Exam 1 Flashcards
sagittal plane
- mediolateral axis
*flexion/extension (some joints)
frontal plane
*anteroposterior axis
* abduction/adduction (some joints)
transverse plane
- vertical/longitudinal axis
- anything rotation
no plane (shoulder girdle movement)
*depression
*elevation
*protraction (abduction)
*retraction (adduction)
*upward rotation
*downward rotation
glenohumeral joint
*shoulder joint
*flexion/extension (sag)
*ab/ad (front)
*horizontal ab/ad (trans)
* in/ex rotation (trans)
humeroulnar
*elbow
*flex/ext (sag)
radioulnar
*forearm
*pronation/supination (trans)
radiocarpal
- wrist
*flex/ext (sag)
*radial/ulnar deviation (front)
1st carpometacarpal (CMC)
*thumb
*ab/ad (sag)
*flex/ext (front)
metacarpophalangeal (MCP)
*knuckles
*flex/ex (sag)
*ab/ad (front)
dist/prox interphalangeal (DIP/PIP)
*finger joints
*flex/ex (sag)
cervical/lumbar spine
*neck/lower back
*flex/ex (sag)
*R/L lateral flexion (sag)
*R/L rotation
coxafemoral
*hip
*flex/ex (sag)
*ab/ad (front)
*horizontal ad/ab (trans)
*in/ex rotation (trans)
tibiofemoral
*knee
*flex/ex (sag)
*in/ex rotation (trans)
talocrural
*ankle
*dorsifelxion/plantarflexion (sag)
subtalar
*foot movement
*inversion/eversion (front)
metatarsophalangeal (MTP)
*toe
*flex/ext (sag)
*ab/ad (front)
biomechanics
study of the mechanics as it relates to the functional and anatomical analysis of biological systems
kinematics
description of motion and includes consideration of time and space factors of a system’s motion.
EX. positions, angles, speeds, accelerations of joints, body parts or bodies
kinetics
study of forces associated with the motion of an object. internal and external
newton’s first law of motion
*law of inertia
*a body in motion tends to remain in motion at the same speed in a straight line unless acted upon by a force.
inertia
a body’s resistance to change in motion (acceleration or deceleration)
newton’s second law of motion
*law of acceleration
*a change in the acceleration of a body occurs in the same direction as the force that caused it.
f = m*a
newton’s third law of motion
*law of reaction
*for every reaction there is an equal and opposite reaction
levers
a lever (bar) rotates about an axis as a result of a force being applied to it, to cause its movement against a resistance or weight.
first class lever
axis is located between the force and the resistance
FAR
second class lever
the resistance is between the axis and the force
FRA
third class lever
the force is between the axis and the resistance
AFR
anatomical lever (bone)
lever (bar)
anatomical lever (joints)
axis
anatomical lever (muscles)
force
F x FA = R x RA, what is each component?
F = force
FA = force arm (the distance between the axis and the force)
R = resistance
RA = (the distance between the axis and resistance)
power levers
- FA is always longer than RA
*all 2nd class levers
*least common in the human body!!!
*force exerted FARTHER from axis than resistance
*advantage: LESS force needed to move BIGGER resistance
speed/ROM levers
*FA always shorter than RA
*all 3rd class levers
*most common in the human body!!!
*advantage: for a given force, speed and ROM is gained distally
*disadvantage: takes much more force to move the lever compared to the resistance
bone comp
- calcium carbonate & calcium phosphate (60%-70%)
*collagen - protein
*water (25%-30%)
*other materials: magnesium, sodium ,fluoride
cortical bone
compact
trabecular or cancellous bone
porous
what does it mean for a bone to be described as anisotropic?
the property of any material that acts differently depending on the direction in which a force is applied.
stress
load applied
stress (deformation)
change in shape
elastic region
material will return to its original shape when stress is removed
elastic limit
point where the material switches from elastic to plastic; point of no return
plastic region
some permanent deformation will occur, even if the load is removed
wolff’s law
bone adapts according to stress applied to it
*hypertrophy
*atrophy
hypertrophy
an increase in bone mass due to increased loading
*physically active individuals have higher bone density than sedentary individuals
atrophy
decrease in bone mass
differences in sexes when it comes to bone density changes with aging
WOMEN
Peak bone density: 25-28 years of age
Slow loss of BMD until 50 or menopause
Increased rate of bone loss for 5-8 years triggered by drop in estrogen
MEN
Peak bone density: 30-35 years of age
Reach higher peak bone density
Lose bone density at 2/3 the rate of women
female athlete triad
disorder eating leads to osteoporosis (nutritional deficiencies & lower body weight) and amenorrhea (absence of menstruation, hormonal disruption due to low body weight)
amenorrhea leads to osteoporosis (estrogen deficiency leads to increased bone resorption)
results of female athlete triad
- decreased bone density
- increased rate of stress fractures
- bone loss may be irreversible
example of wolff’s law
bones in a tennis player’s dominant arm may be up to 20% thicker than the bones in their non-dominant arm
diarthrodial joint
freely movable joints, synovial fluid as main structure component
enarthrodial
multiaxial ball & socket
3 degrees of freedom
circular movement - motion in all planes including rotation
EX. glenohumeral, coxafemoral
arthrodial
gliding joint
3 degrees of freedom
2 bony surfaces butt against each other
EX. sternoclavicular, tarsal joints, lumbar spine
condyloid
ellipsoidal or biaxial ball and socket
2 degrees of freedom
oval shaped condyle fits into oval shape cavity
EX. radiocarpal, 2nd - 5th metacarpophalangeal
sellar
saddle joint
2 degrees of freedom
reciprocally concave & concave articular surfaces
EX. 1st carpometacarpal
ginglymus
hinge joint - uniaxial
1 degree of freedom
articulation in only one plane
one bone surface concave, one covex
EX. humeroulnar, talocrural, tibiofemoral
trochoidal
pivot joint - uniaxial
1 degree of freedom
allows rotation only
EX. radioulnar
diarthrodial joint structure components
articular cartilage (dense, white connective tissue: shock absorption, reduces friction)
articular fibrocartilage (improves fit between bones, limits bone slip, distributes load)
ligaments
joint capsule (attaches bone to bone, completely encapsulates joint)
joint stability and mobility
resistance to dislocation and sublaxation
prevention of injury to ligaments, muscles, tendons
5 major factors to joint stability and mobility
- bony architecture
- cartilaginous structure
- ligamentous and connective tissue laxity
- muscle strength, endurance, and flexibility
- proprioception and motor control
Neuromuscular Response to Stretch - why do we want to stimulate GTOs but not Muscle Spindles?
when activated during stretching GTO inhibits muscle spindle activity within the working muscle (agonist) so a deeper stretch can be achieved
origin
more proximal landmark (vertical) more stable, less moveable landmark, more medial landmark or less stable
insertion
more distal (vertical)/more lateral (horizontal) landmark
action
the movements that happen at joints when muscles contract concentrically
agonist
prime mover at joint, muscles in charge can cause/control or prevent joint motion
antagonist
located opposite if agonist, muscle allows joint movement to occur
stabilizer
fixes/stabilizes joint so another can move, establishes firm base to allow muscles to work at distal joints
concentric contraction
shortening with tension
causing joint motion
accelerating joint/segment
movement against gravity
muscle force matches joint
eccentric contraction
lengthening with tension
controlling joint motion
decelerating joint/segment
movement with gravity
muscle force opposes motion
isometric contraction
active muscle force/tension, but no change in joint position
how does the nervous system increase or decrease the force produced by our muscles?
increase/decrease the # of motor neurons
stronger/weaker stimulus
bigger/smaller motor units
more fast twitch/slow twitch motor units
Can you explain the ACTIVE length-tension curve, and based on this curve, identify a body position that would provide maximal force for the muscles involved?
maximal ability of a muscle to develop tension/force varies depends upon the length of the muscle during contraction
generates the greatest force when at their resting (ideal) length
stretch-shortening cycle
muscles generate a more forceful concentric contraction if it is preceded by an eccentric muscle contraction
eccentric stretch prior to concentric contraction
elastic energy is stored AND muscle spindle activated
active insufficiency
when the muscle becomes shortened to the point that it cannot ACTIVELY generate force
Applies to bi/multi-articular muscles – cant ACTIVELY produce full range of motion at all joints crossed by the muscle.
passive insufficiency
an opposing muscle becomes stretched to the point where it can no longer lengthen & allow movement
A biarticular muscle becomes stretched to the point where it can no longer lengthen & allow movement.
Muscle cannot stretch enough to allow both maximal ROM at both its joints.
golgi tendon organs (GTO)
found in musculotendinous junction
responds to tension/load on the tissue
causes relaxation
muscle spindle
embedded among the muscle fibers
sensitive to the amount & rate of stretch
produces tension
myotatic reflex = “stretch” reflex: to stretch a muscle/joint
