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Ocular dominance is an essential visual component of putting. It is important in the alignment phase of the putt, where golfers’ align their ball with the target and in the address phase when they align their club with the ball. It is also important in the putting action phase where it can influence fixation control during the swing and at ball contact. When aligning the ball with the target, golfers tend to use their primary gaze, with their head resting in a natural position. They look directly at the object of interest and they are looking straight ahead. During the putting action phase, when golfers align their club with the ball, they stand in a putting stance and use what has been defined as a putting gaze to look at the ball and the club.

4.5.1 Primary and Putting Gaze Ocular Dominance

The incidence of primary gaze ocular dominance measured in this population of golfers (71% right eye dominance, 26% left eye dominance and 3% no ocular dominance) was similar to what has been previously reported in the general population.92 The distribution of ocular dominance values measured in both primary and putting gazes was not affected by golfers’ skill levels, but ocular dominance in primary gaze was not representative of ocular dominance in putting gaze. In putting gaze the overall strength of golfers’ ocular dominance usually decreased in magnitude and sometimes it disappeared entirely.

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Ocular dominance, while weaker in putting gaze, was fairly well correlated with ocular dominance in primary gaze. This was especially true in the Club Professional group (r=0.867, p=0.012). Although the correlations between the primary and putting gaze ocular dominance were fairly strong overall and in each of the skill groups, the predictability of putting gaze ocular dominance from primary gaze ocular dominance was generally poor. Overall and in the Amateur group, primary gaze ocular dominance measures were only capable of predicting approximately 50% of putting gaze ocular dominance. In the Top Professional group, the predictability of putting gaze ocular dominance from primary gaze ocular dominance was even lower at 37%. The Club Professionals were the only group in which predictability of putting gaze ocular dominance from primary gaze ocular dominance was reasonably high (75%). The high correlation between primary and putting gaze ocular dominance in the Club Professionals was not representative of the entire population. It may have been an artefact of the small sample size of this group (n=7) compared with the other groups (Top Professional=10, Amateur=14), although all three groups were still relatively small.

The effect of stance on ocular dominance has never been previously investigated.102, 104, 105,

108 _{The results of this study show that primary gaze ocular dominance is definitely not a good}

predictor of putting gaze ocular dominance. For this reason it is important that ocular dominance is measured in both primary and putting positions of gaze.

This conclusion is further supported by comparing the magnitude of the change between primary and putting gaze ocular dominances with the magnitudes of the primary and putting gaze ocular dominances. A weak positive correlation existed between the strength of the primary gaze ocular dominance and the magnitude of the change in dominance between primary and putting gazes (Overall, Pearson r=0.612, p<0.001), but no relationship existed between the magnitude of the change in ocular dominance between gazes and putting gaze ocular dominance (Overall, Pearson r=-0.385, p=0.033) even though the correlation was statistically significant. Results in the Top Professional and Amateur skill groups resembled the results in the overall population, but stronger correlations were found in the Club Professional group. Again this was likely an artefact of the small size of the Club Professional group.

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4.5.2 Handedness and Eye-Hand Dominance

The majority of the golfers (89%) in this study reported having a strong right-hand dominance. The distribution of hand dominance did not differ between golfers of different skill levels. With respect to primary gaze eye-hand dominance, 58% of the population had an uncrossed (right eye/right hand or left eye/left hand) dominance, while 35% had a crossed dominance. Unlike Coffey et al.,102 _{the distribution of crossed and uncrossed dominance was}

statistically significantly different between the different skill groups. The Club Professional group had the highest proportion of crossed dominant golfers (80%) and the Amateur group had the highest proportion of uncrossed dominant golfers (77%), but it is unlikely that the dominance differences were related to skill difference, because the Top Professional group had an equal number of golfers with crossed (50%) and uncrossed (50%) dominance.

In putting gaze, 42% of golfers had uncrossed eye-hand dominance and 19% had crossed eye-hand dominance; there was no eye-hand dominance in 39% of golfers. The increase in the number of golfers with no eye-hand dominance in putting gaze was a direct result of the decrease in the magnitude of golfers’ ocular dominance from primary to putting gaze. Crossed eye-hand dominance was more common overall, and in the Amateur group (62%) whereas no eye-hand dominance was more common in Club Professionals (60%). In Top Professionals uncrossed and no eye-hand dominances occurred with equal frequency (Uncrossed 38%, Undefined 38%). Although there appear to be differences in the distribution of eye-hand dominance in putting gaze between the skill groups, the groups were statistically similar.

Ocular dominance and handedness were not correlated with each other in either primary or putting gaze, as expected.80, 94

4.5.3 Conclusion

Ocular dominance can be used to manipulate fixation stability during the swing and at ball contact. If golfers are able to maintain steady fixations through contact, it is highly likely they will be able to maintain a stable and consistent head and body position, which in turn should help improve the biomechanics and the consistency of their swing. The role of ocular dominance in fixation control will be explored later in this thesis, as ocular dominance will be

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included in the multifactorial analysis of golfers’ putting visual strategy [Chapter 6, Vision Strategy in Golf Putting: Training, Competition and Ocular Dominance].

Although handedness may be important in the vision strategy of some individual golfers, it does not appear to be correlated with golfers’ ocular dominance. Eye-hand dominance does not appear to be strongly associated with golfers’ skill levels either, therefore neither factor will be included in the analyses of putting visual strategy conducted in the following chapters.

Measuring golfers’ ocular dominance in both primary and putting gaze is essential for coaches who use ocular dominance information to optimise the putting vision strategy. The proper use of the dominant eye can improve accuracy in aligning both the ball with the target and the club with the ball; if there is no dominant eye, the ball position can be adjusted to induce an ocular dominance and increase precision. Improved alignment should ultimately lead to improved performance if all other factors remain equal.

Relying on primary gaze ocular dominance information to optimise the putting vision strategy, as is currently being done by golf coaches, leads to strategy decisions to be based on incorrect information in 87% of cases. As such, incorporation of the measurement of ocular dominance in putting stance in the assessment of golfers is of fundamental importance.