Adaptation of lower limb movement patterns when maintaining performance in the presence of muscle fatigue.
Adaptations in lower limb movement patterns were examined when performance was maintained during a fatiguing repetitive loading task. Forty recreationally active male and female participants performed single-leg hopping to volitional exhaustion at 2.2Hz to a submaximal height. Spatio-temporal characteristics, mechanical characteristics and variability of the knee-ankle and hip-knee joint couplings were determined at 20% increments during the duration of the hopping task. Variability of the knee-ankle and hip-knee couplings in the flexion/extension axis significantly increased during the loading and propulsion phases during the hopping task (p<0.05). Performance (vertical stiffness, hopping frequency and height) did not change significantly during the task (p>0.05), however foot contact time increased progressively during this task (p<0.05) and maximum hop height significantly decreased after the task (p<0.05). The observed increase in variability between adjoining lower limb segments demonstrated the ability of the neuromotor system to adapt and maintain performance even with the onset of fatigue. This finding highlights that during the performance of a rapid and repetitive loading activity, performance can be preserved when there is variability in the neuromotor system.
School of Science and Health, Western Sydney University, Sydney, NSW, Australia. Electronic address: K.Mudie@westernsydney.edu.au.
Kurt L
KL
Mudie
School of Science and Health, Western Sydney University, Sydney, NSW, Australia.
Amitabh
A
Gupta
School of Science and Health, Western Sydney University, Sydney, NSW, Australia.
Simon
S
Green
School of Science and Health, Western Sydney University, Sydney, NSW, Australia.
Peter J
PJ
Clothier
D000222:Adaptation, Physiological / Q000502:physiology*; D000842:Ankle / Q000033:anatomy & histology / Q000502:physiology; D001696:Biomechanical Phenomena; D005260:Female; D005528:Foot / Q000502:physiology; D006621:Hip Joint / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D007717:Knee / Q000033:anatomy & histology / Q000502:physiology; D007719:Knee Joint / Q000033:anatomy & histology / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D055815:Young Adult
Fatigue; Hopping; Joint coupling variability; Motor control