walking and 2 seated) and 1 with no concurrent task. Individuals with amputation demonstrated significantly smaller Lyapunov exponents than controls in all 3 planes of motion, regardless of concurrent task or level of amputation (P < .0001). Individuals with transfemoral amputation walked with wider strides compared with individuals with transtibial amputation and controls (P < .0001). Individuals with amputation demonstrated more trunk kinematic variability in the presence of wider strides compared with individuals without amputation, and it appears that performing a concurrent cognitive task while walking did not change trunk or gait mechanics.

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Daniel Yang and Kathy Babiak

A specific form of corporate social responsibility—corporate philanthropy—has received little attention in sport scholarship despite the increased formalization of this business function in practice. Specifically, few studies have explored the institutional mechanisms that influence the corporate philanthropy of professional sport teams. Given that teams receive simultaneous institutional pressures from their league and from the community in which they operate, this study examined how the presence of multiple peers from different fields affected teams in terms of determining the appropriate level of philanthropic activity. The hypotheses were tested through a longitudinal analysis of philanthropic data from team foundations in four professional leagues in the United States from 2005 to 2017. The authors found that teams were more likely to be affected by the philanthropic giving levels of league peers than local peers. Overall, this study provides a better understanding of simultaneous institutional pressures shaping the philanthropic activities of professional sport teams.

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Xiyao Shan, Pavlos Evangelidis, Takaki Yamagishi, Shun Otsuka, Fumiko Tanaka, Shigenobu Shibata and Yasuo Kawakami

This study investigated (a) site- and direction-dependent variations of passive triceps surae aponeurosis stiffness and (b) the relationships between aponeurosis stiffness and muscle strength and walking performance in older individuals. Seventy-nine healthy older adults participated in this study. Shear wave velocities of the triceps surae aponeuroses at different sites and in two orthogonal directions were obtained in a prone position at rest using supersonic shear imaging. The maximal voluntary isometric contraction torque of the plantar flexors and normal (preferred) and fast (fastest possible) walking speeds (5-m distance) were also measured. The shear wave velocities of the adjoining aponeuroses were weakly associated with plantar flexion torque (r = .23–.34), normal (r = .26), and fast walking speed (r = .25). The results show clear spatial variations and anisotropy of the triceps surae aponeuroses stiffness in vivo, and the aponeurosis stiffness was associated with physical ability in older adults.

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Yumeng Li, Jupil Ko, Marika A. Walker, Cathleen N. Brown and Kathy J. Simpson

The purpose of the present study was to examine the effect of chronic ankle instability (CAI) on lower-extremity joint coordination and stiffness during landing. A total of 21 female participants with CAI and 21 pair-matched healthy controls participated in the study. Lower-extremity joint kinematics were collected using a 7-camera motion capture system, and ground reaction forces were collected using 2 force plates during drop landings. Coupling angles were computed based on the vector coding method to assess joint coordination. Coupling angles were compared between the CAI and control groups using circular Watson–Williams tests. Joint stiffness was compared between the groups using independent t tests. Participants with CAI exhibited strategies involving altered joint coordination including a knee flexion dominant pattern during 30% and 70% of their landing phase and a more in-phase motion pattern between the knee and hip joints during 30% and 40% and 90% and 100% of the landing phase. In addition, increased ankle inversion and knee flexion stiffness were observed in the CAI group. These altered joint coordination and stiffness could be considered as a protective strategy utilized to effectively absorb energy, stabilize the body and ankle, and prevent excessive ankle inversion. However, this strategy could result in greater mechanical demands on the knee joint.

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Matthew S. Briggs, Claire Spech, Rachel King, Mike McNally, Matthew Paponetti, Sharon Bout-Tabaku and Laura Schmitt

Obese (OB) youth demonstrate altered knee mechanics and worse lower-extremity performance compared with healthy weight (HW) youth. Our objectives were to compare sagittal plane knee landing mechanics between OB and HW youth and to examine the associations of knee and hip extension peak torque with landing mechanics in OB youth. Twenty-four OB and 24 age- and sex-matched HW youth participated. Peak torque was measured and normalized to leg lean mass. Peak knee flexion angle and peak internal knee extension moment were measured during a single-leg hop landing. Paired t tests, Pearson correlation coefficients, and Bonferroni corrections were used. OB youth demonstrated worse performance and lower knee extension (OB: 12.76 [1.38], HW: 14.03 [2.08], P = .03) and hip extension (OB: 8.59 [3.13], HW: 11.10 [2.89], P = .005) peak torque. Furthermore, OB youth demonstrated lower peak knee flexion angles (OB: 48.89 [45.41 to 52.37], HW: 56.07 [52.59 to 59.55], P = .02) and knee extension moments (OB: −1.73 [−1.89 to −1.57], HW: −2.21 [−2.37 to −2.05], P = .0001) during landing compared with HW youth. Peak torque measures were not correlated with peak knee flexion angle nor internal knee extension moment during landing in either group (P > .01). OB youth demonstrated altered landing mechanics compared with HW youth. However, no associations among peak torque measurements and knee landing mechanics were present.

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Jereme B. Outerleys, Michael J. Dunbar, Glen Richardson, Cheryl L. Hubley-Kozey and Janie L. Astephen Wilson

Total knee arthroplasty (TKA) surgery improves knee joint kinematics and kinetics during gait for most patients, but a lack of evidence exists for the level and incidence of improvement that is achieved. The objective of this study was to quantify patient-specific improvements in knee biomechanics relative to osteoarthritis (OA) severity levels. Seventy-two patients underwent 3-dimensional (3D) gait analysis before and 1 year after TKA surgery, as well as 72 asymptomatic adults and 72 with moderate knee OA. A combination of principal component analysis and discriminant analyses were used to categorize knee joint biomechanics for patients before and after surgery relative to asymptomatic, moderate, and severe OA. Post-TKA, 63% were categorized with knee biomechanics consistent with moderate OA, 29% with severe OA, and 8% asymptomatic. The magnitude and pattern of the knee adduction moment and angle (frontal plane features) were the most significant contributors in discriminating between pre-TKA and post-TKA knee biomechanics. Standard of care TKA improves knee biomechanics during gait to levels most consistent with moderate knee OA and predominately targets frontal plane features. These results provide evidence for the level of improvement in knee biomechanics that can be expected following surgery and highlight the biomechanics most targeted by surgery.

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Jennifer T. Coletti, Veronica Allan and Luc J. Martin

A child’s first contact with media and culture typically comes from books they are exposed to in the home and at school. The narratives presented contribute to the early reinforcement of gender roles and norms and can greatly influence the way that young girls perceive and experience sport. The purpose of this study was to explore the narratives within sport-based books geared toward a young female audience to determine the extent to which they promote the engagement of girls in sport. A pragmatic literature search was conducted to obtain books that met our inclusion criteria. Books (n = 28) were analyzed based on the age of their intended audience (aged 3–5, 6–8, and 9–12 years) using thematic narrative analysis. Although the authors promoted the engagement of girls in sport, underlying gender stereotypes were nevertheless salient. Across the books, themes involved the emphasis of “feminine” sports as a context for diversity and learning, the need to understand development as a process, the importance of relationships, and implications pertaining to perceptions of capability as female athletes. Most importantly, the application of a critical feminist lens enabled us to identify an underlying theme—the reinforcement of gender stereotypes—that permeated the storylines and served to undermine the potential adaptive messaging intended by authors. These findings suggest the need for greater attention toward the complexity of female sport and a cultural shift in thinking toward gender equity rather than simply increasing sport access for female participants.