GM model

can anyone help me understand the a1 and a0 values in the ligament.
in the code this is shown. the output from changing them completely alters the model but im not sure why. cheers

LigMdl = L0 = 0.03431717;
eps1 = 0.083;
F1 = …FootLigStiffnessScale*5.416326251;
a0 = 0.14;
a1 = 4.15;

PLease check the Reference Manual under