Peripheral vision and back tuck somersaults

A temporal quantitative analysis of visuomotor behavior during four twisting somersaults in elite and sub-elite trampolinists

Vision has previously been correlated with performance in acrobatic sports, highlighting visuomotor expertise adaptations. However, we still poorly understand the visuomotor strategies athletes use while executing twisting somersaults, even though this knowledge might be helpful for skill development. Thus, the present study sought to identify the differences in gaze behavior between elite and sub-elite trampolinists during the execution of four acrobatics of increasing difficulty. Seventeen inertial measurement units and a wearable eye-tracker were used to record the body and gaze kinematics of 17 trampolinists (8 elites, 9 sub-elites). Six typical metrics were analyzed using a mixed analysis of variance (ANOVA) with the Expertise as inter-subject and the Acrobatics as intra-subject factors. To complement this analysis, advanced temporal eye-tracking metrics are reported, such as the dwell time on areas of interest, the scan path on the trampoline bed, the temporal evolution of the gaze orientation endpoint (SPGO), and the time spent executing specific neck and eye strategies. A significant main effect of Expertise was only evidenced in one of the typical metrics, where elite athletes exhibited a higher number of fixations compared to sub-elites (p = 0.033). Significant main effects of Acrobatics were observed on all metrics (p < 0.05), revealing that gaze strategies are task-dependent in trampolining. The recordings of eyes and neck movements performed in this study confirmed the use of "spotting" at the beginning and end of the acrobatics. They also revealed a unique sport-specific visual strategy that we termed as self-motion detection. This strategy consists of not moving the eyes during fast head rotations, a strategy mainly used by trampolinists during the twisting phase. This study proposes a detailed exploration of trampolinists' gaze behavior in highly realistic settings and a temporal description of the visuomotor strategies to enhance understanding of perception-action interactions during the execution of twisting somersaults.

Acute Effect of Video Feedback on Self-Regulation and Proprioceptive Control of Standing Back Tuck Somersault in the Absence of Vision

The purpose of this study was to assess the immediate effect of video feedback on the regulation and control of the standing back tuck somersault in the absence of vision. Two groups of male parkour athletes performed the standing back tuck somersault under both open and closed eyes conditions. The first group received video feedback, while the second group received verbal feedback. Concurrent analysis, including kinetic data from a force plate (Kistler Quattro-Jump) and kinematic data in two-dimensional by Kinovea freeware, was employed for motion and technical performance analysis. The results indicate that the loss of vision during the standing back tuck somersault affected only the take-off and ungrouping angle, as well as the vertical velocity and displacement. These effects were consistent regardless of the type of feedback provided (i.e., video feedback or verbal feedback). Furthermore, a significant Vision × Feedback interaction was observed at the level of technical performance. This suggests that the use of video feedback enabled the parkour athletes to maintain a high level of technical performance both with and without vision (i.e., 13.56 vs. 13.00 points, respectively, p > .05 and d = 2.233). However, the verbal feedback group technical performance declined significantly under the no-vision condition compared with the vision condition (13.14 vs. 10.25 points, respectively, with and without vision, p < .001 and d = 2.382). We concluded that when the movement is proprioceptively controlled (i.e., without vision), the video feedback enables the athletes to globally assess the technical deficiencies arising from the lack of vision and to correct them. These findings are discussed based on parkour athletes' ability to evaluate the kinematic parameters of the movement.

Gaze, head and eye movements during somersaults with full twists

Somersaults with or without twists are the most important elements in sports such as gymnastics or trampolining. Moreover, to perform elements with the highest possible difficulty gymnasts should show good form and execution during the flight phase. In order to ensure perfect body control and a safe landing, gaze behavior has been proven to be crucial for athletes to orientate in the air. As eye movement and head movement are closely coordinated, both must be examined while investigating gaze behavior. The aim of the current study is to analyze athletes' head motion and gaze behavior during somersaults with full twists. 15 skilled trampoline gymnasts performed back straight somersaults with a full twist (back full) on the trampoline. Eye movement and head movement were recorded using a portable eye-tracking device and a motion capture suit. The results indicate that gymnasts use the trampoline bed as a fixation point for orientation and control the back full, whereas the fixation onsets for athletes of a better performance class occur significantly later. A strong coordination between gymnasts' eye movement and head movement could be determined: stabilizing the gaze during the fixation period, the eyes move in combination with the head against the twisted somersault direction to counteract the whole body rotation. Although no significant differences could be found between the performance classes with regard to the maximum axial head rotations and maximum head extensions, there seems to be a trend that less skilled gymnasts need orientation as early as possible resulting in greater head rotation angles but a poorer execution.

Gaze behavior of trampoline gymnasts during a back tuck somersault

In trampolining, gymnasts perform a variety of rotational jumping elements and have to demonstrate perfect control of the body during the flying phase. The performance of a somersault should include an opening phase, i.e. the legs are fully extended pointing vertically at 180° called "kick-out". As previous studies have shown, gaze behavior is essential for the controlling during the flight phase and to prepare for a perfect landing. Gymnasts supposedly use the trampoline bed as orientation and differences in gaze behavior can be expected, depending on how a somersault is performed. The present study investigates the gaze behavior of gymnasts during a back tuck somersault on the trampoline. Eleven experienced trampoline gymnasts performed back tuck somersaults with and without a kick-out while wearing a light weight portable eye-tracking device. All subjects fixated their gaze on a specific point at the trampoline bed and thus used visual information to prepare for landing. During the period of fixation, gymnasts' eyes moved continuously downwards to counteract the backwards head movement. The point of fixation differed between each somersault. Apparently, the fixation position depended on the gymnast's landing position in the bed. Performing a somersault with a kick-out allows gymnasts to orient themselves earlier and thus prepare sooner for landing. Unexpectedly, gymnasts of a higher performance class fixated the bed later compared to less experienced athletes. Supposedly, gymnasts of a better class can allow themselves to fixate later in order to optimize the form and execution of a somersault.

Gaze-Shift Patterns during a Jump with Full Turn in Male Gymnasts

When airborne, gymnasts skillfully control their movements to achieve a successful landing. Utilizing visual information from task-specific eye-body coordination patterns (i.e., visual spotting) is thought to be important for gymnasts in the performance of aerial skills. The purpose of this study was to assess the interplay of eye movements and body movements in an aerial skill with a rotation about the longitudinal axis, namely a straight jump with full turn. Participants were 10 skilled male gymnasts (age [ M ±  SD], 23.90 ± 3.28 years) and 14 male nongymnasts (20.57 ± 2.90 years). Gaze behavior during each jump was determined by measuring and integrating eye and head movement data. Results revealed two distinct gaze-shift patterns: a single-step gaze-shift pattern and a multistep gaze-shift pattern. In both patterns, skilled gymnasts stabilized their gaze prior to takeoff and again prior to landing. Whichever pattern was used, gymnasts started to stabilize their gaze on average about 110 milliseconds before landing, which was earlier than nongymnasts. The results suggest that gymnasts use visual information obtained by a particular gaze behavior to generate the necessary amount of rotation and to perform a precise landing in aerial skills involving whole-body rotations.

How do people perceive and generate options?

This chapter examines the question of how people perceive and generate options. Although most current theoretical approaches explain option perception and option generation as requiring extensive and costly cognitive processes, we will argue that people perceive their possibilities for action and generate options without such elaborate means. Borrowing from the contributions of direct perception and bounded rationality, we present and analyze data from three sports tasks: the basketball jump shot, ball allocation in handball, and trampoline somersaulting. Data from kinematics, eye-tracking, and choice behavior experiments are presented and reanalyzed to draw the parallels and distinctions between the two approaches. In conclusion, integrating research on perception, action, and cognition provides a promising description of the bidirectional link between mind and motion.

Effects of visual occlusion and fatigue on motor performance in water

The purpose of this study was to test the effects of visual occlusion and fatigue on the motor performance of vertical skills in synchronized swimming. Experienced synchronized swimmers (n = 12) were randomly assigned to either an exercise or nonexercise (control) activity group. Subjective ratings of fatigue were obtained from the swimmers who then each performed four vertical skills under alternating conditions of vision and visual occlusion before and after either a swimming (designed to induce fatigue) or nonphysical activity. A main effect of activity (p < .03) was found for two measures of performance accuracy (lateral and anterior total distance traveled) but not for lateral and anterior maximum deviation from vertical, indicating that fatigue played a role in executing the skills. The data also indicate that the maintenance of a stationary position is a skill of greater difficulty than maintaining a true vertical. In contrast with previous research findings on synchronized swimmers, a significant effect of vision in all conditions was found, with performance decrements in the conditions of visual occlusion showing that vision provided important sensory input for the swimmers.

Body movements on the men's competition mushroom: a three dimensional analysis of circular swings

OBJECTIVES

To develop a method for the three dimensional analysis of body movements and body positions during the performance of circular swings on the competition mushroom, an apparatus used by young gymnasts for pommel horse training.

METHODS

Five experienced male gymnasts, all of national level, performed three series of 10 circular swings on the competition mushroom. An optoelectronic instrument was used for the detection of the three dimensional movement of 13 body landmarks. From landmark trajectories, several technical measurements were obtained: diameters of ideal circles of ankles, hips, shoulders; deviation of the ankle diameters from circularity and from the horizontal plane; angle between the shoulder, hip, and ankle. The values were used for a quantitative assessment of performance of the five gymnasts.

RESULTS

During the exercise, each ankle should follow a nearly horizontal circular path (deviation from circularity ranged from 3.6% to 6%, deviation from horizontality was 9.4-19.7%), there should be an angle of about 180 degrees at the hips (actual values 146-153 degrees ), and the shoulders should move as little as possible, and only in the lateral plane, without major anteroposterior movements (shoulder movement was 27-31% of ankle movement, hip movement was 16-20%).

CONCLUSIONS

The method could help coaches and gymnasts to determine which parts of the body are not repeating a selected movement with sufficient accuracy and to quantify improvements made after a specific training programme.