Load a normative gait reference dataset

Loads mean and standard-deviation kinematic waveform bands over the gait cycle for the nine Gait Deviation Index / Gait Profile Score kinematic variables, and (optionally) the normative feature reference set used to construct the Gait Deviation Index.

Usage

loadGaitNorm(
  dataset = "adult_reference",
  cycle = c(101, 51),
  age = NULL,
  speed = NULL,
  features = TRUE,
  reload = FALSE
)

Arguments

dataset

Dataset name; one of listGaitNorms()$dataset (default "adult_reference").

cycle

Gait-cycle length in points: 101 (default) or 51.

age

Optional age in years; if given it must fall within the dataset's age_min/age_max, otherwise an error is raised (this reference set is not stratified by age).

speed

Optional walking-speed condition (e.g. "self_selected"); if given it must match the dataset's speed.

features

Logical; if TRUE (default) also load the normative feature reference matrix (subjects x concatenated 51-point kinematics) used to build the GDI basis.

reload

Logical; force a re-read even if the dataset is cached.

Value

A gait_norm list with elements: dataset, version, cycle_length, percent (cycle sampling points), variables, mean and sd (each a length(variables) x cycle_length matrix, rows named by variable, columns named by cycle percentage), units, features (the feature matrix or NULL), and provenance (a one-row manifest data frame).

References

Schwartz MH, Rozumalski A (2008). "The Gait Deviation Index: a new comprehensive index of gait pathology." Gait & Posture 28(3):351-357. Baker R, et al. (2009). "The Gait Profile Score and Movement Analysis Profile." Gait & Posture 30(3):265-269.

See also

listGaitNorms()

Examples

norm <- loadGaitNorm("adult_reference", cycle = 101)
dim(norm$mean)
#> [1]   9 101
norm$variables
#> [1] "pelvic_tilt"        "pelvic_obliquity"   "pelvic_rotation"   
#> [4] "hip_flexion"        "hip_adduction"      "hip_rotation"      
#> [7] "knee_flexion"       "ankle_dorsiflexion" "foot_progression"