To determine whether peak vertical and horizontal impact accelerations were different while running on a track or on a treadmill, 12 healthy subjects (average age 32.8 ± 9.8 y), were fitted with a novel, wireless accelerometer capable of recording triaxial acceleration over time. The accelerometer was attached to a custom-made acrylic plate and secured at the level of the L5 vertebra via a tight fitting triathlon belt. Each subject ran 4 miles on a synthetic, indoor track at a self-selected pace and accelerations were recorded on three perpendicular axes. Seven days later, the subjects ran 4 miles on a treadmill set at the individual runner’s average pace on the track and the peak vertical and horizontal impact magnitudes between the track and treadmill were compared. There was no difference (P = .52) in the average peak vertical impact accelerations between the track and treadmill over the 4 mile run. However, peak horizontal impact accelerations were greater (P = .0012) on the track when compared with the treadmill. This study demonstrated the feasibility for long-term impact accelerations monitoring using a novel wireless accelerometer.
Erin M.R. Bigelow is with the Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI. Niell G. Elvin (Corresponding Author) is with the Department of Mechanical Engineering, City College of New York, New York, NY. Alex A. Elvin is with the School of Civil Engineering, University of the Witwatersrand, Johannesburg, South Africa. Steven P. Arnoczky is with the Laboratory for Comparative Orthopaedic Research, Michigan State University, East Lansing, MI.