Compute vertical loading rate from GRF

Detects stance phases from a vertical GRF signal and computes loading rate from initial contact to peak force for each stance.

Usage

computeLoadingRate(
  vgrf,
  sampling_rate,
  threshold = 20,
  method = c("instantaneous", "average")
)

Arguments

vgrf

Numeric vector or matrix of vertical GRF values.

sampling_rate

Sampling rate in Hz.

threshold

Contact threshold in force units.

method

Loading-rate method: "instantaneous" (max slope) or "average" (peak rise over time-to-peak).

Value

For vector input: a data.frame with one row per stance. For matrix input: same data.frame with an added channel column.

References

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

See also

analyzeForcePlate() for comprehensive force plate analysis, computeImpulse() for impulse computation.

Examples

grf <- c(rep(0, 100), seq(0, 800, length.out = 150),
         seq(800, 0, length.out = 150), rep(0, 100))
computeLoadingRate(grf, sampling_rate = 1000)
#>   stance onset peak time_to_peak peak_force loading_rate
#> 1      1   105  250        0.145        800     5369.128