I. Kita et al., CARDIORESPIRATORY CHANGES WHEN BALANCING ONES WHOLE-BODY ON ONE LEG WITH EYES CLOSED, Japanese Journal of Physiology, 46(2), 1996, pp. 145-153
Postural control system has been extensively studied in terms of somat
ic motor function, but little is known about its connection with human
autonomic function. The purpose of this study was to determine the ca
rdiorespiratory changes in response to the 3-min load that was perform
ed by balancing one's whole body on one leg with eyes closed (SOLEC lo
ad) or eyes open (SOLEO load) in 11 healthy young subjects (5 males an
d 6 females, mean age 20.8+/-1.9 year). Blood pressure (BP), heart rat
e (HR), respiratory rate (RR), inspiratory and expiratory duration (T-
i and T-e), tidal volume (VT), and oxygen uptake (V-O2) were measured
before, during, and after the load. The SOLEC load produced significan
t increases in HR and systolic BP within 1 min. There were further inc
reases in systolic and diastolic BP during the late period of the load
. Metabolic rate (V-O2) showed a gradual increase during the SOLEC loa
d, indicating that the late responses would be partly due to metabolic
alteration, The early responses are considered to be mediated neurall
y through the postural control system which receives the afferent inpu
ts arising from vestibular system and from muscle proprioceptors of th
e leg. In contrast, SOLEO load caused small insignificant changes in B
P, HR, VT, and V-O2 suggesting that a visual input is essential for ba
lancing a postural change. The balance test with eyes closed may have
value in a clinical neurological rehabilitation setting.