biodex BALANCE SYSTEM SD - 11 System Utilities

M
edial/Lateral (M/L) Stability Index: Represents the variance of foot platform displacement in
degrees, from level, for motion in the frontal plane.
Mean Deflection: Average position for the patient in all motions throughout the test.
A/P Mean Deflection: Average position of side-to-side motion for the patient throughout the test.
M/L Mean Deflection: Average position for the patient in the frontal plane throughout the test.
Standard Deviation: The amount of variability in the statistical measure. A low standard deviation
demonstrates that the range of values from which the mean was calculated were close together.
 Mean, A/P and M/L Deflections are from the patient’s actual position in contrast to the Stability
Index, which is a variance from level as established during the centering patient portion of the test proto-
col. The resulting scores for Mean, A/P and M/L Deflections are not statistically effected by the centering
process.
12. SYSTEM UTILITIES
REPORTS — 9-2 —
∑ (0 - X)
2
number of samples
Medical/Lateral Stability Index =
=
(
Dlx =
=
(
∑ (X
n
, Y
n
)
Mean Deflection =
n
n
n
∑ Y
n
n
A/P Mean Deflection =
n
n = # of samples
Y
n = n th sample
∑ X
n
n
M/L Mean Deflection =
n
n = # of samples
X
n = n th sample
X
n
2
+ Y
n
2
(X
n
, Y
n
) =
(position vector magnitude)
∑
∑ (X
n
- X)
2
n
Standard Deviation =
n
n = # of samples
X
n = n th sample
X = mean deflection
n