Article

Proprioceptive input from the neck is important for maintenance of upright
standing. Although neck musculature fatigue has been demonstrated to impair
standing balance, there is limited understanding of the underlying postural
mechanisms. This study aimed to further examine the effects of neck musculature
fatigue on standing by using modern analysis of center of pressure (CoP) data.
Forty-eight young healthy adults stood quietly on a balance board for 1 min
before and after performing repeated weight-resisted scapular elevation
exercises. In a supplementary study on 20 participants, we examined (i) the
effects of visual deprivation and (ii) the test-retest reliability of the
traditional and wavelet-based CoP measures. Test-retest reliability of the CoP
measures was moderate to good (intraclass correlation coefficients ranged from
0.58 to 0.94). With neck muscle fatigue or without vision, traditional measures
of CoP velocity and standard deviation increased monotonically. Wavelet analysis
revealed that CoP velocity within the ultralow (<0.10 Hz) and moderate (1.56-6.25
Hz) frequency bands increased post-fatigue. Without vision, CoP velocity
increased in all but the ultralow frequency band. Our data suggest that
post-fatigue, vision may be the main compensatory postural mechanism for altered
neck proprioception. In conclusion, our findings reveal more nuances than the
simple assertion that neck musculature fatigue increased postural sway and they
advocate the use of wavelet analysis in examining postural mechanisms associated
with neck proprioception.
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Langue : ANGLAIS