Relationship between Initiation of Gaze Stabilisation and Angle of

Head and Trunk Movement during a Jump with Full Turn

Yusuke Sato

, Shuko Torii

and Masaharu Sasaki

College of Commerce, Nihon University, Tokyo, Japan

College of Arts and Sciences, University of Tokyo, Tokyo, Japan

Faculty of Liberal Arts, Hirosaki Gakuin University, Aomori, Japan

Keywords: Eye Movement, Gaze Behaviour, Gymnastics, Landing, Spatial Orientation.

Abstract: Over time it has become clear that there is a relationship between visual spotting and movement in the air in

gymnasts, but that relationship during basic skills that are simple for skilled gymnasts, such as a jump with

full turn, is still unclear. The aim of this study was to reveal the relationship between the initiation of gaze

stabilisation and the magnitude of body rotation angle during landing. The participants were 10 skilled male

gymnasts. Their eye movements during jumps were measured using electrooculography and their body

movements were recorded using two high-speed digital cameras. The initiation of gaze stabilisation

immediately before landing was determined by combining eye and head movement data. We found various

relationships between initiation of gaze stabilisation and jump movement in gymnasts, such as a positive

correlation between the gaze stabilisation and the head-on-trunk angle at the initiation of gaze stabilisation

and angles of trunk rotation at the landing. The results suggest that gymnasts who can look at locations quicker

before landing might have an advantage in completing rotation, as well as gaining enough time to use visual

information. For achieving early gaze stabilisation, it may be necessary to rotate the head ahead of the trunk.

1 INTRODUCTION

Gymnasts perform in a fixed environment in which

they use visual, vestibular, and somatosensory

information to execute their routine (Sands, 1991). In

particular, visual information is important for

gymnasts to control their landings with precision (Lee

et al., 1992), even when performing basic elements,

such as a jump with full turn (Figure 1) (Rezette and

Amblard, 1985).

The jump with full turn requires a rotation of 360

deg about the longitudinal body axis during a straight

jump. Gymnasts stabilise their gaze immediately

before landing (Sato et al., 2015). Gaze stabilization,

so-called “spotting” (Davlin et al., 2004; Laws et al.,

2002) during landing is especially important for

control of landing (Berthoz and Pozzo, 1994) and the

magnitude of rotation (Heinen et al., 2012a).

Interestingly, there is a possibility that spotting

not only enables movement control using visual

information obtained through gaze stabilisation, but

also directly affects a performer’s movement (Heinen

et al., 2012; Heinen and Vollmer, 2014). For example,

manipulating the fixation point during the takeoff

phase in a back tuck somersault influences the

duration of the flight phase (Heinen and Vollmer,

2014). Heinen et al., (2012b) also reported that there

is a relationship between visual spotting and

movement when performing high bar dismounts; for

example, fixations during the preparatory giant

swings are correlated with flight distance during

dismount. There is an interplay of eye-head

movements with gaze displacement and body

movements even while executing whole-body

rotation without a jump

Figure 1: Jump with full turn (360°).

(Hollands et al., 2004). Therefore, it was

hypothesised that gaze stabilisation immediately

before landing during a jump with full turn correlates

the body movements. The aim of this study was to

reveal the relationship between the initiation of gaze

Sato, Y., Torii, S. and Sasaki, M..

Relationship between Initiation of Gaze Stabilisation and Angle of Head and Trunk Movement during a Jump with Full Turn.

In Proceedings of the 3rd International Congress on Sport Sciences Research and Technology Support (icSPORTS 2015), pages 165-168

ISBN: 978-989-758-159-5

165

stabilisation and the magnitude of body rotation angle

during landing.

Clarifying this problem may contribute to

developing a more effective training programme.

When gymnasts perform aerial movements with

longitudinal axes, a lack of rotation at landing leads

to deductions of score in competitive gymnastics

(Fédération Internationale de Gymnastique, 2013). If

gymnasts can quickly stabilise their gazes, it has a

positive effect on controlling the magnitude of

rotation, an advantage of early gaze stabilisation that

may be suggested in addition to those of previous

studies.

2 METHODS

2.1 Participants

The participants were 10 skilled male gymnasts. After

receiving a written explanation of the aim and content

of the experiment, all participants provided written

informed consent.

2.2 Apparatus and Procedure

The participants performed a jump with full turn in a

gymnasium. A soft mat was put on a floor to ensure

safety. Participants wore comfortable clothes such as

sportswear and were barefoot for all tasks. Before the

experimental trial, markers were attached to the

auricles and acromia of each participant in order to

easily determine head and trunk movements in space.

The experimental task was a jump with full turn.

Participants jumped vertically and rotated 360 deg

about the longitudinal body axis. They stood upright

in the centre of the safety mat and then jumped and

were free to select the direction of rotation. We

instructed the participants to look forward at the

beginning of each trial, and to make a perfect landing.

They were allowed to practice freely before the

experiment and then were prepared for the

experiment. Each participant performed a jump with

full turn three times. The experimenter monitored eye

movement data during the jump, and if the data were

noisy, the gymnasts performed the jump again.

Landing performance was estimated in conformity to

the international competition rules for men’s artistic

gymnastics (Fédération Internationale de

Gymnastique, 2013).

In order to estimate gaze, horizontal eye

movement and head movement were measured. Eye

movement during the jump was clarified by

electrooculography (EOG) using a wireless system

(500 Hz; BioLog DL-4000; S&ME, Tokyo, Japan).

An electrode was attached to the outer canthus of each

eye. Simultaneously, to determine horizontal head

and trunk movement, the experimental trials were

recorded using two high-speed digital cameras

(240f/s, EX-F, Casio, Tokyo, Japan). The cameras

were placed at positions diagonally in front of the

mat.

2.3 Data Acquisition and Analysis

The angle of eye movement was calculated by

calibrating EOG. The recorded movement data were

downloaded to a computer, and measurement points

were digitised using motion analysis software

(Frame-DIASIV, DKH Inc., Tokyo, Japan). The

three-dimensional coordinates of the head and trunk

points were obtained by direct linear transformation

(DLT). The angle of horizontal head movement was

obtained from the line connecting the auricles. The

angle of horizontal trunk movement was obtained

using the line connecting the acromia. The head and

trunk data were filtered using a Butterworth low-pass

filter with a 6-Hz cutoff.

The optical signal was recorded by the cameras,

adding in the PC to synchronise the kinematics and

eye movement data. To synchronise, we use the body

movement data as a basis and picked eye movement

data to synchronise with head data.

Gaze during the jumps was determined by

combining eye and head movement data

(Anastasopoulos et al., 2009). Head-on-trunk

movement was obtained from the angle between the

head and trunk segments. The initiation time of gaze

stabilisation before landing was defined as the point

in time of the completion of gaze shifting in the

rotational direction, and was calculated on the basis

of landing. Landing was defined as the time when the

participant’s foot visibly made contact with the

ground.

Variables pertaining to the performance of each

participant were used for statistical analysis. This

analysis was performed using SPSS 18.0 for

Windows (IBM, Tokyo, Japan). The Pearson

correlation coefficients between head/trunk/head-on-

trunk angles at the time of initiation of gaze

stabilisation and head/trunk angles at the landing and

initiation time of gaze stabilisation were used to

evaluate the relationship between gaze behaviour and

movement kinematics in gymnasts. The level of

significance was set at p < .05.

icSPORTS 2015 - International Congress on Sport Sciences Research and Technology Support

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3 RESULTS

All gymnasts performed perfect landings. Their eyes

rotated in the direction opposite to that of their head

movement before landing. Almost at the same time,

their gazes started to stabilise. The angles of head and

trunk movement were almost 0 deg at the beginning

of the trial, and after the rotation, the angles had

reached approximately 360 deg.

The mean angle of head movement at the

initiation of gaze stabilisation was 299.71 ± 8.47 deg;

the mean angle of trunk movement at the initiation of

gaze stabilisation was 263.64 ± 22.57 deg; the mean

angle of head-on-trunk at the initiation of gaze

stabilisation was 35.40 ± 19.19 deg; the mean angle

of head movement at the landing was 316.15 ± 17.12

deg, and the mean angle of trunk movement at the

landing was 306.07 ± 18.05 deg. Therefore, head

movement preceded trunk movement at the initiation

of gaze stabilisation.

Figure 2: Example of gaze and head/trunk/head-on-trunk

movements during a jump with full turn.

The analysis revealed certain relationships between

the initiation of gaze stabilisation and the jump

movement in gymnasts. Table 1 shows the correlation

coefficients. According to these results, the initiation

time of gaze stabilisation is negatively correlated with

the head/trunk angle at the initiation of gaze

stabilisation and positively correlated with the head-

on-trunk angle at the initiation of gaze stabilisation,

head angle and trunk angle at landing. Therefore,

when gymnasts execute quick gaze stabilisation

before landing, the angle of head and trunk movement

is smaller at that time and larger at landing.

4 DISCUSSION

The aim of this study was to reveal the relationship

between initiation of gaze stabilisation and movement

kinematics before landing. Although gymnasts use

visual information to land completely during a jump

with turn (Rezette and Amblard, 1985) through gaze

stabilisation (Sato et al., 2014), the relationship

between gaze stabilisation before landing and

magnitude of rotation was unclear. Clarifying this

problem may contribute to developing a more

effective training program.

The gymnasts’ initiation of gaze stabilisation

correlated with all the kinematic variables in this

study. A functional relationship between gaze

behaviour and movement has been reported in recent

years (Heinen et al., 2012b; von Lassberg et al.,

2014). This study’s results also showed that gaze

behaviour is linked to magnitude of body rotation

angle. The gaze stabilisation that occurs before

landing is thought to lead to optimal landing and

precise rotation (Heinen et al., 2012a; Hondzinski and

Darling, 2001). Early gaze stabilisation before

landing probably provides a time margin in which to

use the visual information and control landing.

Accordingly, to reveal how gymnasts look at

locations quickly would be an interesting research

project. From this point of view, it would be

important to note that there is a relationship between

initiation time of gaze stabilisation and head-on-trunk

angle. For achieving early gaze stabilisation, it may

be necessary to rotate the head ahead of the trunk.

Interestingly, the gymnasts who started to stabilise

their gazes earliest before landing rotated their bodies

more. A lack of rotation leads to deductions in

gymnastics (Fédération Internationale de

Gymnastique, 2013). Therefore gymnasts who can

look at locations quicker before landing might have

an advantage in completing rotation, as well as

gaining enough time to use visual information.

Table 1: Correlation coefficients between gaze parameters

and rotational angle in gymnasts.

Variable

Initiation of gaze

stabilization

Landing

Head Trunk

Head-on-

trunk

Head Trunk

Gaze

stabilisation

-.73*

-.92** .77** .75* .81**

Note. Gaze stabilisation = Initiation of gaze stabilisation

**: p < .01. *: p < .05.

-50

150

250

350

-50

150

250

350

-50

150

250

350

0.25 s

-50

Takeoff Landing

Head

Gaze

Trunk

Head-on-trunk

Initiation of

gaze stabilization

Angle of rotation (deg)

Relationship between Initiation of Gaze Stabilisation and Angle of Head and Trunk Movement during a Jump with Full Turn

167

We found that initiation time of gaze stabilisation

correlates with magnitude of rotation. However, the

present study cannot identify a way for gymnasts to

look more quickly at locations before landing, the

main factor of the quick look. From this viewpoint, it

would be very useful for a future study to explore how

gymnasts quickly start to stabilise their gaze before

landing.

There is a relationship between gaze behaviour

and body movements during the jump with full turn,

but the relationship between eye-body interactions

and expertise is unclear. Future studies are necessary

to determine the influence of expertise on eye-body

interactions by comparing between experts and

novices (Heinen, 2011).

5 CONCLUSIONS

The aim of this study was to reveal the relationship

between initiation of gaze stabilisation and movement

kinematics before landing. We found various

relationships between initiation of gaze stabilisation

and the jump movement in gymnasts; for example,

positive correlation between gaze stabilisation and

angle of trunk rotation at landing. The results suggest

that gymnasts who can look at locations quicker

before landing might have an advantage in

completing rotation, as well as using visual

information to control landing. For achieving early

gaze stabilisation, it may be necessary to rotate the

head ahead of the trunk. It is hoped that the findings

obtained by the present study will contribute to the

development of new training materials and methods.

ACKNOWLEDGEMENTS

This research was supported by JSPS KAKENHI

Grant-in-Aid for Young Scientists (B), Grant Number

26750280.

REFERENCES

Anastasopoulos, D., Ziavra, N., Hollands, M., & Bronstein,

A. (2009). Gaze displacement and inter-segmental

coordination during large whole body voluntary

rotations. Experimental Brain Research, 193(3), 323-

336.

Berthoz, A., & Pozzo, T. (1994). Head and body

coordination during locomotion and complex

movements. In S.P. Swinnen, J. Massion, & H. Herer

(Eds.), Interlimb coordination: Neural, dynamical, and

cognitive constraints (pp. 147-165). San Diego:

Academic Press.

Davlin, C. D., Sands, W. A., & Shultz, B. B. (2004). Do

gymnasts" spot" during a back tuck somersault.

International Sports Journal, 8(2), 72-79.

Fédération Internationale de Gymnastique. (2013). 2013-

2016 Code of Points: Men’s Artistic Gymnastics.

Retrieved from http://www.fig-

gymnastics.com/site/rules/disciplines/art.

Heinen, T., Velentzas, K., & Vinken, P. M. (2012a).

Analyzing gaze behavior in complex (aerial) skills.

International Journal of Sport Science and

Engineering, 6(3), 165-174.

Heinen, T., Velentzas, K., & Vinken, P. M. (2012b).

Functional relationships between gaze behavior and

movement kinematics when performing high bar

dismounts–an exploratory study. Human Movement,

13(3), 218-224.

Hollands, M. A., Ziavra, N. V., & Bronstein, A. M. (2004).

A new paradigm to investigate the roles of head and eye

movements in the coordination of whole-body

movements. Experimental brain research, 154(2), 261-

266.

Hondzinski, J. M., & Darling, W. G. (2001). Aerial

somersault performance under three visual conditions.

Motor Control, 5(3), 281-300.

Laws, K., Sugano, A., & Swope, M. (2002). Pirouettes.

Physics and the art of dance: Understanding movement

(pp. 63-85). New York: Oxford University Press.

Lee, D. N., Young, D. S., & Rewt, D. (1992). How do

somersaulters land on their feet? Journal of

Experimental Psychology: Human Perception and

Performance, 18(4), 1195 -1202.

Rezette, D., & Amblard, B. (1985). Orientation versus

motion visual cues to control sensorimotor skills in

some acrobatic leaps. Human Movement Science, 4(4),

297-306.

Sato, Y., Torii, S., Sasaki, M., & Heinen T. (2015). Gaze

Shift Patterns during a Jump with Full Turn in

Gymnasts. Manuscript in preparation.

Sands, W. A. (1991). Spatial orientation while

somersaulting. Technique, 11(1), 16-19.

von Lassberg, C., Beykirch, K. A., Mohler, B. J., &

Bülthoff, H. H. (2014). Intersegmental Eye-Head-Body

Interactions during Complex Whole Body Movements.

PloS one, 9(4), e95450.

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