Could hand-eye laterality profiles affect sport performance? A systematic review.

BACKGROUND: Laterality effects on sports performance have been a field of interest for the sports sciences, especially in asymmetrical sports, which require the preferential use of one side of the body. Some sports in particular involve the visual system and ocular laterality, due to the need to clearly focus on a dynamic object (ball, opponent, projectile, etc. ). The relationship between manual and ocular laterality results in two perceptual-motor profiles, one where the dominant hand and eye are ipsilateral (uncrossed hand-eye laterality profile, UC-HELP), and the other where they are contralateral (crossed hand-eye laterality profile, C-HELP).

METHODOLOGY: A systematic review of the literature was carried out to determine the prevalence of hand-eye laterality profiles in the different sports modalities and their relationship with psychological factors and sports performance. Searches of PsycInfo, Medline, Scopus and grey literature identified 14 studies (2,759 participants) regarding hand-eye laterality in sports that met the eligibility criteria.

RESULTS: Previous studies have estimated that between 10-30% of the general population exhibit a C-HELP, and 70-90% have an UC-HELP. The results of the reviewed studies indicate that in some sports the percentage of C-HELP is higher in regular and high-level athletes than in the normal population: golf (52.55%), soccer (53%), tennis (42%) and team sports (50.7%). In target sports (archery and shooting) athletes with an UC-HELP seem to have an advantage given the significant concentration of this profile in the highest performing populations (82.3%). In basketball, cricket and golf, the literature reviewed also reported biomechanical differences in the execution of some techniques between the two profiles. We did not find any study in our review that related hand-eye laterality with cognitive, tactical, or psychological aspects of athletes.

CONCLUSIONS: These results should be taken with great caution due to the potential bias linked to the methodologies used in the investigations, the heterogeneity in the assessment of hand-eye laterality, the few studies available on the subject and the indirect nature of many of the observed relationships between performance and laterality. For further investigation, we propose a standardized terminology and protocol of hand-eye laterality assessment in sports. The advancement in knowledge about hand-eye laterality profiles, along with the study of the relationship with psychological or tactical-sports patterns, can contribute to more effective development plans for athletes and can be a complement to talent detection.