EXAM 1 Flashcards
applied anatomy
structural kinesiology of the human movement; examination of anatomical structures of the body and their relationships with each other in regards to human movement.
- Allows us to understand what the body is capable of and its limitations.
- Used when evaluating, diagnosing, or treating a patient within healthcare jobs.
- Important for the foundation for health sciences
strengthening/improving function; maintaining optimal function
- Preventing injury
Improves health literacy and patient outcomes
Form → Function
Positive:
the shoulder joint has a round humeral head that fits into the small, shallow depression of the scapula (form) so that the humerus can rotate in many different directions, allowing for the shoulder joint to have a large range of motion (function)
Form → Function
Negative:
using poor movement mechanics (function) during weight lifting can cause the body to change shape (form) in a less favorable way that may increase the risk for an injury
Function → Form
Positive:
strength-training program; by lifting weights (function), the muscles get larger (form) and stronger to accommodate the increased weight
Function → Form
Negative:
if a person is on bed rest and not able to move around normally (function), their muscles will get smaller (form) and weaker.
Stability & mobility
inversely related (more stable = less mobile and vise versa)
Anatomical position:
Our reference position; where all anatomical locations and movements are compared/described. Many movements begin from this position.
- Standing, facing straight ahead, legs straight, feet together, arms hanging down by side, palms forward, forearms supinated.
- Allows us to know specifically where and what is being described on the body
Fundamental position
natural-feeling position; anatomical position
- relaxed, standing, arms fully relaxed, palms turned in
Prone position:
face down (ex - laying flat on your stomach)
Spine position
face up (ex - laying flat on you back)
Plane:
2 dimensional surface defined by 3 noncollinear points (not all on the same line)
- Motion occurs in a plane and about an axis
- Each plane has a corresponding axis rotation perpendicular to it
Sagittal Plane:
divides the body into right and left halves; mediolateral axis of rotation (runs side to side)
Frontal (coronal) Plane:
divides the body into anterior and posterior halves; anteroposterior axis of rotation (runs front to back)
- Abduction and adduction movements (ex- jumping jacks)
Transverse (horizontal) Plane:
divides body into superior and inferior halves; superoinferior, or longitudinal, axis of rotation (runs top to bottom)
- Rotation of the spine movements (ex- twisting, turning your head over shoulder)
- Includes supination and pronation motions
Diagonal (oblique) plane:
combines joint motions that occur between or across any of the cardinal planes; oblique (diagonal) axis of rotation.
- Can be a wide variety of movements; not considered a joint of degree of freedom
- Complex motions (ex- throwing a ball, sporting movements)
Biomechanics
the application of physics (mechanics) to the study of how living things (bio) move; involves the study of forces and their effects on the human body.
Rigid body mechanics
under the assumption that bones are rigid and therefore causing structures to not change shape when force is applied on them
Sub branch 1 - statics - studies nonmoving objects (unchanging/constant velocity)
Sub branch 2 - dynamics - studies moving objects
Kinematics & Kinetics
J body mechanics:
idea that in reality there is some deformation (change in shape) when force is applied to a structure of the body; the body is not completely rigid.
Kinematics:
description of motion; change in position
Velocity is the rate of an object’s change in position (displacement)
Three types of motion
- linear
- angular
- general
Kinetics:
the study of forces and their effects
A force is an effect that one object had on another; can be either push or pull
Force is in newton (N)
- Internal force - inside the body (ex - muscle contractions)
- External force - outside the body (ex - gravity)
- Contact force - touches the object (ex - friction)
- Non-contact force - does not touch the object (ex - gravity)
Law of inertia
an object at rest (static) will remain at rest unless a net force acts on the object to cause it to move
if an object is already moving, it will continue to move in the same direction and speed unless acted on by an external force.
Law of acceleration:
the force required to accelerate an object is directly proportional to the mass of the object.
Law of action-reaction:
for every action force there is a reaction force that is equal in magnitude and opposite in direction
the action and reaction occur at the same time
Simple machine:
a device that improves the efficiency of a force; they allows the force generated by the muscles to be magnified
Importance - makes the job/work easier and more efficient
Types found in the human body: pulley, lever, wheel & axle
Torque:
a rotational/turning force or the turning effect produced by a force that is not applied through the object’s center of mass.
Force (F) and moment arm (r) are directly proportional to torque → the more force, the greater the torque & the longer the moment arm, the greater the torque
Formula: T = Fr
Our muscles attach to our bones on the other side of the joint - so when the muscles contract, they apply the pulling force on the bones and not through the axis of rotation in the joint, generating a torque.
Lever:
rigid segment that rotates about the fixed axis (fulcrum) and a force is applied to this segment at some distance away from the axis of rotation, so that it generates a turning effect (a torque).
Our muscles contract to generate the turning force (effort) of the bony segment (rigid bar) about the joint’s axis or rotation (fulcrum) to overcome some resistance
Classes of Levers
1st class lever
axis of rotation is between the force and resistance
Good for balancing opposing forces to make steady movements
2nd class lever
the resistance is between the force and axis of rotation.
Good for magnifying the force movement so a larger resistance can be moved by a smaller force (less force exertion)
3rd class lever
the force is between the axis and the resistance
Good for amplifying speed of range of motion
Most levers in the human body are 3rd class
Uniaxial loads:
when the loads that are applied in one direction
- Tension, compression, and shear loads
Multiaxial loads:
when the direction of the forces is different to each other
- Bending, torsion, some other combination loads
Compression
a squeezing force where the ends/sides are pressed together
Produced by the pull of contracting muscles
Collinear → the forces are aligned with each other
Tension
a pulling or stretching force where the ends/sides are being pulled in opposite directions
Produced by muscles, gravity, external forces on bone
Collinear → the forces are aligned with each other
Shear
sliding or slipping force
Two noncollinear forces pointing in opposite directions from each other
Torsion
twisting force creating by opposing forces
The ends of the structure is twisted in opposite directions → create shear forces within the structure
Bending
combination of compression and tension loads
occurs when the ends of the structure are forced in the same direction that is opposite to the unsupported center of the structure
Inner, center portion in compressed and outer, center portion is tensed
Bone:
hard, dense tissue that is not completely rigid and made up of three types of bone cells: proteins (collagen, non-collagenous), minerals (calcium carbonate & calcium phosphate), and water
Calcium carbonate & calcium phosphate
provide compressive strength/stiffness; gives bones dense/hard nature (make up 60%-70%)
Collagen
provide the bones flexibility and stretchiness; keeps it from breaking under heavy loads
Water
aids nutrient transport and allows waste to leave the bone
Lever system & attachment sites for muscles (mechanical)
Simple machines → magnify force, speed, and range of motion
Bones at as a “rigid” segment lever; maybe also the resistance force
In joints, muscles can cause the bony segment to rotate about the joint, acting as the axis (fulcrum)
Muscles attach to bones & pull on attachment site when contracting, causing tensile force on the bones at attachment sites
Structure & support (mechanical)
Bones provide framework to maintain posture and withstand forces
Bones transfer forces to allow for movement
Long bones (provide structure and support) → humerus, radius, ulna, femur, tibia, fibula
Vertebrae (irregular bone) → stacked on top of each other to help body stay upright and move around
Protection (mechanical)
Bones - the densest tissue in the body that protect tissues and structures
Skull - protects brain
Vertebrae - protects the spinal cord
Ribs - protects heart, lungs, liver, etc
Bones classified as flat or irregular often serve a protective function
Mineral homeostasis & storage (physiological)
Bones act as a storehouse for essential minerals for the body like calcium, magnesium, potassium, phosphorus, sodium, and zinc
99% of body’s calcium is stored in the bones & teeth
Body withdrawn minerals (calcium) from the bones when needed (for muscle and nerve function)
Proper nutrition (high) calcium intake is important for healthy bones
Hematopoiesis (physiological)
Bones are responsible for the formation of blood cells, aka hematopoiesis
Occurs in red bone marrow in cancellous (trabecular) bone
Example of trabecular bones - vertebrae, femur, and ilium
Blood cells mature → stem cells → differentiate into erythrocytes (red blood cells), leukocytes (white blood cells), or thrombocytes (platelets)
Longitudinal vs circumferential
Endochondral vs intramembranous
Long bones:
long, rounded ended; slender middles
Provide support and structure to the body and give extremities their shape
Acts as rigid bar in a lever system and provide sites to muscle attachment
Ex - humerus, radius, ulna, fumer, tibia, fibula
Ex - hand (metacarpals), fingers, forefoot (metatarsals), and toes are all small but still considered long bones.
Short bones
small(ish), rounded/cube-like shapes
Transmit forces across joints; absorb shock
Ex - carpals (wrist); tarsals (foot)
Flat bones:
flat curved shape
Protect underlying organs/soft tissue and provide areas for attachment sites of tendons and muscle attachments
Ex - ribs, ilium, sternum, clavicle, scapula, skull
Some flat bones fuse together → irregular bones
Irregular bones:
contain a unique shape and size
Specialized functions
Ex - vertebrae, ischium, pelvis (as a whole), skull (as a whole)
Sesamoid bones:
usually small and rounded
Increase the lever arm (muscle movement) of a muscle and the mechanical efficiency of the muscle
Ex - patella (increases the amount of torque that is generated by the quadriceps muscle group - it increases the distance b/w the muscles’ line of action & the joint’s axis of rotation)
Ex - bones in the thumb (metacarpophalangeal joint)
Ex - bones in the great toe (metatarsophalangeal joint)
Joint:
act to connect the anatomical segments of the body; allow us to have complexity when performing tasks
Synarthrodial joints:
least mobile, most stable (“immovable”)
Primary function is protection and stability
Ex - tooth sockets, suture joints of skull (become immovable when on reaches adolescence)
Amphiarthrodial joints:
medium mobility; medium stability (“slightly moveable”)
Primary function is stability and transmitting forces/absorbing shock
Three subclasses:
Amphiarthrodial joints:
Three subclasses:
Syndesmosis → fibrous in nature with little motion; provides stability & transmits forces (ex - distal tibiofibular joint in lower leg)
Symphysis → cartilaginous joint where the articulating surfaces are joined by fibrocartilage, like a disc (ex - pubic symphysis of pelvis)
Synchondrosis → cartilaginous joint where articulating surfaces are joined by hyaline cartilage (ex - costochondral joints b/w ribs and sternum)
Diarthrodial joints:
most mobile, least stable (“freely moveable”)
Commonly found in extremities
Aka ~ synovial joints (due to the joint being surrounded by synovial fluid → lubricates joint & provides nutrients/removes waste)
Contains 5 components
hyaline cartilage on the articulating surfaces
synovial membrane (thin layer on deep surface of the joint capsule)
ligaments that provide support & guide the joint through its motion
blood vessels
other sensory nerves
Arthrodial (plane or gliding joint)
3 DoF, but least mobile; small range of motion
Can move in any direction, but not very far
Flat shape and the articulated surfaces glide/slide past each other in small amounts
Ex - acromioclavicular joint of shoulder girdle complex (allows forces to be transferred b/w scapula & clavicle; permits small motions to enhance joint range of motion)
Ex - joints b/w carpal bones of the wrist
Ginglymus (hinge joint)
1 DoF, uniaxial; stable > mobile; medium range of motion
Articulating surface has a round convex shape that fits into a deeper concave surface
Only permits flexion and extension; no abduction/adduction
Ex - humeroulnar joint (elbow)
Trochoidal (pivot or screw joint)
1 DoF; uniaxial; stable & mobile, medium range of motion
Permits rotation about the bony segment’s long axis
Ex - proximal radioulnar joint (near elbow) - only permits supination and pronation motions → transverse plane
Sellar (saddle joint)
2 DoF, biaxial; stable < mobile; MED-large range of motion
Articulating surfaces are concave and convex (nest together)
Prohibits axial rotation, but can produce circumduction
Less mobile than condyloid joints due to more bony contact
Ex - carpometacarpal joint of the thumb; subtalar joint in foot
Condyloid (ellipsoid or ovoid joint)
2 DoF, biaxial; more mobile, med-LARGE range of motion
Permits flexion, extension, abduction, adduction
Allows circumduction and diagonal plane motion
Articulating surfaces are concave and convex (nest together)
Prohibits axial rotation
Ex - radiocarpal joint (wrist) & metacarpophalangeal joint (knuckle) → can both flex, entend, abduct, and adduct
Enarthrodial (ball-and-socket joint)
3 DoF, multiaxial; very mobile, not very stable; large ROM
Rely on other joints, ligaments, and muscles for support
One end of the joint has a round projection (the “ball” or convex) that articulates with a depression on the adjoining bone (the “socket” or concave)
Can flex, extend, abduct, adduct, rotate internally/externally
Allows circumduction and diagonal plane motion
Ex - glenohumeral joint (shoulder) & femoroacetabular joint (hip) → both produce circumduction or other combinations of external rotation while in abduction.
Wolff’s Law of Functional Adaptation
incorporates that when a load or stress is applied to our bones, they are capable of remodeling to adapt to the stress
Remodeling
process of osteoclasts removing old bone cells in order to repair microcracks while osteoblasts create new bone cells (3-6 month cycle)
the mass and shape of bone can change based on the load
Osteoblast
builds new bone cells
Osteocyte
detects changes in load; important for communication
signals osteoclasts and osteoblasts
Osteoclast
absorb old bone (minerals go back into bloodstream)
Normal bone response to loading
Increase in bone mass due to more osteoblasts produce bone cells than osteoclasts removing them
Strength training
Normal bone response to unloading
Bones weakens over time due to more osteoclasts breaking down more bone than osteoblasts replacing it
Ex - bed rest or disuse
Pathologic bone response to loading
Pathologic bone response to unloading
Soft tissues:
cartilage, ligaments, and tendons → connective tissue that help joining two or more structures together
Cartilage
dense type of connective tissue; less dense than bone
Articular Cartilage:
reduce friction among articulating surfaces so they may move smoothly; also absorb shock from compressive and shear (sliding) forces.
Form of hyaline cartilage
Found on articulating surfaces, like the epiphyses of long bone
Doesn’t have direct blood supply/sensory nerves → damage to articular cartilage of a joint can have debilitating effects as it does not heal easily.
Fibrocartilage
provides structural support to a joint; increases surface area of the bones in contact with each other which enhances the joint’s stability; very dense
Only provides static stability
Has little to no blood supply and sensory nerves
Ex - glenoid labrum (shoulder joint), the acetabular labrum (hip joint), and the menisci (knee joint)
Ligaments:
dense, connective tissues that attaches to the bone to form a joint and function to stabilize the joint and guide it through the appropriate ranges of motion
Composed mostly of collagen proteins, elastin, and water
Not a contractile tissue → only provides static support
Little blood supply → makes it hard for them to heal
Provide important sensory information about a joint’s position in space and its changes in motion
Ex - medial collateral ligament of the knee joint (runs vertically with the bone) resists further stretching in that direction which would occur with a motion like valgus (knock knee; knees come together)
Tendons
connects muscle to bone and can stretch more than ligaments; composed of dense bundles of collagen, elastin, and water
Provides dynamic support to a joint when the muscle is contracted
Provides static support to a joint when a muscle is relaxed
Minimal blood supply; rich in sensory nervous (ex - golgi tendon organ)
They can be long and narrow or broad and flat
Aponeurosis -
Fascia:
fibrous connective tissue that holds other soft tissues like muscles and tendons together (tough; has little stretch)
Retinaculum
type of fascia that runs perpendicular to tendons (acts similar to a seat belt restraint)
Ex - extensor retinaculum of the dorsal wrist → holds the extensor tendons of the fingers in place to prevent them from bowing out away from the joint (decreasing muscle efficiency and torque production)
Synovial joint capsule:
fibrous, connective tissue that surrounds a joint to enclose the synovial fluid that is produced by the synovial membrane
provide static stability to a joint → not a contractile tissue
only found in synovial (diarthrodial) joint
stability depends on the percentage of collagen and elastin
People who are more “bendy” have higher elastin
Laxity → excess joint motion (hypermobile people)
Processes (protrusions):
serve as the attachment site for tendons, muscles, and ligaments
They stick out from the bone; may be round with a sharper edge
Ex - tibial tuberosity → the bony process on the anterior surface of the proximal tibia and serves as the attachment site for the patellar tendon
Cavities (depressions):
act to contain other structures like a muscle, tendon, nerve, or blood vessel; and can also act as the articulating surface of a joint or protect a structure
They are concave surfaces or depressions within the bone
Depth (concavity) ranges from shallow to deep
Shallow → glenoid fossa of the shoulder joint
Deep → acetabulum of the hip joint
Size ranges from small to large depressions
Small → coronoid fossa of the humerus
Large → infraspinous fossa of the scapula
Muscle:
connective tissue that connects to bones via tendons or aponeuroses
A contractile soft tissue comprised of two contractile proteins → actin & myosin
Types → skeletal, cardiac, smooth
Sarcomere - smallest unit of the muscle; contains actin (connected to Z-LINE) and myofilaments (connected to M-LINE)
Myofibrils are bundled together to form a muscle fiber which is surrounded by a connective tissue called the endomysium.
Several muscle fibers are bundled together to form a muscle fascicle which is wrapped in a connective tissue called the perimysium
Parallel Muscles
High speed movements
Relatively long and run the whole length of the muscle; this allows them to shorten quite a bit.
Muscle is aligned in the same direction as the tendon, length of the muscle-tendon-unit, and the other fibers in the muscle
Disadvantage - lower force production.
Subtypes:
Fusiform, Radiate, Sphincter, Flat, Strap
Pennate Muscles
Run at an angle to the tendons and muscle-tendon-unit which gives them a feather-like appearance
Diagonal orientation of the fibers → much shorter and less shortening capacity than parallel muscle.
More force production capacity
Arrangements:
Unipennate - only 1 direction of fibers all in the same angle
Bipennate - 2 directions of fibers that run diagonally from the tendon that runs the whole length of muscle.
Multipennate - fibers that run in more than two different directions
Agonist:
any muscle that performs joint motion when performing a shortening/concentric contraction (they are agonist of that joint motion)
Agonist motion → Joint motion that occurs during a shortening or concentric contraction
Prime movers → help the most (others just assist)
Ex: muscles of the hamstring are agonists of knee flexion; when these muscles contract concentrically, they produce knee flexion.
Antagonist:
a muscles that cause a joint motion that is the opposite of the agonist action
Located on the contralateral side of the joint from the agonist
Important for controlling/decelerating quick movements
Ex: quadriceps causes knee extension when they contract concentrically → agonists for knee extension; so the hamstrings (agonist for knee flexion) are the antagonist of knee extension
Aggregate muscle group
What does the grouping matter
How does it work with respect to the antagonist muscle group
Concentric muscle contractions
occurs when the MTU shortens (example: lifting phase of bicep curl - elbow flexor muscles shorten/produce greater force than gravity)
Attachment sites of muscles are pulled towards muscle’s center
Used to start motion or speed it up
Torque generated my muscles > torque generated by external forces
Eccentric muscle contractions
occurs when the MTU lengths (example: lowering phase of a bicep curl - elbow flexors produce less torque than force of gravity)
Actin & myosin still binding; slide past each other as muscle lengthens
Joint motion is present
Torque generated by muscles < torque from external forces
Isometric muscle contractions
static contractions (example: holding the elbow flexed at 90 deg. - elbow flexor match external torque from gravity)
Actin and myosin bind together
Joint motion does not change
Used to prevent undesired motion and stabilize
Muscle torque generated = external torque generated
Active tension
tension force generated when the muscle contracts; depends on # and size of motor units recruited
Bell shaped curve
shows muscle’s ability to produce force is related to the length of the muscle-tendon unit
Optimal resting length
length of muscle-tendon unit where there is a mex crossbridge formation between actin and myosin
Muscle can produce the highest amount of active force in the state
