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Scale a body model from marker-measured segment lengths

Source: R/kinetics-rne.R
scaleBodyModel.Rd

Measures each lower-limb segment length from joint-centre trajectories (the mean over frames of the distance between the segment's endpoints) and scales the de Leva model to the subject's body mass with those measured lengths.

Usage

scaleBodyModel(joints, body_mass, model = c("deLeva_male", "deLeva_female"))

Arguments

joints

A matrix/data.frame with ankle, toe, knee, hip joint coordinate columns (_x/_y, plus _z for 3D), as for inverseDynamicsRNE().

body_mass

Subject body mass in kg.

model

"deLeva_male" or "deLeva_female".

Value

A segment inertia data.frame with the marker-measured length.

See also

scaleSegmentModel(), inverseDynamicsRNE()

Examples

n <- 10
joints <- data.frame(
  ankle_x = rep(0, n), ankle_y = rep(0.08, n), toe_x = rep(0.15, n),
  toe_y = rep(0.03, n), knee_x = rep(0, n), knee_y = rep(0.48, n),
  hip_x = rep(0, n), hip_y = rep(0.90, n))
scaleBodyModel(joints, body_mass = 70)
#>   segment    length  mass mass_fraction com_proximal_fraction
#> 1    foot 0.1581139 1.015        0.0145                 0.500
#> 2   shank 0.4000000 3.255        0.0465                 0.433
#> 3   thigh 0.4200000 9.912        0.1416                 0.433
#>   radius_gyration_fraction     inertia
#> 1                    0.475 0.005725234
#> 2                    0.302 0.047499043
#> 3                    0.323 0.182416836