EMG-driven force with a compliant tendon

Forward pipeline as emgDrivenForce() but with tendon compliance: at each time the muscle-tendon force equilibrium is solved for the fiber length (quasi-static), so tendon stretch is accounted for. Requires the MTU length trajectory (e.g. from muscleTendonKinematics()).

Usage

emgDrivenForceElastic(
  emg,
  mtu_length,
  sr,
  optimal_fiber_length,
  tendon_slack_length,
  params = emgDrivenParams()
)

Arguments

emg

EMG envelope.

mtu_length

MTU length (m); scalar or same length as emg.

sr

Sampling rate (Hz).

optimal_fiber_length, tendon_slack_length

Muscle geometry (m).

params

Parameter list from emgDrivenParams().

Value

Muscle-tendon force time series (N).

Examples

sr <- 500; t <- seq(0, 1, by = 1 / sr)
emg <- pmax(sin(2 * pi * 2 * t), 0)
f <- emgDrivenForceElastic(emg, mtu_length = 0.30, sr = sr,
                           optimal_fiber_length = 0.10,
                           tendon_slack_length = 0.19)
max(f)
#> [1] 979.6609