Validity and reliability of a Chinese rating of perceived exertion scale in young Mandarin speaking adults

Patellofemoral Pain, Q-Angle, and Performance in Female Chinese Collegiate Soccer Players

Background and objective: Female sports injuries have been neglected by science, and few relevant studies have considered female subjects. Knee pain in female soccer players is more common than in male soccer players. The number of days of absence from training and competition has been shown to be higher in females than males. The reporting of knee pain is common in female soccer players, but whether knee pain is associated with morphological features is unclear. The Q-angle of the knee has been hypothesized to be a causal factor in knee pain. Asian females have shown higher levels of valgus than non-sporting Caucasian populations, but no data exist for female Chinese players. The aim of our study was to investigate whether there are associations between knee pain, the Q-angle of the lower limb, jump performance, play time, and perceived exertion in female Chinese collegiate soccer players. Materials and Methods: We measured the Q-angle, patellofemoral/anterior knee pain (SNAPPS questionnaire), and CMJ and SJ performance of 21 subjects (age: 20.09 ± 1.13 years, weight: 56.9 ± 6.26 kg, height: 164.24 ± 4.48 cm, and >10 years of practice) before and after a match; Borg scale and play time results were also recorded. Results: We found that our studied group had higher Q-angles in comparison to other ethnic groups reported in the literature, as well as an association of the Q-angle with the age, height, and weight of the players; however, contrary to other studies, we did not find any association between the Q-angle and knee pain, jumps, play time, or perceived exertion. Knee pain was not associated with any of the measured variables. Conclusions: Female Chinese soccer players showed higher Q-angles than players of other ethnic groups, a result that was associated with anthropometrics. The Q-angle was not found to be associated with knee pain, for which the sole determinant was body height.

A facile inverse dynamics method to study the impacts of fatigue on the lower limb biomechanics

Fatigue can significantly affect the biomechanics of the anterior cruciate ligament (ACL) during single-legged jumping, and these changes are closely related to ACL injuries. Unfortunately, there is no convenient way to accurately and quickly track these changes. This present study aimed to develop such a method based on video capture and inverse dynamics simulation.Are our method's results accurate and reliable? Fifteen participants performed sing-legged jumping before and after the fatigue protocol, and their actions were videotaped. The videos were processed and converted to marked motion data, used to drive the mannequin model in AnyBody Modelling System (AMS) for the inverse dynamics simulations. The ACL segment was also constructed based on one participant's MRI data and added the mannequin model.Our results were similar to the findings from previous studies. Neuromuscular fatigue decreased the peak flexion angles and increased the low-the-limb muscle strength and activation. These alterations might contribute to ACL tears and ruptures. In addition, the simulation showed that the ACL force significantly (p < 0.05) increased as a result of fatigue during single-legged jumping. Our study provides a facile and reliable method to study the effects of neuromuscular fatigue on lower-the-limb biomechanics. Such a method can be applied to investigate other risk factors on ACL injuries and assist in developing workable plans for athlete training in the future.

Does acute exercise benefit emotion regulation? Electrophysiological evidence from affective ratings and implicit emotional effects on cognition

Negative affect impacts cognition, and sometimes may interfere with cognitive function. Furthermore, emotion regulation is thought to play an important role in easing the suffering from negative affect. However, whether acute exercise could ease the emotional interference caused by unconscious affect on cognitive control, remains to be investigated. To test this, we used behavioral measures combined with event-related potentials (ERPs) to specifically investigate (i) the impacts of negative affect evoked by implicit cues on conflict inhibition (Flanker task), and (ii) whether acute exercise could mitigate these effects. Furthermore, we examined (iii) the impact of acute exercise on frontal alpha asymmetry as an index of cognitive emotional down-regulation to emotional stressors. Forty young women (age range from 18 to 26) were randomly assigned to either a control group (n = 20) or an exercise group (n = 20), and a repeated-measures design with a space of one week between measures was conducted. Results demonstrated that negative Flanker trials produced larger N1 amplitude but smaller N200 amplitude than neutral trials; furthermore, acute exercise could mitigate emotional effects on N1. However, significant effects of acute exercise on the resting and responding frontal alpha asymmetry were not found. The distinct direction of the impacts of negative affect on cognition are discussed together with implications about the effects of attention allocation on exercise-enhanced emotion regulation.