The upstart is a fundamental skill in gymnastics, requiring whole body coordination to transfer the gymnast from a swing beneath the bar to a support position above the bar. The aim of this study was to determine the solution space within which a gymnast could successfully perform an upstart. A previous study had shown that the underlying control strategy for the upstart could be accounted for by maximizing the likelihood of success while operating in a noisy environment.1 In the current study, data were collected on a senior gymnast and a computer simulation model of a gymnast and bar was used to determine the solution space for maximizing success while operating in a noisy environment. The effects of timing important actions, gymnast strength, and movement execution noise on the success of the upstart were then systematically determined. The solution space for the senior gymnast was relatively large. Decreasing strength and increasing movement execution noise reduced the size of the solution space. A weaker gymnast would have to use a different technique than that used by the senior gymnast to produce an acceptable success rate.
Michael J. Hiley and Maurice R. Yeadon
Yuko Kuramatsu, Yuji Yamamoto and Shin-Ichi Izumi
into a controllable system ( Bernstein, 1996 ). In particular, individuals with hemiparesis are reportedly heavily reliant on visual inputs ( Marigold & Eng, 2006 ). A whole-body movement task can be constrained by restricting the vision of poststroke individuals with hemiparesis, who then have to
Melanna F. Cox, Greg J. Petrucci Jr., Robert T. Marcotte, Brittany R. Masteller, John Staudenmayer, Patty S. Freedson and John R. Sirard
main outcomes. For this focal sampling protocol, a new event is recorded each time a participant changes a component of their movement for at least one second. The main outcomes included whole-body movement, locomotion, activity type and the metabolic equivalent (MET) value for the whole-body movement
Bradley Fawver, Garrett F. Beatty, Kelly M. Naugle, Chris J. Hass and Christopher M. Janelle
Emotional states influence whole-body movements during quiet standing, gait initiation, and steady state gait. A notable gap exists, however, in understanding how emotions affect postural changes during the period preceding the execution of planned whole-body movements. The impact of emotion-induced postural reactions on forthcoming posturomotor movements remains unknown. We sought to determine the influence of emotional reactions on center of pressure (COP) displacement before the initiation of forward gait. Participants (N = 23, 14 females) stood on a force plate and initiated forward gait at the offset of an emotional image (representing five discrete categories: attack, sad faces, erotica, happy faces, and neutral objects). COP displacement in the anteroposterior direction was quantified for a 2 second period during image presentation. Following picture onset, participants produced a posterior postural response to all image types. The greatest posterior displacement was occasioned in response to attack or threat stimuli compared with happy faces and erotica images. Results suggest the impact of emotional states on gait behavior begins during the motor planning period before the preparatory phase of gait initiation, and manifests in center of pressure displacement alterations.
Akito Miura, Kazutoshi Kudo, Tatsuyuki Ohtsuki, Hiroaki Kanehisa and Kimitaka Nakazawa
In this study, we investigated muscle cocontraction during a street dance movement task to provide evidence that the level of muscle cocontraction is associated with degree of proficiency in whole-body sensorimotor synchronization movement. Skilled street dancers and nondancers were required to synchronize a knee-bending movement in a standing position to a metronome beat. The dancer group showed significantly smaller variability of temporal deviation (defined as the peak kneeflexion time minus beat onset time), and lower level of muscle cocontraction analyzed by electromyographic data of the agonist and antagonist muscles of the upper and lower leg than did the nondancer group. In addition, multiple regression analyses revealed that the group effect significantly predicted the level of muscle cocontraction. These results show that the level of muscle cocontraction in the lower limbs during whole-body sensorimotor synchronization movement is associated with the degree of proficiency of the movement.
Cheng-Feng Lin, Wan-Chin Lee, Yi-An Chen and Bih-Jen Hsue
Fatigue in ballet dancers may lead to injury, particularly in the lower extremities. However, few studies have investigated the effects of fatigue on ballet dancers’ performance and movement patterns. Thus, the current study examines the effect of fatigue on the balance, movement pattern, and muscle activities of the lower extremities in ballet dancers. Twenty healthy, female ballet dancers performed releve on demi-pointe before and after fatigue. The trajectory of the whole body movement and the muscle activities of the major lower extremity muscles were recorded continuously during task performance. The results show that fatigue increases the medial-lateral center of mass (COM) displacement and hip and trunk motion, but decreases the COM velocity and ankle motion. Moreover, fatigue reduces the activities of the hamstrings and tibialis anterior, but increases that of the soleus. Finally, greater proximal hip and trunk motions are applied to compensate for the effects of fatigue, leading to a greater COM movement. Overall, the present findings show that fatigue results in impaired movement control and may therefore increase the risk of dance injury.
* Songning Zhang * Max R. Paquette * Clare E. Milner * Elizabeth Brock * 8 2014 30 4 501 507 10.1123/jab.2013-0039 Determining the Solution Space for a Coordinated Whole Body Movement in a Noisy Environment: Application to the Upstart in Gymnastics Michael J. Hiley * Maurice R. Yeadon * 8 2014 30
Paul G. Montgomery and Brendan D. Maloney
.5 m·s −1 ), and accumulated jumps (>40 cm). Whole-body movement demands of 3×3 basketball were calculated using the PlayerLoad ™ function. Briefly, PlayerLoad is a previously validated 11 , 12 measurement of external physical loading that can be defined as the instantaneous rate of change of
David M. Werner and Joaquin A. Barrios
Core stability is considered fundamental for optimized whole-body movement. Functionally, core stability is partly reflected in the ability of the trunk to maintain or return the body to equilibrium when challenged by both expected and unexpected internal and external perturbations. 1 , 2 While no
Marni J. Simpson, David G. Jenkins, Aaron T. Scanlan and Vincent G. Kelly
change in movement velocity, respectively, in a horizontal or anterior–posterior direction. The direction for ACCEL was −45° to 45°, and for DECEL, it was −135° to 135°. A COD was defined as a rapid, whole-body movement with a sudden change of velocity and direction of −135° to −45° (left) and 45° to 135