Postural control: toe-standing versus heel-toe standing.
Toe-standing is observed in a number of populations who are able to stand without loss of balance and also those who have balance problems. Intuitively, individuals who stand on their toes are able to successfully regulate their whole body movement in order to keep themselves stable. Force platform data were collected for ten able-bodied subjects during three quiet standing postures, (a) heel-toe standing; (b) half-toe standing and (c) standing en demi pointe (full toe-standing). Differences in control mechanisms with each posture were compared using stabilogram diffusion analysis. During open-loop control (short-term), toe-standing is less stable than heel-toe standing (P<0.05). There is greater stochastic activity when toe-standing (P<0.05), suggesting that any short-term instability is being compensated for by an increase in muscle activity across the lower joints. During closed-loop control (long-term), there is no difference in mediolateral (ML) stochastic activity (increased activity has been linked to falls) between toe-standing and heel-toe standing. In addition, toe-standing is more stable than heel-toe standing (P< s0.05). Toe-standing, in and of itself, may not be responsible for balance problems in populations who compulsorily toe-stand.
Nolan
Lee
L
Department of Biomedical Engineering, Centre for Biodynamics, Boston University, Boston, MA, USA. lnolan@ihs.se
Kerrigan
D Casey
DC
D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006365:Heel; D006801:Humans; D008297:Male; D004856:Postural Balance; D014034:Toes