Comparison of Postural Sway, Plantar Cutaneous Sensation According to Saccadic Eye Movement Frequency in Young Adults

Abstract

The crossover trial study aimed to identify the saccadic eye movement (SEM) frequency to improve postural sway (PS) and plantar cutaneous sensation (PUS) in young adults. The 17 participants randomly performed 0.5-, 2-, and 3-Hz SEM. The SEM frequency was determined to allow the target to appear once per 2 s (0.5 Hz), twice per second (2 Hz), or thrice per second (3 Hz). SEM performance time was 3 min with a washout period of 5 min. PS and PUS were measured at baseline and during 0.5-Hz, 2-Hz, and 3-Hz SEMs using a Zebris FDM 1.5 force plate. PS was determined by measuring the sway area, path length, and speed of center of pressure (COP) displacement, and PUS was determined via the plantar surface area (PSA). In PS parameters, there was a significant difference among the SEM frequencies in the COPsway area PSAleft foot and PSAright foot. Compared to that at baseline, COPsway area decreased at 0.5 Hz and 2 Hz, while PSAleft foot and PSAright foot increased at 2 Hz. These results suggest that 2 Hz SEM may improve PS and PSA.

Fast Saccadic Eye Movements Contribute to the Worsened Postural Sway in Older Adults Who Have Experienced Falls

“…Targets were randomly displayed across the screen in diagonal, vertical, and horizontal directions. In this study, SEM rates of 0.5, 2 and 3 Hz were used, and targets appeared once per 2 s, twice per 1 s, or 3 times per 1 s at 0.5, 2 and 3 Hz, respectively [ 8 , 13 ].…”

“…CoP displacement plays a very important role in confirming postural control and PS [ 7 ]. Previous studies have reported decreased sway area, length, and average velocity of the center of pressure (CoP) during saccadic eye movement (SEM) both in young adults [ 8 ] and in older adults [ 9 , 10 ]. As such, a fast gaze-moving SEM that visually tracks a moving target from one point to another can reduce PS.…”

“…Despite significant research on SEM, no study has been able to identify differences in balance ability between fallers and non-fallers following SEM stimulation. In addition, SEM speed decreases with age [ 12 ], and participants may complain of dizziness when performing SEM speeds above 3 Hz [ 8 ]. Therefore, this study aimed to examine the changes in PS and differences between groups at 0.5, 2 and 3 Hz SEM stimulation.…”

Decreased Saccadic Eye Movement Speed Correlates with Dynamic Balance in Older Adults

“…The red dot appeared in one place on the screen, disappeared, and immediately reappeared in another position, which caused the participants' eyes to follow the red dot, which appeared randomly in the horizontal and vertical directions. The moving speed of the red dots on the monitor was set to 0.5, 2, and 3 Hz for 50 s, as described in a previous study [9]. The frequency was 0.5 Hz if the target appeared once every 2 s, 2 Hz if it appeared twice per second, and 3 Hz if it appeared thrice per second.…”

“…SEM is a rapid eye movement that changes the fixation point of the gaze; its preparation and performance are determined by the coordinated operation of many brain structures, including brainstem structures and different areas of the cerebral cortex [7]. SEM relative to the moving target plays an important role in controlling balance during upright standing body position in space [8,9]. These findings indicate that SEM may be correlated with balance ability.…”