# Biomechanics and Force

 The flashcards below were created by user elby317 on FreezingBlue Flashcards. What is biomechanics? The study of the forces and torques affecting movement and the description of the resulting movement What is force? A push or pull that either produces or has the capacity to produce a change in motion of the body What is net force? The sum of multiple forces from multiple directions acting on the body, which determines the resulting change in motion. Newton's 3 laws Law of InertiaLaw of AccelerationLaw of Reaction What is the law of inertia? A body will maintain it's state of rest or uniform motion in a straight line unless acted on by an external force What is the law of acceleration? Acceleration of a body resulting from an applied force will be:Proportional to the magnitude of the applied force, In the direction of the applied force, inversely proportional to the mass of the body. What is the formula for acceleration? a = f/m OR f = m*a f = forcea = accelerationm = mass What is the law of reaction? When two bodies interact, the force exerted by the first body on the second is met by an equal and opposite force exerted by the second body on the first. For every action, there is an equal and opposite reaction. Classifications of forces affecting movements reactionfrictionmuscular What is Ground Reaction Force (GRF)? Corresponds to Newton's law of reaction;As a body applies a force to the ground, the ground applies and equal and opposite force to the body How is GRF measured? Measured with a force plate in 3 directions:verticalanteroposteriormediolateralThe net effect of the 3-D forces determines the resulting movement GRF occurs in what activities? walkingrunning (higher force in running) How do you asses for abnormalities in gait? Evaluating ground reaction force patterns What is frictional force? When two objects interact, friction acts paralell to the surface contact of the object in a direction opposite the motion or impending motion. An example of frictional force When walking friction force occurs paralell to the ground in the opposite direction that you're walking Formula for Frictional Force Ff = mN Ff = frictional forcem = coefficient of friction -- nature and interaction of the contacting surfacesN = normal force -- force pressing the surfaces together What is muscle force? The pulling force on the bone that muscles provide;Must be present to move body segment; How do joints move? Through the net effect of individual muscle forces acting across the joint What influences movement, as it relates to muscle forces? The net muscular force and the distance the force acts from the rotational axis of the joint;The length of the muscle at the time of contraction;the velocity of muscles shortening What is torque? The rotary effect of force produced by a muscle or group of muscles How do normal joint movement patterns occur? From the coordinated actions of the muscles acting across the joint How do abnormal joint movement patterns occur? From disruptions in the coordinated muscular actions. Reasons abnormal joint movement occurs? Application of inappropriate forceCo-contraction of musculatureMuscular weaknessNeurological disorders affecting muscular recruitment Authorelby317 ID23993 Card SetBiomechanics and Force DescriptionBiomechanics, specifically force Updated2010-06-18T03:51:43Z Show Answers