Compare left and right plantar pressure

Calculates the signed Robinson symmetry index: $$100 (L-R) / ((L+R)/2).$$

Usage

pressureAsymmetry(
  left,
  right,
  metric = c("peak_pressure", "pti", "contact_area", "total_force"),
  force_factor = 0.001
)

Arguments

left, right

Left and right pressure_movie objects.

metric

Scalar metric to compare.

force_factor

Conversion from pressure times cell area to force.

Value

A pressure_asymmetry object containing side values, signed and absolute symmetry indices, and the left/right ratio.

References

Robinson RO, Herzog W, Nigg BM (1987). Use of force platform variables to quantify the effects of chiropractic manipulation on gait symmetry. Journal of Manipulative and Physiological Therapeutics, 10:172-176.

Examples

left <- pressureMovie(array(100, c(3, 3, 5)), 100, side = "left")
right <- pressureMovie(array(80, c(3, 3, 5)), 100, side = "right")
pressureAsymmetry(left, right)
#> <pressure_asymmetry> metric=peak_pressure
#>   left: 100  right: 80  SI: 22.22%  |SI|: 22.22%