Fig. 3
From: Identifying human postural dynamics and control from unperturbed balance
Double inverted pendulum model with angle (\(q_i\)) and torque (\(\tau _i\)) sign conventions and parameter values for mass (\(m_i\)), length (\(l_i\)), center of mass (\(c_i\)), and moment of inertia about center of mass (\(j_i\)). The direction of gravity (g) is also defined