Calculate center of pressure (COP) from force-plate data

Computes COP coordinates from force and moment components using standard force-plate equations (assuming a vertical Z axis).

Usage

calculateCOP(forces, moments, origin = c(0, 0, 0), min_vertical_force = 20)

Arguments

forces

Matrix/data.frame with at least three columns for force components (X, Y, Z).

moments

Matrix/data.frame with at least three columns for moment components (X, Y, Z).

origin

Numeric length-3 vector with force-plate origin (x, y, z).

min_vertical_force

Minimum absolute vertical force required to compute COP (samples below this threshold are set to NA).

Value

A data.frame with columns cop_x, cop_y, cop_z, free_moment, and vertical_force.

References

Winter DA (2009). "Biomechanics and Motor Control of Human Movement." 4th ed. John Wiley & Sons.

See also

analyzeForcePlate() for comprehensive force plate analysis, calculateCOM() for whole-body center of mass computation.

Examples

f <- cbind(Fx = rep(0, 10), Fy = rep(0, 10), Fz = rep(1000, 10))
m <- cbind(Mx = rep(100, 10), My = rep(-200, 10), Mz = rep(0, 10))
cop <- calculateCOP(f, m)