B-46 Free Communication/Slide - Biomechanics: MAY 28, 2008 3:15 PM - 5:15 PM ROOM: 106
Treadmills are often used to perform running analyses. Kinetic comparisons between overground (OG) and treadmill (TM) running have demonstrated similar mechanics. However, no studies have compared OG and TM running 3D kinetics.
PURPOSE: To compare 3D running kinetics between OG and TM running.
METHODS: This is an ongoing study, with 5 subjects examined so far. Subjects were recreational runners, 3 females and 2 males, 23.2 ± 5.2 years, running at least 7 miles per week (19.8± 11.7). Subjects were tested while running at 3.35 m/s OG (Bertec, Worthington, Ohio) and on an instrumented TM (AMTI, Watertown, Mass). Forceplate data were collected at 1000 hz. Variables of interest included vertical impact and propulsive peaks, vertical loading rate, braking and propulsive, and medial and lateral forces. Additionally, peak positive acceleration (vertical) was also collected with a tri-axial accelerometer (PCB Piezotronics, Depew, NY) at 1000 hz. The accelerometer was attached to the anteromedial aspect of the dominant limb's distal tibia.
RESULTS: With the exception of peak lateral and peak medial forces, these preliminary data suggest that kinetics are similar between OG and TM running (<10% difference). Peak lateral (+22.7% difference) and peak medial (+37.8% difference) forces all demonstrated greater values for TM running versus OG running. These greater forces may represent a stabilizing strategy on the part of the subjects to prevent side to side drifting on the TM belt.
CONCLUSIONS: With the exception of peak lateral and peak medial forces, these preliminary results suggest that TM running is an adequate representation of OG running kinetics.