What results do I need to answer my research question?

  1. Joint angles
  2. Net joint moments
  3. Muscle forces
  4. Muscle fiber lengths
  5. Predicted control signal

What elements of a model might these results be sensitive to?

  1. I am interested in muscle fiber length in the plantar flexors. These will be sensitive to activation, architecture parameters, and tendon stiffness, but not knee varus/valgus angle or segment intertial parameters
  2. I am interested in knee joint contact forces.  These will be sensitive to the knee joint definition and relative strengths of muscles crossing the knee, but not very sensitive to tendon stiffness.
  3. I am interested in how a CMC controller predicts a different activation pattern when I change tendon stiffness.  This will be sensitive to activation dynamics, but not to knee joint definition.

In what ranges will my study be conducted and in what ranges has the model been validated?

  1. I am studying walking, where knee angles do not exceed 75 deg.  A model that has been validated up to 100 deg is sufficient.
  2. I am studying running, where knee angles may reach 125 deg.  A model that has only been validated up to 100 deg is insufficient.