CH 1 FAOT Flashcards
Insertion
More movable attachment
Usually distal
Origin
Attachment that moves the least
Usually proximal
Sagittal plane:
Divides body into right and left sides
Midsagittal plane in center of body (midline)
Flexion and extension movements
Frontal plane:
Coronal plane
Divides body into anterior and posterior portions
Abduction and adduction movements
Transverse plane:
Divides body into inferior and superior portions
Rotatory (rotary) movements
Axes of Motion
Joints rotate around axes of motion.
Axis is joint’s center of rotation.
Frontal axis:
Medial to lateral
Sagittal axis:
Anterior to posterior
Vertical axis:
Inferior to superior
Kinetic Chains
Cooperative, interdependent movement of segments and joints of the body
Closed-chain:
Functional movement
Proximal joints moving in relation to fixed/distal segment
Promote stabilization
Examples:
Pushing a grocery cart
Squatting to pick up a box
Open-chain:
Free movement of distal segment in space
Allows joints to move together OR independently of others
Promotes mobility
Example: conducting an orchestra
Force
Any push or pull of matter
Tensile force:
Pulling
Compressive force:
Pushing
Moment:
Turning effect of force
Ability to rotate an object around an axis
Synonymous with torque
Action:
Specific motion a muscle can generate at a joint
Synonymous with moment
Moment arm:
Lever arm
Distance from a joint to the muscle
Mechanical advantage:
Leverage
Levers:
Pulley systems
Provide mechanical advantage
Generate functional motion
First-class lever:
Exerted force and resistive force on opposite sides of axis
Examples: seesaw, human neck
Second-class lever:
Resistive force closer to
axis than exerted force
and on same side
Examples: using a
wheelbarrow, the ankle
Third-class lever:
Most common in human body
Allows for higher-velocity
movements
Joint reaction force:
Force generated within the joint in response to external forces acting upon it
Stress:
Amount of applied force per area
Example: pounds per square inch
Strain:
Amount of material displacement under
specific amount of stress
Elasticity
The ability to stretch and return to the
original shape
Young’s modulus:
Stiffness of a material
Stress-strain diagram
Elastic deformation:
Ability to return to normal shape after strain
Yield point:
Maximum stress that can be sustained before tissue failure
Plastic deformation:
Sprain
Permanent deformation of tissue but retains continuity
Biomechanics:
Examines the structure, function, and motion of the biological systems that make up a living organism
Biomechanics of Bone
Made of collagen and calcium
Cortical bone:
Greater mineral content than collagen
Shaft of long bones
Rigid support
Cancellous (spongy) bone:
Higher collagen content
Found in marrow cavity and at end of long bones
Articular (hyaline) cartilage:
Covers ends of long bones
Dense connective tissue to
absorb force between bones
Multiple layers
Ligaments:
Connect bone to bone
Joint stability
Tendons
Connect muscle to bone
Transfer force
Joint capsule:
Dense fibrous sleeve around
synovial joint
Passive stability
Contains synovial fluid
Aponeurosis:
Fibrous insertion that connects adjacent muscles
Example: aponeurosis of abdominal muscles that forms rectus sheath
Three types of muscle:
Skeletal (striated)
Cardiac (heart)
Smooth (visceral)
Biceps Brachii
Biceps brachii contraction flexes the elbow
Upper Trapezius
Acts in multiple directions
Elevates the scapula
Flexes the cervical spine laterally
Smooth Muscle
Involuntary muscle
Internal organs (intestines and
vessels)
Nonstriated
Contracts slowly and automatically
Cardiac Muscle
Forms muscular components of heart (myocardium)
Striated and in segments
Skeletal Muscle
Moves bones of skeleton
Supplies force for purposeful
movement
Striated and alternating bands of fibers
Endomysium:
Surrounds each individual muscle fiber
Perimysium
Surrounds fascicles (groups of
muscle fibers)
Epimysium
Surrounds groups of fascicles
Myofibrils
Long cylindrical strands of
contractile proteins
Sarcomeres
Contractile units of a muscle
Actin
Protein composing thin filaments
Myosin
Protein composing thick filaments
Forms central shaft of each sarcomere
Titin filaments:
Stabilizing border around myosin
Limits excursion
Z discs:
Connect actin filaments
Divide sarcomeres
Motor unit:
A single motor neuron and the muscle fibers it innervates
Commands are all-or-none
Physiological cross-sectional area (PCSA):
Area of a cross section of muscle at its widest point
PCSA and length are proportional to muscle strength
Pennate muscles:
Fibers oriented obliquely (slanted)
Multipennate, bipennate, and
unipennate
Fusiform muscles:
Fibers oriented parallel to line of force
Neuromuscular Control
A single muscle is made up of many motor units that send separate all-or- none signals to sarcomeres
Fascia
Noncontractile (passive) tissues
within the muscle
Flaccid muscle:
Results from loss of innervation to a muscle
Hypertonia:
Muscle with increased tone
Muscle spindles:
Elongated and encapsulated
structures
Within muscle fibers
Signal changes in muscle length
Protect muscles
Phasic stretch reflex:
Activates agonist muscle
Agonist muscle:
Antagonist muscle:
- Prime mover - Muscle producing desired motion
- Contrasting muscle
Golgi tendon organs:
At junction of muscle and tendon
Located in tendons
More sensitive than spindles
Slow-twitch fibers:
Type 1 fibers
Low force over a long period of time
More resistant to fatigue
Fast-twitch fibers:
Type II Fibers
Powerful contractions
Motor memory:
Learned patterns of motion
Fixators:
Synergists:
- Provide stability at origin
- Muscles that assist prime mover
Force couple:
Muscles that work together
Act in different directions to produce same motion or
stabilize a joint
Single and multiple joint muscles:
Some muscles cross 1 joint (brachialis)
Some cross multiple joints (FDP)
Example: FDP crosses wrist and MCP, PIP, and DIP and contributes to flexion
for all joints
Rectus femoris:
Two-joint muscle
Origin and insertion in same
sagittal plane
Contraction in isolation:
Hip flexion
Knee extension
Sartorius:
Two-joint muscle
Crosses multiple planes
Contraction in isolation:
Hip flexion and external rotation
Knee flexion and internal rotation
Isometric contraction:
Contraction with NO change in length
Isotonic contraction:
Contraction with change in muscle length and joint motion
Eccentric: lengthening
Concentric: shortening
Example: drinking mug of coffee
Isometric: holding mug in hand with elbow flexed to 90 degrees
Concentric: bringing mug to mouth
Eccentric: lowering mug back to table
Load rate:
How quickly force is applied to tissue
Passive insufficiency:
Inability of a muscle to elongate enough to allow a joint to move through full ROM
Example: standing and trying to touch your toes and keeping knees extended
Joint (articulation):
The connection between
two bones
Synovial, fibrous, or
cartilaginous
Synovial joints:
Mobile joints
Allow purposeful movement
Fibrous joints:
Sutures of skull
Little/no mobility
Stability
Cartilaginous joints:
Pubic symphysis
Little/no mobility
Stability
Close-pack position:
Maximal contact between articular surfaces
Maximal tension on surrounding ligaments
Example: knee in full extension
Open-pack position:
Least surface contact
Laxity of surrounding ligaments
Increased mobility of joint
Ball-and-Socket Joint
Spherical surface fits into concave depression
Most mobile
Rotates around three axes
Example: glenohumeral joint
Ellipsoid Joint
Oval-shaped convex end articulates with elliptical concave basin of another
Motion around two axes
Example: radiocarpal joint
Hinge Joint
Motion around single axis
Only flexion and extension
Collateral ligaments limiting medial
and lateral movement
Example: humeroulnar (elbow) joint
Saddle Joint
Modified ellipsoid joint
Convex and concave articulating surfaces
Motion around two axes
Example: carpometacarpal (CMC) joint of thumb
Gliding Joint
Two flat surfaces of adjacent bones
Least movement
Translation (gliding) movements
between surfaces
Example: carpal bones of the wrist
Pivot Joint
Motion around one axis
Bones rotating around another
Example: atlantoaxial joint
Osteokinematics:
Gross movement of bones
in relation to one another
Arthrokinematics:
Internal joint patterns
Involve accessory motions
that cannot be achieved by
voluntary muscle force
Translation:
Movement of joint surfaces in
same direction
Compress: joint surfaces come together
Distract: surfaces pull away
Glide: move parallel to one
another
Spin: axial rotation
Arthrokinematics
Convex-Concave Rule
Convex-on-concave surface:
Distal bone glides in opposite
direction of rotational movement
Example: wrist
Wrist flexion:
Dorsal translation of carpals
Wrist extension:
Volar translation of carpals
1.54 As the wrist flexes and extends, the carpal bones
glide in the opposite direction of joint rotation.
Distal bone glides in same direction as rotational motion
Example: MCPs
