Abstract
BACKGROUND: The need for a commentary on eccentric vs concentric movement profiles stems from the innate difference in biomechanical activity during each of the two phases of movement. While all involved muscles experience stress and/or fatigue throughout the course of the exercise, the emerging nature of the stress and/or fatigue can be attributed differently at different points. The Bilateral Asymmetry index (BAI) may present in different ways in accordance with how the stresses/fatigue present. Given this variation in function, there is a need to identify eccentric vs concentric BAI. PURPOSE: Exploring the difference in BAI for an eccentric vs concentric phase of a pushup motion. METHODS: Subjects were instructed to perform as many pushups as possible on the split belt Bertec treadmill. The Vicon camera system was used to track marker position which was placed on the cervical vertebrae five. Using the vertical trajectory of the marker, we identified and segmented the eccentric and concentric portions of individual pushups using custom MATLAB script. The Bilateral Asymmetry Index was calculated for each phase of the pushup. The was done using the mean force produced by the left and right sides independently during each pushup repetition. We compared the BAI between eccentric and concentric phases of each pushup for each subject. RESULTS: The number of pushups performed by subjects ranged from 8-52 across 10 subjects. The average BAI for eccentric phase was 3.82 ± 2.56. While the average BAI for concentric phase was 3.51 ± 2.51. CONCLUSION: We have validated this methodology to measure interlimb asymmetry. This validated measure is part of an ongoing study analyzing the effect of an asymmetrical weightlifting program in bilateral force production.
Recommended Citation
Broaddus, Olivia D.; Barras, Miah; Martinez-Diaz, Dacia; Layne, Charles; and Johnston, Craig
(2026)
"Concentric vs. Eccentric Asymmetry in Force Production During Pushups,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
18, Article 225.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss18/225