Abstract: Composite springs, composite spring assemblies, medical devices including the same, and methods of making and using the same are disclosed. The composite springs may comprise alternating layers of carbon fiber and fiberglass materials. A strengthening adhesive, such as an epoxy, may be used to bind the carbon fiber and fiberglass materials. A dampening member may be attached to the composite spring, thereby at least partially defining a composite spring assembly. The dampening member may dampen elastic/spring forces of the composite spring. The composite spring assembly may be attached to an orthotic device to provide a non-linear spring response during movement of the device.