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Tibial Acceleration and Spatiotemporal Mechanics in Distance Runners During Reduced Body Weight Conditions
Journal of Sport Rehabilitation
  • Matthew F. Moran, Sacred Heart University
  • Brendan J. Rickert, Sacred Heart University
  • Beau K. Greer, Sacred Heart University
Document Type
Peer-Reviewed Article
Publication Date
Exercise Science
Context: Treadmills that unload runners via a differential air pressure bladder (DAP; e.g. AlterG Anti-Gravity Treadmill) are commonly used to reduce effective body weight in a clinical setting, however, the relationship between the level of unloading and tibial stress is currently unknown. Objective: To determine the relationship between tibial impact acceleration and level of body weight (BW) unloading during running. Design: Cross-sectional. Setting: University motion-analysis laboratory. Participants: 15 distance runners (9M, 6F; 20.4 ± 2.4 years; 60.1 ± 12.6 kg). Interventions: None. Main Outcome Measures: Peak tibial acceleration and peak-to-peak tibial acceleration was measured via a uniaxial accelerometer attached to the tibia during a 37-min continuous treadmill run that simulated reduced BW conditions via a DAP bladder. The trial began with a 10-min run at 100% BW followed by nine 3-min stages where BW was systematically reduced from 95% to 60% in 5% increments. Results: There was no significant relationship between level of BW and either peak tibial acceleration or peak-to-peak tibial acceleration (p>.05). Both heart rate and step rate were significantly reduced with each 5% reduction in BW level (p<.01). Conclusions: Although ground reaction forces are reduced when running in reduced BW conditions on a DAP treadmill, tibial shock magnitudes are unchanged as an alteration in spatiotemporal running mechanics (e.g. reduced step rate) may nullify the unloading effect.

epub ahead of print 2016

Citation Information

Moran, M.F., Rickert, B.J., & Greer, B.K. (2017). Tibial acceleration and spatiotemporal mechanics in distance runners during reduced body weight conditions. Journal of Sport Rehabilitation, 26(3), 221-226. doi: 10.1123/jsr.2015-0141