Anaerobic fatigue and its effect on kinematic and kinetic variables associated with impact during vertical jumping

Kinematic and kinetic variables associated with impacts during non-fatigued and fatigued vertical jumping were examined. The purpose of this study was to investigate fatigue and its effect on anterior/posterior shear forces, compression forces, and flexion/extension moments at the ankle, knee, and hip during an impact from vertical jumping. Twenty unskilled untrained females were tested isokinetically at 60 and 180 deg/s for leg extension and flexion strength. Leg strength was examined then retested two days later immediately following the Wingate Anaerobic Power test. This data was compared and used to quantify the amount of fatigue that would occur following the Wingate test. Non-fatigued and fatigued conditions were compared and significant differences were present for peak torque at 60 and 180 deg/s during both leg extension and flexion. Significant differences also occurred during the 25th repetition of leg extension and flexion at 180 deg/s. Non-fatigued and fatigued vertical jumps were performed approximately one week after the isokinetic leg testing. Non-fatigued countermovement vertical jumps were performed first with the fatigued jumps occurring second. The fatigued jumps were conducted immediately following the Wingate test. No differences were present for anterior/posterior shear forces, compression forces, and flexion/extension moments for the ankle, knee, and hip. There was a significant decrease in vertical jump height. It was concluded that kinetic changes in the joint did not occur because of a decrease in jump height. This was attributed to the lower extremity muscles being fatigued and as a result, the lower extremity muscles were unable to produce enough force to displace the body of the individual into the air for the same distance.