This is a detailed model of the human index finger, thumb and wrist. All muscles of the index finger and thumb were modeled to match anatomical moment arm curves for each joint present in literature. All extrinsic muscles were modeled with appropriate wrist flexion/extension moment arms as well.
Each joint axes was modeled to match anatomical representations of the human index finger and thumb from literature. This is especially important for the multiple DOF of the thumb joints, which were modeled as non-orthogonal, non-intersecting axes of rotation.
Passive joint stiffness has been added to the finger and thumb joints as well, matching what is seen anatomically, this allows the model to react dynamically.

Model used in literature at: https://doi.org/10.1016/j.jbiomech.2018.06.017