The Effect Of Fatigue On Sub-System Joint Work: The Influence Of Sex, Strength, And Eccentric Loading

Typically expressed in forms of positive, negative, and net work, locomotive energy is dispersed through each joint and can be affected by changes in conditions, sex, and fatigue. At increased loads, females and weaker individuals utilize a knee-dominant model, and males and stronger individuals utilize hip-dominant model (McBride & Nimphius, 2020). These changes have not been investigated with fatigue. The purpose of this study was to evaluate the effect of fatigue on different sex and strength joint work systems in the hip, knee, and ankle among healthy adults. Males and females were recruited to complete a countermovement jump and drop jumps from 15 cm, 30 cm, 45 cm, 60 cm, and 75 cm with a fatigue protocol between sets. Positive, negative, and net work were calculated for each subject in each jump trial, and data was evaluated based upon sex and strength striations. Results showed significant differences in ankle, knee, and hip work between jump types within groups, but no significant differences across groups. The fatiguing protocol produced a higher variability between jump types, but no significant differences in pre to post fatigue. The results of the current study have implications for future injury prevention and endurance-based sporting event research.