Shinji Yamaguchi, Yujiro Kawata, Yuka Murofushi, Nobuto Shibata, and Tsuneyoshi Ota
This study examined the stress coping strategies of athletes with high psychological vulnerability. The participants were 487 university athletes (mean age = 19.8 years, SD = 0.88, 153 women). Data were collected using the Vulnerability Scale for University Athletes and General Coping Questionnaire and analyzed by conducting a multivariate analysis of variance. The results showed significant relationships between vulnerability and coping strategies (r = .11−.39). Vulnerability was most strongly related to the emotional support seeking aspect of emotion-oriented coping (r = .39). There was no significant difference in cognitive reinterpretation (r = .07). Vulnerability had a stronger relationship with emotion-oriented than problem-oriented coping, and high (vs. low) vulnerability athletes had significantly higher emotion-oriented-coping scores. These results suggest that vulnerable athletes need to be provided with appropriate emotional support to cope with stressful situations, as they rely heavily on a stress management strategy focusing on emotion regulation.
Tatiana Tapajcikova, Dávid Líška, Ladislav Batalik, Clea P. Tucker, and Alena Kobesova
High-quality sensory perception and body scheme (somatognosis) are important aspects for sport performance. This study compares stereognosis, body scheme, and kinesthesia in a group of 36 competitive karate athletes against a control group of 32 general population participants. The stereognosis Petrie test, two body scheme tests, and three kinesthesia tests served as outcome measurement tools. No significant difference was found in the stereognosis Petrie test, for the dominant (p = .389) or the nondominant (p = .791) hand, nor in the kinesthesia test (dominant, p = .661 and nondominant, p = .051). Karate athletes performed significantly better in the body scheme tests, that is, fist width estimation (p = .024) and shoulder width estimation (p = .019), as well as in karate-specific kinesthesia tests, that is, single punch (p = .010) and triple punch (p = .001). This study confirms competitive karate athletes have significantly better somatognosis, and better accuracy when performing quick dynamic movements compared with the general population.
Megan J. Schroeder, Samuel A. Acuña, Chandramouli Krishnan, and Yasin Y. Dhaher
Changes in knee mechanics following anterior cruciate ligament (ACL) reconstruction are known to be magnified during more difficult locomotor tasks, such as when descending stairs. However, it is unclear if increased task difficulty could distinguish differences in forces generated by the muscles surrounding the knee. This study examined how knee muscle forces differ between individuals with ACL reconstruction with different graft types (hamstring tendon and patellar tendon autograft) and “healthy” controls when performing tasks with increasing difficulty. Dynamic simulations were used to identify knee muscle forces in 15 participants when walking overground and descending stairs. The analysis was restricted to the stance phase (foot contact through toe-off), yielding 162 separate simulations of locomotion in increasing difficulty: overground walking, step-to-floor stair descent, and step-to-step stair descent. Results indicated that knee muscle forces were significantly reduced after ACL reconstruction, and stair descent tasks better discriminated changes in the quadriceps and gastrocnemii muscle forces in the reconstructed knees. Changes in quadriceps forces after a patellar tendon graft and changes in gastrocnemii forces after a hamstring tendon graft were only revealed during stair descent. These results emphasize the importance of incorporating sufficiently difficult tasks to detect residual deficits in muscle forces after ACL reconstruction.
Samuel E. Masters and John H. Challis
Soft tissue moves relative to the underlying bone during locomotion. Research has shown that soft tissue motion has an effect on aspects of the dynamics of running; however, little is known about the effects of soft tissue motion on the joint kinetics. In the present study, for a single subject, soft tissue motion was modeled using wobbling components in an inverse dynamics analysis to access the effects of the soft tissue on joint kinetics at the knee and hip. The added wobbling components had little effect on the knee joint kinetics, but large effects on the hip joint kinetics. In particular, the hip joint power and net negative and net positive mechanical work at the hip was greatly underestimated when calculated with the model without wobbling components compared with that of the model with wobbling components. For example, for low-frequency wobbling conditions, the magnitude of the peak hip joint moments were 50% greater when computed accounting the wobbling masses compared with a rigid body model, while for high-frequency wobbling conditions, the peaks were within 15%. The present study suggests that soft tissue motion should not be ignored during inverse dynamics analyses of running.
Hamid Norasi, Jordyn Koenig, and Gary A. Mirka
The electromyographic (EMG) normalization (often to maximum voluntary isometric contraction [MVIC]) is used to control for interparticipant and day-to-day variations. Repeated MVIC exertions may be inadvisable from participants’ safety perspective. This study developed a technique to predict the MVIC EMG from submaximal isometric voluntary contraction EMG. On day 1, 10 participants executed moment exertions of 100%, 60%, 40%, and 20% of the maximum (biceps brachii, rectus femoris, neck flexors, and neck extensors) as the EMG data were collected. On day 2, the participants replicated the joint moment values from day 1 (60%, 40%, and 20%) and also performed MVIC exertions. Using the ratios between the MVIC EMGs and submaximal isometric voluntary contraction EMG data values established on day 1, and the day 2 submaximal isometric voluntary contraction EMG data values, the day 2 MVIC EMGs were predicted. The average absolute percentage error between the predicted and actual MVIC EMG values for day 2 were calculated: biceps brachii, 45%; rectus femoris, 27%; right and left neck flexors, 27% and 33%, respectively; and right and left neck extensors, both 29%. There will be a trade-off between the required accuracy of the MVIC EMG and the risk of injury due to exerting actual MVIC. Thus, using the developed predictive technique may depend on the study circumstances.
Lewis King, SarahJane Cullen, Jean McArdle, Adrian McGoldrick, Jennifer Pugh, Giles Warrington, and Ciara Losty
A large proportion of jockeys report symptoms associated with mental health difficulties (MHDs), yet most do not seek help from professional mental health support services. Due to the paucity of literature in this field, this study sought to explore jockeys’ barriers to, and facilitators of, help-seeking for MHDs. Twelve jockeys participated in semistructured interviews, subsequently analyzed via reflexive thematic analysis. Barriers to help-seeking included the negative perceptions of others (stigma and career implications), cultural norms (masculinity and self-reliance), and low mental health literacy (not knowing where to seek help, minimization of MHDs, negative perceptions of treatment, and recognizing symptoms). Facilitators to help-seeking included education (exposure to psychological support at a younger age), social support (from professionals, jockeys, family, and friends), and media campaigns (high-profile disclosures from jockeys). Findings are consistent with barrier and facilitator studies among general and athletic populations. Applied recommendations and future research considerations are presented throughout the manuscript.
Laura Duval, Lei Zhang, Anne-Sophie Lauzé, Yu Q. Zhu, Dorothy Barthélemy, Numa Dancause, Mindy F. Levin, and Anatol G. Feldman
We tested the hypothesis that the ipsilateral corticospinal system, like the contralateral corticospinal system, controls the threshold muscle length at which wrist muscles and the stretch reflex begin to act during holding tasks. Transcranial magnetic stimulation was applied over the right primary motor cortex in 21 healthy subjects holding a smooth or coarse block between the hands. Regardless of the lifting force, motor evoked potentials in right wrist flexors were larger for the smooth block. This result was explained based on experimental evidence that motor actions are controlled by shifting spatial stretch reflex thresholds. Thus, the ipsilateral corticospinal system is involved in threshold position control by modulating facilitatory influences of hand skin afferents on motoneurons of wrist muscles during bimanual object manipulation.