Tibiofemoral joint kinetics during squatting with increasing external load.
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.
Sahli
Sonia
S
Department of Physical Medicine and Functional Rehabilitation, Habib Bourguiba Hospital, University of Sfax, Tunisia.
Rebai
Haithem
H
Elleuch
Mohamed Habib
MH
Tabka
Zouheir
Z
Poumarat
Georges
G
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