Gait Deviation Index (Schwartz & Rozumalski 2008)

Scores overall gait pathology on a scale where the normative control population averages 100 with a standard deviation of 10 (by construction); values below 100 indicate greater deviation, each 10 points corresponding to one standard deviation. The subject's nine kinematic curves are projected onto the normative feature basis, and the log of the distance to the control mean is standardised against the control distribution.

Usage

gaitDeviationIndex(kinematics, norm = NULL, basis = NULL, n_features = 15L)

Arguments

kinematics

Subject kinematics (see gaitVariableScore()); curves are time-normalised to the basis's point count (typically 51).

norm

A gait_norm reference (from PhysioGaitNorm::loadGaitNorm()); if NULL, loaded from PhysioGaitNorm. Ignored when basis is supplied.

basis

An optional precomputed gdiBasis() (reuse across many subjects); if NULL it is built from norm.

n_features

Number of gait features when building the basis (default 15).

Value

A gait_deviation_index object: a list with gdi (numeric), distance, z, and n_features.

References

Schwartz MH, Rozumalski A (2008). Gait & Posture 28(3):351-357.

See also

gdiBasis(), gaitProfileScore()