biodex BALANCE SYSTEM SD - Page 85

T
he “Score” is defined as the standard deviation of position over the length of the test. The
Standard deviation is interpreted to be the absolute vector length deviation from the mean vec-
tor end point. Basically, all vectors (X,Y) coordinates are summed and divided by the number of
samples, to obtain a vector sum which represents the position of the mean.
and
N-1 22
φ = sqrt(Σ((Xn-sx)+(Yn-sy) )
n = 0
N
CONTENTS
— A-3 — APPENDIX A
Xn
N =1
N =0
sx
Yn
N =1
N =0
sy