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Abstract:
Stangl et al. [1] describe differences of vestibulo-ocular reflex (VOR) gain in groups of athletes
accustomed to rotational movements. The authors suggest that the physiological purpose
of these differences is to enable better spatial orientation during whole body rotations. Is the
reverse possible: to use the VOR gain to estimate an individual’s per-rotatory spatial orientation
ability? To answer this question, we looked for differences of the VOR gains in a group
of high-performance gymnasts (gym) versus a group of non-athletes (control). The results
from the gymnasts were also examined for correlations with a rank of their individual perrotatory
spatial orientation (PSO) abilities, performed by their coaches. The subjects’ (gym:
n = 9, age: 10–13 years, control: n = 10, age: 11–12 years) eye movements were recorded
using a video nystagmography system (SMI). They were seated with head fixed in a software
controlled multi-axial whole body rotator. The test included 4 horizontal and 4 vertical sinusoidal
whole body rotations with various frequencies and peak velocities (0.4, 0.2 and 0.1
Hz at 25/s; 0.1 Hz at 50/s). VOR gain was calculated as the ratio of the amplitude of the
best-fit sine wave for the slow-component eye velocity to the amplitude of the stimulus velocity.
The PSO ranking list was based on the independent estimation of three coaches, who
work with the group of gymnasts daily. The results showed clear gain differences between the
4 tests (the higher the speed or frequency, the higher the gains). It was not possible to show
group differences between groups for either horizontal or during vertical rotations. But there
were clear inter-individual differences in both groups, characterized through high significant
individual stability (individual correlations between the tests mostly with p<0.01 [Pearson]).
All the individual coach rankings showed also significant correlations [p<0.05, Spearman]).
The analysis of correlations between vertical gains and PSO showed a clear and significant
correlation (0.4Hz: rS=0.647, p=0.109; 0.2Hz: rS=0.786, p=0.036; 0.1Hz@25/s: rS=0.619,
p=0.102; 0.1Hz@25/s: rS=0.821, p=0.023). Horizontal motion did not show any correlations
with PSO. Differences in VOR gain in subjects accustomed to rotational movements could not
be confirmed. Correlations between the various tests for each subject show they are stable indicators
of VOR response. Correlations between vertical VOR-gains and PSO of the athletes
could indicate a link between VOR parameters and individual per-rotatory multi-axial orientation
abilities.
