title: Tibiofemoral joint kinetics during squatting with increasing external load.
abstract: BACKGROUND
  There is limited information about the effects of increasing load while squatting.
  
  
  OBJECTIVE
  To quantify tibiofemoral joint kinetics during squatting with variable loads.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  20 male students.
  
  
  METHODS
  Tibiofemoral joint kinetics and electromyographic (EMG) activity of four involved muscles were determined by recording the half squat with variable external loads.
  
  
  METHODS
  Tibiofemoral joint force and external moment components and EMG activity of four involved muscles.
  
  
  RESULTS
  Throughout the exercise, a posterior direction for the antero-posterior shear force and a net extension for the external moment were observed. They increased with knee flexion reaching peak force of 29% of the subject body weight (BW) and moment of 88Nm (without external load). All force and moment components and muscle activities increased as the external load increased.
  
  
  CONCLUSIONS
  These findings suggest that half squat may be safe to use for quadriceps strengthening with very low potential loading on the anterior cruciate ligament (ACL). Our data can help clinicians choose the appropriate external load.
authors: Department of Physical Medicine and Functional Rehabilitation, Habib Bourguiba Hospital, University of Sfax, Tunisia.
authors: Sonia
authors: S
authors: Sahli
authors: Haithem
authors: H
authors: Rebai
authors: Mohamed Habib
authors: MH
authors: Elleuch
authors: Zouheir
authors: Z
authors: Tabka
authors: Georges
authors: G
authors: Poumarat
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D005269:Femur / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D010865:Pilot Projects; D052097:Quadriceps Muscle / Q000502:physiology*; D013977:Tibia / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult