Table 2.

List of the seven different muscles used in the FBL and derived models: GLU for gluteus, HF for hip flexor, VAS for vasilus, GAS for gastrocnemius, TA for tibialis, HAM for hamstring and SOL for soleus.

MTUs list and joints related parameters
	Action	r0[m]	φmax[deg]	φref[deg]
GLU	hip ext.	0.1	–	150
HF	hip flex.	0.1	–	180
VAS	knee ext.	0.06	165	125
SOL	ankle ext.	0.05	110	80
TA	ankle flex.	0.04	80	110
HAM	hip ext. knee flex.	0.08	−, 180	155, 180
GAS	ankle ext. knee flex.	0.05	110, 140	80, 165

The last two rows (HAM and GAS muscles) corresponds to bi-articular muscles (i.e., they span two joints), other rows are for uni-articular muscles. The second column shows the resulting action on the joint(s) onto which the muscle acts. The third column corresponds to the lever arm used for torque calculation. The fourth column gives the angle at which the action of the muscle on the joint is maximum (absent for the hip joint). The last column gives the reference angle of the muscle (i.e., the angle that corresponds to the muscle rest length).