Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

Russell D. Fischer


The purpose of this study was to investigate, through electromyography, whether forward or retrograde stair climbing on the StairMaster 4000 PT machine demonstrates a greater muscle contraction duration, differences in intensity of muscle contractions, or variation in initiation of muscle contractions. The muscles examined were the Rectus Femoris, Vastus Medialis, and Biceps Femoris. A gender difference was also evaluated.

Twenty-one subjects apparently healthy volunteered for this study. There were two groups of ten male subjects and eleven female subjects. Subjects were assigned to subgroups according to gender. The subgroups determined which position the subject was tested in first.

The descriptive data was analyzed using the Stat View TM SE+ Graphics. A repeated measures design was used to analyze On Time in seconds and percentage, Off Time in seconds and percentage, Muscle Initiation Time in seconds, and Average Mean Amplitude (muscular intensity) in centimeters. A MANOVA from SPSS was used to evaluated the repeated measures statistics.

There was a statistically significant difference for the On and Off Time for Rectus Femoris, Vastus Medialis, and Biceps Femoris. The data suggests a longer portion of on time for the retrograde position and a longer portion of off time for the forward position. There was a staistically significant difference for Average Mean Amplitude for the Rectus Femoris and Vastus Medialis. The data suggests a greater muscular intensity in the retrograde position.