This study examined sex differences in head kinematics and neck muscle activity during sudden head perturbations. Sixteen competitive ice hockey players participated. Three muscles were monitored bilaterally using surface electromyography: sternocleidomastoid, scalene, and splenius capitis. Head and thorax kinematics were measured. Head perturbations were induced by the release of a 1.5-kg weight attached to a wire wrapped around an adjustable pulley secured to the participant’s head. Perturbations were delivered in 4 directions (flexion, extension, right lateral bend, and left lateral bend). Muscle onset times, muscle activity, and head kinematics were examined during 3 time periods (2 preperturbation and 1 postperturbation). Females had significantly greater head acceleration during left lateral bend (31.4%, P < .05) and flexion (37.9%, P = .01). Females had faster muscle onset times during flexion (females = 51 ± 11 ms; males = 61 ± 10 ms; P = .001) and slower onset times during left lateral bend and extension. Females had greater left/right sternocleidomastoid and scalene activity during extension (P = .01), with no difference in head acceleration. No consistent neuromuscular strategy could explain all directional sex differences. Females had greater muscle activity postperturbation during extension, suggesting a neuromuscular response to counter sudden acceleration, possibly explaining the lack of head acceleration differences.
Chadwick Debison-Larabie, Bernadette A. Murphy and Michael W.R. Holmes
Laura K. Fewell, Riley Nickols, Amanda Schlitzer Tierney and Cheri A. Levinson
The current study tested if athlete patients differed from non-athlete patients in measures of eating disorder (ED) and related pathology. Athlete (n = 91 in Study 1; n = 39 in Study 2) and non-athlete (n = 76 in Study 1; n = 26 in Study 2) patients completed self-report measures, and body mass index (BMI) was calculated. Athlete patients had significantly lower ED symptomatology and depression than non-athlete patients (ps < .05). ED impairment, worry, psychosocial functioning, BMI, obsessive-compulsiveness, and compulsive exercise did not significantly differ between groups (ps > .08). Greater ED symptomatology was associated with higher psychosocial functioning among athlete patients and higher obsessive-compulsive symptoms and compulsive exercise among non-athlete patients. This is a novel study comparing ED symptomatology and related measures of mental health in athlete and non-athlete patients engaged in residential or partial hospitalization ED treatment. Future research should further investigate how participation in high-level sport impacts the presentation, treatment, and outcome of individuals with EDs.
Uta Kraus, Sophie Clara Holtmann and Tanja Legenbauer
Disordered eating in athletes has been frequently studied with a particular emphasis on aesthetic sports. Lately, competitive rowing has come into the focus. It has been supposed that in competitive rowers eating disturbances occur more frequently compared to non-competitive rowers. The aim of the present study therefore is to investigate eating disturbances and mental health related issues in competitive and non-competitive rowers. N = 45 lightweight (LWR), n = 31 heavyweight (HWR) and n = 37 non-competitive rowers (NCR) participated in an online based survey during the beginning of the on-season asking for eating behaviour (SCOFF, EDI-2) and mental health problems (PHQ). Results showed that competitive rowers reported more eating disturbances and risky attitudes/behaviour compared to non-competitive rowers. LWR showed higher Drive for thinness compared to HWR. The regression analysis revealed that Drive for thinness and Bulimia predict eating disorder symptoms in rowers. These results emphasize the presence of serious eating disturbances in competitive rowing.
Jenny H. Conviser, Amanda Schlitzer Tierney and Riley Nickols
Eating disorders (EDs) and disordered-eating behaviors (DEBs), pose a high risk of morbidity and mortality, threatening physical health, emotional health, and overall quality of life. Unfortunately, among athletes, prevalence rates continue to increase. This document summarizes the challenges of establishing and navigating the multidisciplinary care needed to effectively treat EDs and DEBs among athletes. The benefits of timely and frequent communication within the multidisciplinary treatment team (MDTT) are emphasized and discussed. Authors advise who should be selected as members of the MDTT and suggest that all personnel, including athletic coaches, athletic trainers, physical therapists, and certified fitness professionals be ED-informed and ED-sensitive. Vital components of care are noted including use of a variety of evidence-based psychotherapeutic modalities, interventions which target emotional regulation, and prioritize values based compassionate care. Authors caution that performance decrements and medical/physiological changes are not always easily observable in individuals with EDs and DEBs and therefore, attuned, consistent, and ongoing monitoring is needed. Consensus regarding previously established parameters for return to play and careful titration of physical activity throughout the ED recovery process are suggested as important for preserving health, preventing re-injury, or relapse and facilitating successful return to sport participation.
Katie A. Conway, Randall G. Bissette and Jason R. Franz
Aging and many gait pathologies are characterized by reduced propulsive forces and ankle moment and power generation during trailing leg push-off in walking. Despite those changes, we posit that many individuals retain an underutilized reserve for enhancing push-off intensity during walking that may be missed using conventional dynamometry. By using a maximum ramped impeding force protocol and maximum speed walking, we gained mechanistic insight into the factors that govern push-off intensity and the available capacity thereof during walking in young subjects. We discovered in part that young subjects walking at their preferred speed retain a reserve capacity for exerting larger propulsive forces of 49%, peak ankle power of 43%, and peak ankle moment of 22% during push-off—the latter overlooked by maximum isometric dynamometry. We also provide evidence that these reserve capacities are governed at least in part by the neuromechanical behavior of the plantarflexor muscles, at least with regard to ankle moment generation. We envision that a similar paradigm used to quantify propulsive reserves in older adults or people with gait pathology would empower the more discriminate and personalized prescription of gait interventions seeking to improve push-off intensity and thus walking performance.
Andrea S. Hartmann, Florian Steenbergen, Silja Vocks, Dirk Büsch and Manuel Waldorf
Fitness training to attain the lean body ideal is becoming increasingly popular among women. However, it remains unclear how the drive for leanness (DL), as compared to the drives for thinness (DT) and muscularity (DM), relates to body image pathology and substance use in female weight-trainers. Participants (N = 168) completed a survey assessing DL, DT, DM, eating and body dysmorphic disorder pathology, and substance use. DT and DM were related to eating disorder and body dysmorphic disorder symptoms (all r ≥ .29; all ps < .01), while DL only to the former (r = .19, p < .05). Supplement use was associated with DL and DM (r = .17 and .55; both p < .01) and pharmaceutical use with DT and DM (r ≥ .21; both p < .01). Female weight-trainers should not be neglected in body image disorder prevention, with a particular focus on DT and DM.
Hiroaki Hobara, Sakiko Saito, Satoru Hashizume, Hiroyuki Sakata and Yoshiyuki Kobayashi
To understand the step characteristics during sprinting in lower-extremity amputees using running-specific prosthesis, each athlete should be investigated individually. Theoretically, sprint performance in a 100-m sprint is determined by both step frequency and step length. The aim of the present study was to investigate how step frequency and step length correlate with sprinting performance in elite unilateral transtibial amputees. By using publicly-available Internet broadcasts, the authors analyzed 88 races from 7 unilateral transtibial amputees. For each sprinter’s run, the average step frequency and step length were calculated using the number of steps and official race time. Based on Pearson’s correlation coefficients between step frequency, step length, and official race time for each individual, the authors classified each individual into 3 groups: step-frequency reliant, step-length reliant, and hybrid. It was found that 2, 2, and 3 sprinters were classified into step-frequency reliant, step-length reliant, and hybrid, respectively. These results suggest that the step frequency or step length reliance during a 100-m sprint is an individual occurrence in elite unilateral transtibial amputees using running-specific prosthesis.
Dana K. Voelker and Justine J. Reel
The purpose of this qualitative investigation was to examine male competitive figure skaters’ experiences of weight pressure in sport. Specifically, male skaters’ perceptions of the ideal skating body, sources of weight pressure in elite figure skating, and the perceived role of their sport in shaping body image, athletic performance, eating, and exercise behaviors were explored. Through a social constructivist lens, an inductive thematic analysis was used to examine the contextual influences of the skating environment. Thirteen male figure skaters ages 16–24 (M = 18.53, SD = 3.33) with an average 10.38 years of skating experience (SD = 4.05) were interviewed. Skaters identified the parameters for the ideal body in skating along with specific weight pressures, body image concerns, and weight management strategies. Similar to female skaters, male skaters perceived that body image affected psychological factors that influence sport performance. Sport psychologists and consultants should be attentive to the skating environment and how specific performance and appearance demands may influence an athlete’s mindset.
Hai-Jung Steffi Shih, Danielle N. Jarvis, Pamela Mikkelsen and Kornelia Kulig
Bipedal tasks require interlimb coordination that improves with practice and acquisition of skills. The purpose of this study was to compare interlimb force coordination during dance-specific rate-controlled consecutive bipedal jumps (sautés) between expert dancers and nondancers. To analyze coordination of vertical ground reaction forces recorded under each leg, the vector coding approach was used. Although there were no differences in the patterns of interlimb force coordination between groups, the dancers exhibited less variability of interlimb force coordination during the transition phase from weight acceptance to propulsion as well as during the propulsion phase itself. The interlimb force coordination variability was associated with task performance only during the transition phase, which highlights the potential importance of control during this phase. In conclusion, expert dancers were better at reducing interlimb force coordination variability during the task-relevant transition phase, which was related to better performance at maintaining jump rate and jump height consistency.
Hardeep Singh, Mark Lee, Matthew J. Solomito, Christian Merrill and Carl Nissen
Symptomatic spondylolysis/spondylolisthesis is thought to be caused by repetitive lumbar extension. About 8.9% of baseball pitchers that experience back pain will be diagnosed with spondylolysis. Therefore, this study aims to identify and quantify lumbar extension experienced during baseball pitching. It was hypothesized that young pitchers would exhibit less lumbar extension than older pitchers. A total of 187 healthy pitchers were divided into 3 age groups: youth, adolescent, and college. Kinematic data were collected at 250 Hz using a 3-D motion capture system. Lumbar motion was calculated as the difference between upper thoracic motion and pelvic motion over the pitching cycle. Lumbar “hyperextension” was defined as ≥20° past neutral. College pitchers had significantly greater lumbar extension compared with youth and adolescent pitchers at the point of maximum external rotation of the glenohumeral joint during the pitch cycle (−25° [13°], P = .04). For all age groups, lumbar hyperextension was present during the first 66% of the pitch cycle. Most pitchers spent 45% of pitch cycle in ≥30° of lumbar extension. Understanding that lumbar extension and hyperextension are components of the complex, multiplanar motions of the spine associated with baseball pitching can potentially help in both the prevention and management of symptomatic spondylolysis/spondylolisthesis.