Sensory function Visual cues Sample Clauses

Sensory function Visual cues. Visual cues provide information regarding the position and motion of the head with respect to surrounding objects, and a reference for verticality (Dichgans et al., 1973). Visual cues are not totally necessary to control static balance such as sitting quietly or sitting and traveling by bus (e.g., exposure to a moving visual scene) (Xxxxxxxxx and Xxxxxxxx, 1997). Although, the latter is only partially true. Xxxxxxx and colleagues (2001) demonstrated that the postural response to a moving visual scene is attenuated when humans are given precise information about when and how the scene will move in the immediate future. When such precise information is given, the brain uses it to interpret the source of visual motion. The speed of visual motion on its turn, influences the magnitude of the evoked postural response with faster speeds being correlated with lower response gains (Xxxxxxx and Xxxxxxxx, 1995; Xxxxxxx et al. 2005; Day et al., 2016). Further, visual cues actively contribute to postural control during quite stance (Xxxxxxx, 1946; Xxxxxxx et al., 1982; Xxx et al., 2016), consequently, a person’s sway amplitude often increases when they have their eyes closed compared to eyes open. Also, when somatosensory input is disrupted such as when the support surface is unstable or due to a medical condition such as peripheral neuropathy, the visual input becomes essential for less postural sway (Xxxxxxx et al., 1982). However, in healthy young adults, a recent study (Xxxxxxxx et al., 2019) demonstrated that although, postural sway was increased after induction of ankle muscle fatigue, and saccadic eye movements consistently reduced postural sway in fatigued and unfatigued ankle muscle conditions, interestingly, closing the eyes increased adults’ sway when their ankle muscles were not fatigued but reduced their sway when the ankle muscle were fatigued. Lastly but most importantly, visual input significantly contributes to postural control when a person takes a step or reaches to grasp to recover their postural stability (Xxxx et al., 2003). For example, when an object is about to be lifted from the ground or reached from a top shelf the visual input determines the characteristics of postural adjustments anticipated and needed to stabilise the body before and during lifting the object. However, when someone is pulled or pushed unexpectedly in environments that are more visually active such as standing on public transport or being accidently pushed by another perso...