Table A1.

List of symbols used in the Appendix.

M 𝑆	Torque at the interface of the spring and simple support
M 𝐴	Torque at the ankle joint
d	Absolute distance between the ankle joint and the interface of the spring and simple support
L	Absolute distance between the cam follower and the interface of the spring and simple support
r	Cam radius
𝜃𝑐𝑎𝑚	Rotation of the cam profile
σ	The angle between d and L at the neutral ankle angle 𝜃𝑐𝑎𝑚
𝛾 0	Angular deflection of the rotary spring, due to a preload
𝛾	Rotation of the rotary spring
k	The rotational stiffness of the cantilever beam spring, around the simple support
ω	Angle between d and the vertical axis
𝛼	Angle between r and the vertical axis, caused by the horizontal displacement of the cam follower due the rotary motion of the spring
𝜓	Effective cam profile angular deflection, accounting for 𝛼
𝛿	Change in ankle angle due to elastic deflection of the frame