Movement Analysis Flashcards
Fulcrum
The part of a lever system that pivots; joints are the fulcrums in the body’s lever systems.
Resistance
The load to be moved by a lever system; usually this involves weight when the body’s lever systems are involved.
Effort
The force applied to move the resistance or weight; in the body, the effort is provided by muscles exerting a force.
First class lever
Found at the elbow joint, where the triceps causes extension of the lower arm.
Second class lever
Found at the ankle, where the gastrocnemius causes plantar flexion.
Third class lever
The majority of the body’s joints act as third class levers; for example, the biceps acting at the elbow to cause flexion acts as a third class lever system.
Mechanical advantage
The benefit to a lever system of having either a short effort arm - giving rapid movements over a large range of movement - or a short resistance arm - giving the advantage of being able to move a heavy weight.
Agonist
The prime mover - muscle that causes movement.
Antagonist
Muscle that relaxes to allow the agonist to contract.
Isotonic
Muscle action where the muscle changes length - causes movement.
Isometric
Muscle action where the muscle stays the same length - used in balances.
Concentric
Isotonic contraction where the muscle shortens.
Eccentric
Isotonic contraction where the muscle lengthens - used to control downward movements.
Sagittal plane and transverse axis
Plane and axis for forwards and backwards movements - direction for extension and flexion.
Frontal plane and sagittal axis
Plane and axis for side to side movements - direction for abduction and adduction.
Transverse plane and longitudinal axis
Plane and axis for rotating movements - direction for rotations and spins.
Deltoid
Muscle causing flexion and abduction at the shoulder.
Latissimus dorsi
Muscle causing extension and adduction at the shoulder.
Biceps
Muscle causing flexion at the elbow.
Triceps
Muscle causing extension at the elbow.
Hamstrings
Group of muscles causing flexion at the knee.
Quadriceps
Group of muscles causing extension at the knee.
Hip flexors
Main agonists at the hip during hip flexion.
Gluteals
Main agonists at the hip during hip extension.
Tibialis anterior
Muscle causing dorsiflexion at the ankle.
Gastrocnemius
Muscle causing plantar flexion at the ankle.
Rotator cuff
Group of muscles causing rotation at the shoulder.
