Summarize plantar loading by anatomical region

Partitions the active footprint along its anteroposterior extent using cumulative Cavanagh-style region bounds.

Usage

regionalLoading(
  pm,
  statistic = c("fti", "peak_force", "mean_force"),
  regions = c(rearfoot = 0.3, midfoot = 0.6, forefoot = 0.8, toes = 1),
  contact_threshold = 0,
  force_factor = 0.001
)

Arguments

pm

A pressure_movie.

statistic

Regional statistic: force-time integral, peak force, or mean force.

regions

Named, strictly increasing cumulative upper bounds ending at

1. Defaults to rearfoot, midfoot, forefoot, and toes.

contact_threshold

Pressure threshold in kPa defining loaded cells.

force_factor

Conversion from pressure times cell area to force.

Value

A regional_loading data frame with one row per region. Attributes contain the regional total and selected statistic.

References

Cavanagh PR, Rodgers MM, Iiboshi A (1987). Pressure distribution under symptom-free feet during barefoot standing. Foot and Ankle, 7:262-276.

Examples

pm <- pressureMovie(array(100, c(10, 4, 11)), 100, dx = 5, dy = 5)
regionalLoading(pm)
#> <regional_loading> statistic=fti, total=10
#>    region value pct_total peak_pressure contact_area n_cells
#>  rearfoot     3        30           100          300      12
#>   midfoot     3        30           100          300      12
#>  forefoot     2        20           100          200       8
#>      toes     2        20           100          200       8