title: The effect of local and general fatigue on knee proprioception.
abstract: OBJECTIVE
  The purpose of this study was to compare the effects of local and general fatigue loads on knee proprioception.
  
  
  METHODS
  Experimental controlled study.
  
  
  METHODS
  Proprioception of the knee joint was evaluated by measuring absolute angular error (AAE) at matching defined index angles before and after 2 different types of fatigue protocols (local load and general load) in 27 healthy male volunteers. Local load was provided with maximum isokinetic knee flexion-extension on the isokinetic dynamometer, and general load was 5 minutes running on a treadmill.
  
  
  RESULTS
  After local load, a significant decrease in peak torque of knee flexors and extensors was found, but no significant change in AAE was seen. In contrast, after general load, a significant increase of AAE was noted without significant muscle weakness.
  
  
  CONCLUSIONS
  The different results in previous studies evaluating the effect of fatigue on knee proprioception may have been affected by the difference of fatigue protocols, whether local or general load. Although local load was intended to produce local fatigue of the knee, which may cause dysfunction of muscle mechanoreceptors, general load may have produced general fatigue and affected other mechanisms in the proprioceptional pathway. The results of the present study suggest that decreased reproduction ability after general load is not due to the loss of peripheral afferent signals, but to other factors, especially deficiency of central processing of proprioceptive signals.
  
  
  CONCLUSIONS
  To prevent knee injury caused by fatigue-induced proprioceptional decline, muscle endurance training alone is not enough, and neuromuscular training, including central motor programming, is essential.
authors.affiliation: Department of Orthopaedic Surgery, Hirosaki University School of Medicine, Hirosaki, Japan. kazu3miura@aol.com
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Miura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tsuda
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Okamura
authors.forename: Hironori
authors.initials: H
authors.lastname: Otsuka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Toh
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001921:Brain / Q000502:physiology; D005221:Fatigue / Q000523:psychology*; D006801:Humans; D007718:Knee Injuries / Q000517:prevention & control; D007719:Knee Joint; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D009068:Movement; D009119:Muscle Contraction; D009928:Organ Specificity; D010807:Physical Endurance; D026741:Physical Therapy Modalities; D011434:Proprioception / Q000502:physiology; D019415:Torque; D016474:Weight-Bearing