Investigation of body weight distribution and ocular convergence in children practising table tennis

Introduction
Table tennis can be classified as a low-injury sport; however, it is associated with the frequent adoption of a forced playing position. Players are at significant risk of developing lateral spinal curvatures and asymmetries. A review of the scientific literature showed a variety of findings on the relationship between temporomandibular joints and posture.

Aims: This study aimed to investigate the relationship between temporomandibular joint (TMJ) dysfunction, lower limb loading and ocular convergence in table tennis players between 8 and 15 years old.

Material and methods
The study material consisted of the results obtained from 45 children between 8 and 15 years old. Players attending table tennis sports clubs were included in the study. The research group consisted of 18 girls (40%) and 27 boys (60%). A two-weights test was used to assess lower limb loading. In addition, visual system abnormalities were examined by measuring the near point of convergence. Two trials were used for each athlete before and after transient repositioning of the temporomandibular joints.

Results
Statistical analysis showed a significant association between temporomandibular joint position change and ocular convergence. There was no statistically significant association between lower limb loading and change in TMJ position. The relationship between lower limb loading and ocular convergence, athlete's training seniority, and received orthodontic treatment was also not supported.

Conclusions
A transient repositioning of the TMJ affected the trial of ocular convergence in the studied group. There was no correlation between TMJ changes and other measured parameters among examined tennis players.