chapter 2 - movement analysis Flashcards
what is the fulcrum
the part of a lever system that pivots; joints are the fulcrums in the body’s lever system
what is resistance
the load to be moved by the lever system; usually this involves weight
what is effort?
the force applied to move the resistance or weight; in the body the muscles are the effort
what is the acronym for levers
123FRETGB
example of a first class lever
tricep extension
example of second class lever
found at the ankle where the gastrocnemius causes plantar flexion
what is the pivot in the second class lever at the ankle
the toe joints
example of a third class lever
bicep contraction and elbow flexion
what is the most common lever type
third class
what is the formula for mechanical advantage?
mechanical advantage = effort arm / resistance arm
how does mechanical advantage work?
the further away the resistance is from the fulcrum (longer the resistance arm), the larger forces the required by the effort to move this load.
which lever systems have a lower mechanical advantage
first and third class
which lever system has the highest mechanical advantage
second class lever systems
what is the agonist
the prime mover, the muscle that causes movement
what is the antagonist
the muscle that relaxes to allow the agonist to contract
what are tendons
they attach muscle to bones
what can muscles do
they can only contract and pull
what is antagonistic muscle contraction?
when the muscles work in pairs to contract and relax
what are tendons made of
very strong cords of connective tissue
what is isotonic contractions
muscle action where the muscle changes length - causes movement
what is isometric contraction
muscle action where the muscle stays the same length - used in balances
what is concentric contractions
isotonic contraction where the muscle shortens
what is eccentric contractions
isotonic contraction where the muscle lengthens - used to control downwards movements
what muscle group usually controls the eccentric contractions
the agonist
what is the mnemonic for planes and axis
Some Times - Sagittal Frontal
Fun Starts - Frontal Saggital
Too Late - Transverse Longitudinal
how does the sagittal plane divide the body
through the centre, dividing the body into left and right parts
what movements occur in the sagittal plane and transverse axis?
extension / flexion
how does the frontal plane divide the body
separates the front and back halves of the body
what movements occur in the frontal plane and sagittal axis?
abduction and adduction
how does the transverse plane divide the body?
cuts straight through the hips to divide the top half of the body to the bottom half.
what movement occurs in the transverse plane and longitudinal axis?
rotation
give a sporting example of flexion and extension
** walking
** running
** squats
** bicep curl
** leg extensions
** front somersault
give a sporting example of abduction and adduction
** star jump
** cartwheel
** side-bending
what is the main agonist causing flexion at the shoulders
deltoids
how does the shoulder move the arm during extension
backwards
how does the shoulder move the arm during flexion
forwards
what muscle causes flexion at the elbow
biceps
which muscle causes extension at the elbow
triceps
which muscle causes flexion at the knee
hamstrings
which muscle causes extension at the knee
quadriceps
which muscle is the main agonist during hip flexion
hip flexors
which muscle is the agonist of hip extension
the gluteals
which muscle causes dorsiflexion at the ankle
tibialis anterior
which muscle causes plantar flexion at the ankle
gastrocnemius
which muscle causes abduction in the shoulder
deltoid
which muscle causes adduction in the shoulder
latissimus dorsi
describe the pushing-up phase of a push-up in terms of muscle contraction and movement
the elbow is straightening so it is extension. the main agonist is the triceps and during this movement there is a concentric contraction of the triceps muscle.
describe the lowering-down phase of a push-up in terms of muscle contraction and movement
the elbow bends, this is flexion. this movement is controlled eccentrically by the triceps.
what is the drive phase in running
the short period of time where the performers foot is in contract with the ground and describes the performer pushing off the floor.
what happens during the drive phase of running (knee, hip, ankle)
knee straightens, (extension), this movement is brought about by a concentric contraction of the quadriceps muscle.
there is also hip extension brought by the concentric contraction of the gluteals
the performer pushes off the ground using their ankle joint, this involves plantar flexion caused by a concentric contraction of the gastrocnemius
what happens during the recovery phase of running (knee, hip, ankle)
the knee joint bends, flexion. caused by a concentric contraction of the hamstrings
the hip flexes, caused by a concentric contraction of the hip flexors
ankle adjusts, which is dorsiflexion. caused by the concentric contraction of the tibialis anterior
