As a result of the growing concern for wellness, body image, and physical fitness in the United States, the development of many exercise machines has grown. Among these machines, the use of stair-steppers appears to be growing the fastest according to American Sports Data (Ryan et al., 1994). An interesting aspect to stair-stepping on a machine such as the Stairmaster is the ability of the participant to step either forwards or backwards. Differences must result from the two motions because data from past studies show that backwards stepping at a high rate increases one's heart rate and caloric expenditures higher than stepping forward (Andriacchi et al., 1980). Stair-stepping on a Stairmaster in both the forward and backward directions is also used for rehabilitation, specifically in the knee joint (Zimmerman et al., 1994). Our project should allow us to realize the importance of utilizing the two movements for rehabilitation and physical fitness, something we are interested in knowing. Overall, we would like to understand what biomechanical differences occur when stepping forward as opposed to backwards on a Stairmaster. By answering this question we will have a better understanding of what both forward and backward stepping exercises are beneficial for.
Overall, the purpose of our study is to observe as well as compare the biomechanical differences that result in the upper leg segment, knee joint, and ankle joint when stepping forward and backwards on a Stairmaster. By observing the specific angles at the knee joint and ankle joint as well as the position of the upper leg, we should be able to compare the biomechanical difference between using the Stairmaster in forward and backward positions. From the conclusion of our data and additional research we also hope to compare how backwards and forwards stepping is beneficial in exercise and rehabilitation.