Saccadic Eye Movement Improves Plantar Sensation and Postural Balance in Elderly Women

Abstract

Vision, proprioception and plantar sensation contribute to the control of postural balance (PB). Reduced plantar sensation alters postural response and is at an increased risk of fall, and eye movements reduce the postural sway. Therefore, the aim of this study was to study the improvement of plantar sensation and PB after saccadic eye movement (SEM) and pursuit eye movement (PEM) in community-dwelling elderly women. Participants (104 females; 75.11 ± 6.25 years) were randomly allocated into the SEM group (n = 52) and PEM groups (n = 52). The SEM group performed eye fixation and SEM for 5 minutes, and the PEM group performed eye fixation and PEM for 5 minutes. The plantar sensation was measured according to the plantar surface area of the feet in contact with the floor surface before and after the intervention. Before and after SEM and PEM with the eyes open and closed, PB was measured as the area (mm 2 ), length (cm), and velocity (cm/s) of the fluctuation of the center of pressure (COP). The plantar sensation of both feet improved in both groups (p < 0.01). Significant decreases in the area, length, and velocity of the COP were observed in the eye open and close in both groups (p < 0.01). The length and velocity of the COP significantly decreased in the SEM group compared to the PEM group (p < 0.05). In conclusion, SEM and PEM are effective interventions for improving plantar sensation and PB in elderly women, with greater PB improvement after SEM.

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

“…All participants were trained to familiarize themselves with the method of performing SEMs prior to the study. SEMs were performed for 3 min, which corresponds to the amount of time required to prevent dizziness or discomfort for the participants [ 8 ], and 5 min of a washout was provided between interventions. Participants were encouraged to walk freely during the washout period.…”

“…Targets were set to appear randomly in horizontal and vertical directions. Fixation of the head of the participants during the intervention ensured that the total visual distance on both the left and right sides was set to be approximately 11° [ 8 , 12 ].…”

“…Lack of visual information in the environment requires re-weighting of other sensory systems, such as the vestibule and proprioception, to control posture [ 4 ]. In addition, previous studies have demonstrated the influence of eye movement on postural control during upright standing [ 5 , 6 , 7 , 8 ]. As such, visual information plays an important role in postural control and the maintenance of postural balance.…”

“…Therefore, to maintain stable upright postural control, attention and external sensory stimulation as well as postural control systems are required. In particular, PS is decreased during SEM rather than during a fixed gaze in young adults [ 7 , 12 ], older adults [ 8 , 13 ], and people with multiple sclerosis [ 14 ]. Such findings indicate that SEM relative to the moving target is used to determine the body position in space [ 11 ], and that it plays an important role in controlling PS during upright standing.…”

“…Therefore, PS is related to plantar sensation [ 19 ]. Moreover, previous studies have shown decreased PS and increased plantar surface area (PSA) of the foot in contact with the ground at a SEM frequency of 0.5 Hz in young adults and older persons [ 8 , 12 , 13 ]. Deterioration of plantar cutaneous sensation information of the foot support on the ground worsens postural balance [ 19 ].…”