title: Knee proprioception and strength and landing kinematics during a single-leg stop-jump task.
abstract: BACKGROUND
  The importance of the sensorimotor system in maintaining a stable knee joint has been recognized. As individual entities, knee-joint proprioception, landing kinematics, and knee muscles play important roles in functional joint stability. Preventing knee injuries during dynamic tasks requires accurate proprioceptive information and adequate muscular strength. Few investigators have evaluated the relationship between knee proprioception and strength and landing kinematics.
  
  
  OBJECTIVE
  To examine the relationship between knee proprioception and strength and landing kinematics.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Fifty physically active men (age = 26.4 ± 5.8 years, height = 176.5 ± 8.0 cm, mass = 79.8 ± 16.6 kg).
  
  
  METHODS
  Three tests were performed. Knee conscious proprioception was evaluated via threshold to detect passive motion (TTDPM). Knee strength was evaluated with a dynamometer. A 3-dimensional biomechanical analysis of a single-legged stop-jump task was used to calculate initial contact (IC) knee-flexion angle and knee-flexion excursion.
  
  
  METHODS
  The TTDPM toward knee flexion and extension, peak knee flexion and extension torque, and IC knee-flexion angle and knee flexion excursion. Linear correlation and stepwise multiple linear regression analyses were used to evaluate the relationships of both proprioception and strength against landing kinematics. The α level was set a priori at .05.
  
  
  RESULTS
  Enhanced TTDPM and greater knee strength were positively correlated with greater IC knee-flexion angle (r range = 0.281-0.479, P range = .001-.048). The regression analysis revealed that 27.4% of the variance in IC knee-flexion angle could be accounted for by knee-flexion peak torque and TTDPM toward flexion (P = .001).
  
  
  CONCLUSIONS
  The current research highlighted the relationship between knee proprioception and strength and landing kinematics. Individuals with enhanced proprioception and muscular strength had better control of IC knee-flexion angle during a dynamic task.
authors.affiliation: Neuromuscular Research Laboratory, University of Pittsburgh, PA 15203, USA. tnagai@pitt.edu
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Sell
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: House
authors.forename: John P
authors.initials: JP
authors.lastname: Abt
authors.forename: Scott M
authors.initials: SM
authors.lastname: Lephart
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D016014:Linear Models; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D019415:Torque