Lower leg characteristics influance on hopping height

Abstract

It has been suggested that certain lower leg variables affects running and jumping performance. However, it is unclear how these variables interact with each other, and how they jointly affect hopping performance. We assume that AT-MA influences the physical performance differently depending upon biomechanical variables of the plantar flexor muscles. We hypothesize that no single variable can explain hopping height, rather a combination of lower leg variables can explain the variation in hopping height. Healthy young adults (n = 28, age 21.8 ±4.0 yrs) performed serial hops on a force plate during which we recorded right leg joint kinematics, lateral gastrocnemius fascicle behavior, and plantar flexor electromyography activity. We found no correlation between hopping height and AT-MA (r=0.28, p=0.14). Multiple regression analyses revealed that variations in AT-MA, ankle dorsiflexion amplitude, and peak ground reaction force explained 53% of the variation in hopping height. We concluded that even a combination of selected biomechanical variables can only moderately account for hopping performance.