Researchers have spent considerable time studying the mechanics and energy expenditure associated with human walking. These studies are generally conducted on flat treadmill surfaces despite the fact that people do not only walk on flat surfaces; they climb and move on different slopes every day, whether it be in the forest for a rugged hike or along the smooth floors of a shopping mall. From stairs to hillsides, we climb slopes every day, yet we have very little information on how our body does this, or how efficient we are at slope walking with regard to metabolic cost. Evidence leads us to believe there is a relation between the steepness of the slope and at what slope a person switches to “forefoot” walking – walking up on the toes or ball of the foot – rather than flat-footed walking. It is proposed that this switch may change the behavior of the muscles in the calf resulting in a change in efficiency.

Our study will focus on the degree of slope required to cause this “forefoot” switch as well as its connection to lower limb length and the evolution of human body proportions. Subjects will climb sloped treadmill at different degrees of steepness while motion capture models are created and metabolic energy consumption is recorded. With this, we will investigate how pressures from the environment on human skeletons and muscles may have influenced human evolution, as well as further the knowledge and understanding related to human movement.