The strength of the muscles across the ankle joint and the knee joint is important to maintain stability and prevent injury in the knee and ankle. For this reason, patients with ankle and knee joint injuries are rehabilitated to strengthen their muscles around the joints. Many approaches have been developed to enhance muscular strength, one of which is graded walking.1 The negative-heeled shoes (NHS), also known as earth shoes, were designed to mimic uphill walking so as to build up and exercise the muscles in the trunk and the lower limb. In the normal sports shoes, the heel was approximately 1.5 cm higher than the toe part; these were categorized as normal shoes.2 In contrast, the NHS have the toe part 1.5 cm higher than the heel, which tilts the foot into about 10° of dorsiflexion (Figure 28.1).