Biomechanics Flashcards
What in the body acts as a lever
Long bones
What in the body acts as a fulcrum
joints
What in the body generates the effort
the muscle attached to the bone
First-class lever
has a fulcrum in the middle, between the force and the resistance
ex. occipital/atlus
Second-class lever
resistance is between the fulcrum and the applied force
ex. raising to the ball of your feet
Third-Class lever
force is applied between the resistance and the fulcrum
ex. biceps curl
3 types of muscle groups
agonists
antagonists
synergists
Also called a prime mover contracts to produce a particular movement
agonists
actions oppose those of the agonist
antagonists
Synergists
assist the prime mover in performing its action
the contraction contributes to tension exerted close to the insertion of the muscle or stabilizes the point of origin
may also assist an agonist by preveniting movement at a joint and thereby stabilizing the origin of the agonist
called fixators
Tendons attach
the muscle to bone, skin, or another muscle
Tendons usually have a ___, ____ strucuture
thick, cordlike
Aponeurosis
thin,flattened sheet, formed by tendons
The linea alba is an example of a what
aponeurosis
ligaments bind
bone to bone
what is the difference between an origin and insertion
origin- attachment site of tendon to less movable bone
insertion- attachment site of tendon to more movable bone
The insertion is pulled _______ the origin
toward
The origin typically lies _____ to the insertion
proximal
what kind of muscle is also called a sphincter because contraction of the muscle closes off the opening
circular
Muscle has widespread muscle fibers that converge on a common attachment site and are often triangular in shape
Convergent
What type of muscle has fasicles that run parallel to its long axis
parallel
Parallel muscles have a central body, called the _____, or gaster
belly
What type of muscle organization have one or more tendons extending through their body, and the fascicles are arranged at an oblique angle to the tendon
Pennate
What muscle organization have the most power per square area
pennate
The mandible is what type of lever
3rd class lever
distance between axis and point of resistance application
resistance arm
distance between axis and point of force
force arm
FxFa (force arm)=
Resistance x Resistance arm (RA)
Stermocleidomastoid is an example of what
parallel strap-like muscle
The biceps brachii is an example of what
parallel:fusiform muscle (fusiform beceause it has two head)
Pectoralis major is an example of what
convergent muscle
flexor pollicis longus is an example of what
unipennate muscle
Rectus femoris is an example of what
Bipennate muscle
Orbicularis oris is an example of what
circular muscle
The deltoid is an example of what
Multipennate muscle
