A prosthetic foot has a frame, a forefoot keel, a heel keel, and an adjustable spring member. The frame couples to a prosthetic leg. The forefoot keel includes a first resilient substrate extending from the frame to the anterior end of the foot. The heel keel member includes a second resilient substrate extending from the frame to the posterior end. The first and second resilient substrates are load bearing substrates for a walking human. The adjustable spring member includes a third resilient substrate and a brake. The third resilient substrate has a first end directly or indirectly coupled to the brake, and a second end coupled to the forefoot keel proximate to the anterior end. The third resilient substrate extends through or around the first resilient member and the second resilient member. The brake provides resistance to the travel of the first end of the third resilient substrate in the superior direction.