The analysis of the data has shown that the thigh had a greater range of motion, as well as a greater angular velocity for the stair climbing movement. The hip joint also experienced a greater range of motion during stair climbing than the Stairmaster climbing. However, the knee experienced approximately the same range of motion for both stair climbing and Stairmaster climbing. Therefore, the exercise of the knee was equivalent in these two movements. However, the Stairmaster climbing was better for individuals with a limited range of motion or mobility in the hip joint.
One major difference between the Stairmaster and stair climbing motions was the swing phase in stair climbing. During the swing phase, the limb was not in contact with the ground reducing the amount of forces on that limb. However, the ground reaction force was concentrated on the other leg in contact with the ground. The stair climbing caused the body to generate larger forces, because the individual was required to lift the thigh using the hip flexors. The Stairmaster climbing differed, because the individual was not required to lift the thigh solely using hip flexors. The machine to some extent helped reduce the amount of force necessary for hip and thigh flexion. While one leg pushed down on the apparatus, the other leg was lifted by the machine. Also, by climbing stairs the leg has to lift the entire body up the stair which is generally between 12.5 cm and 20 cm high (Kroemer, Kroemer, Kroemer 127). The vertical displacement of the Stairmaster (10 cm) was less than the average height of stairs, minimizing the amount of work required by the subject. The Stairmaster was a good exercise machine for individuals who have a high risk of injury, although the body would not work as hard when compared to climbing stairs for the same period of time. There is a trade-off between the two movements: Stair climbing is the most effective in providing a quality workout and use of the Stairmaster minimizes the risk of injury.
There are several studies that exist when doing biomechanical studies. First of all, this study involved only one subject. To come to a solid conclusion, it is necessary to study several individuals of different weights and statures. Another factor that could affect the results was human and equipment error. The calculations may not be entirely accurate based on software and human calculation error. Time was also a limiting factor in this study. The next step of this analysis would be to study which brand of Stairmaster best simulates climbing stairs. In addition, the forces should be analyzed to determine which type of exercise produced the least amount of load and torque on the body.
Kroemer, Karl, Henrike Kroemer, Katrin Kroemer-Elbert. Ergonomics: How to Design for Ease and Efficiency. Englewood Cliffs: Prentice Hall, 1994.