Midterm Flashcards
Define open kinematic chain
Distal part of extremity is moving through space (e.g. bicep curl)
Define eccentric contraction
Muscle contraction in which the muscle lengthens as its joint moves through its ROM; muscle controls the descent of a weight or resistance against gravity; bones move away from each other as contraction occurs (e.g. setting down a glass of water)
Passive insufficiency
when a multijoint muscle is lengthened over the joints it crosses, it is too long to allow for its full ROM and its contraction ability is compromised; e.g. when the wrist is flexed, the fingers extend; when the wrist is passively extended, fingers are pulled into flexion
Shunt muscle
allows for stability; a muscle’s proximal attachment is near the joint, distal attachment further from the joint (e.g. gastrocnemius a SHUNT muscle at the knee)
Spurt muscle
designed for mobility at a joint (rotary component); typically has its origin further away from joint surface, while distal attachment is very close to the
joint that its acting at (or performing its movement); example: gastrocnemius a SPURT at the ankle
Type I muscle fiber type: red or white?
Red: presence of myoglobin for beta oxygenation
Type I muscle fiber: produces high or low tension? Contraction speed slow or fast?
Low tension, slow contraction speed
Type I fiber type: fatigues easily or not?
Type I muscle fibers are fatigue resistant
Type I muscle fibers: fiber diameter?
Small fiber diameter
Example of a muscle with a large presence of Type I “Slow Oxidative” muscle fibers?
Soleus
Which muscle fiber type relies on glycogen for its metabolic needs?
Type IIB (“fast glycolytic”)
Type IIB muscle fibers: red or white?
White (low myoglobin)
Type IIB muscle fibers: contraction speed, fatigue rate
Fast contraction speed, fatigues quickly
Type IIA fibers: what are its energy sources?
Relies on both oxygen and glycogen, has adequate myoglobin for some beta oxidation, but still contracts quickly. Fatigues at an intermediate rate compared to Type IIB and Type I fibers (best of both worlds)
What type of connective tissue is injured in a sprain?
Ligament
What type of tissue is injured in a strain?
Tendon
Describe the rotary and translatory motion in a joint when a concave surface moves on a convex surface
Rotary and translatory motions occur in the same direction
Describe the rotary and translatory motion in a joint when a convex surface moves on a concave surface
Rotary and translatory motion occurs in opposite directions
Give an example of a triaxial joint
Glenohumeral joint: can do flexion/extension, abduction/adduction, internal/external rotation
Give an example of a biaxial joint
MCPs: can do flexion/extension and abduction/adduction
Uniaxial joint: give an example
elbow: hinge, only does flexion and extension
what is a complex joint?
a simple or compound joint that contains a disc or a meniscus (TMJ, knee)
what is a compound joint?
joint with more than 2 bones involved (e.g. elbow, wrist
simple joint
only 2 bones involved; e.g. glenohumeral (also complex!), MCPs
Diarthrodial joint
freely moveable, synovial joint
Amphiarthrodial joint
Small amount of joint play, e.g. pubic symphysis, sternocostal
Motion along the x-axis occurs on which plane?
sagittal
AC joint motions
Internal (medial)/external (lateral) rotation; A/P tipping (tilting); upward/downward rotation
AC joint upward/downward rotation: what is the reference point on the scapula? What plane/axis?
Glenoid fossa: tilts up during upward rotation, down on downward rotation; motion limited by coracoclavicular ligaments; Occurs along z axis, frontal plane
AC A/P tipping: function; occurs during what motion of the scapulothoracic joint?
AC anterior/posterior tipping: of the scapula in relation to the clavicle; keeps the scapula contoured to the thorax; occurs during scapular elevation (anterior tipping) and depression (posterior tipping)
AC joint medial/lateral rotation: which axis? What does this motion do in the glenoid fossa and along the thorax? What occurs in relation to the clavicle?
Y-axis; transverse plane; brings glenoid fossa anteromedially, posterolaterally; maintains contact of scapula with horizontal curvature of thorax as clavicle protracts and retracts
Motion along the Z-axis occurs on which plane?
Frontal plane
Motion along the Y-axis occurs on which plane?
Transverse plane
Define/describe active insufficiency
Occurs when full ROM is attempted simultaneously at all joints crossed by a multijoint muscle, producing a decrease in torque available; muscle is shortened the joints it crosses (e.g. wrist flexed, fingers less able to make a strong fist)
Rotary motion
Direction of whole bone/segment
Translatory motion
Motion directly at joint surface
2 types of cartilage commonly found in joints
Fibrocartilage (discs, symphyses); hyaline (covering humeral head, etc)
Role of retinaculum
Binds down tendons
Cortical bone
Compact, outer layer; dense, stores and releases Ca2+
Cancellous bone
Spongy bone/trabecular; site of hematopoiesis, contains red bone marrow
Trabelculae
Calcified collagen, main component of cancellous bone
osteoblasts
Build up bone
osteoclasts
break down bone
epimysium
Connective tissue that covers an entire muscle, continuous with deep fascia
endomysium
surrounds individual muscle fibers
perimysium
surrounds fascicles
Fascicles
Bundles of muscle fibers surrounded by perimysium
Fusiform muscle
Long fibers running parallel to the line of pull and parallel to the long axis of the muscle; aka longitudinal muscle; e.g. sartorius, rectus abdominus
Pennate muscle fibers
Run obliquely to longitudinal axis of muscle
Fusiform vs. pennate muscles: which fiber arrangement allows for more muscle fibers? What does this mean for tension production?
Pennate muscles contain more fibers, can therefore produce greater tension
which muscle fiber arrangement is better for joint excursion/ROM?
Longitudinal/fusiform muscle fibers
Define torque
Torque= force x distance
-tendency of a force to create rotation or motion around an axis
Center of mass (COM)
balance point around which the effects of gravity are concentrated
Class I lever, example
Seesaw; axis is between the internal force and the external force. Example: AO joint
Class II lever, example
Wheel barrow; axis, external load, internal force; example: MTP joint, standing up on tip toes. Least common lever type in the body
Class III lever, example
Bicep curl; axis, internal force, external load; very common in the body
External torque definition
Text= (Weight of limb X COM) + (Weight of external load X Distance of load from axis)
Text = (R X ra) + (W X Wa)
Internal torque definition
Tint=Rotary force X Distance of insertion from axis
Tint= Fr X fa
Tint=Text
Name 4 joints of the shoulder girdle
Scapulothoracic, sternoclavicular, acromioclavicular, glenohumeral
Motions of the scapulothoracic joint plus reference point:
abduction/adduction (protraction/retraction), elevation/depression, upward/downward rotation (glenoid fossa reference)
Motions of the SC joint (use clavicle as reference)
elevation/depression, protraction/retraction, A/P rotation of the clavicle
What type of joint is the SC joint?
Saddle shaped, plane synovial joint; complex (contains a disk), triaxial
SC joint: elevation/depression of clavicle. what axis/plane?
Z axis, frontal plane
SC/clavicular elevation and depression: normal ROM?
~45 deg. elevation; ~15 deg. depression
SC j. clavicular elevation/depression: clavicle and manubrium surface convex or concave?
Clavicle surface convex, moves on concave manubrium
SC j. protraction/retraction: plane and axis?
y axis; transverse plane
SC j. protraction/retraction: joint surface concave/convex?
Clavicle concave, manubrium convex (opposite of elevation/depression–SADDLE joint)
SC protraction/retraction ROM:
~15-20 deg. protraction; ~20-30 deg retraction
SC Anterior/Posterior rotation: axis/plane?
x axis, sagittal plane
SC A/P rotation: ROM
Posterior rotation (aka upward rotation, backward rotation): up to 50 deg; Anterior rotation: >10 deg (return to neutral from posterior rotation)
Ligaments supporting the SC joint:
Interclavicular, anterior sternoclavicular, costoclavicular ligs (A/P); ***also subclavian muslce provides stability
What ligaments stabilize the AC joint?
Superior/inferior AC ligament; Coracoclavicular ligament (includes conoid and trapezoid)
Raising the arm produces passive tension on which AC ligament?
Conoid
Upward/downward rotation of the scapula: which shoulder joint(s) involved?
SC joint (clavicular elevation/dep, upward/downward rotation), AC joint upward/downward rotation, up/down rotation of the scapulothoracic
Elevation/depression of scapula: which joint(s) involved?
SC joint elev/dep, AC joint A/P tipping, AC joint rotation
Protraction/retraction of scapula: joint(s) involved?
scapulothoracic abd/add, SC joint protraction/retraction, AC joint rotation (med/lat)
Glenohumeral joint: type of joint
Triaxial, ball and socket synovial, complex (simple) joint
Normal ROM glenohumeral flexion/extension
~180 deg flex, ~40-60 deg extension (sagittal plane x axis)
Motions of the GH joint
Flexion/extension, abduction/adduction, int/ext rotation, horizontal abd/add
Ligaments supporting the GH joint
sup, middle, inf GH ligaments, coracohumeral lig, plus supraspinatus tendon
GH horizontal abd/add: normal ROM
Horizontal abd ~45 deg; add ~130 deg
in full abduction at the shoulder, how much ROM is attributed to the GH joint, how much to other shoulder girdle (i.e. scapular) joints?
120 degree GH, 60 degrees scapular
in the first 90 degrees of abduction at the shoulder, how many degrees are done by the GH joint, how much is done by the SC joint, how much by AC j?
60 degrees GH joint, 25 degrees by SC joint, 5 degrees AC joint
from 90-180 of abduction at the shoulder, what is the distribution of ROM for GH j, SC and AC jj?
60 degrees GH, 25 degrees AC, 5 degrees SC
Arm abduction/elevation: accessory motions
scapular abduction, upward rotation, medial rotation (winging), posterior tipping IS THIS RIGHT???
What structures make up the coracoacromial arch?
Coracoid process, acromion, coracoacromial ligament, arches over humeral head; contains subacromial bursa, supraspinatus-leads to RC tendons, can be impinged, worn down
How to test upper traps
Shoulder shrug against resistance
Overall function of traps for shoulder girdle
Holds up shoulder girdle against gravity, assists in some scapular movements (upward rotation)
Testing the middle traps
squeeze shoulder blades together
Testing lower traps
Abduct arm 140 degrees, extend shoulder
What muscles are involved in the synergy that allows scapular upward rotation?
Upper traps (lifts acromion+clavicle), lower traps (lowers root of scapular spine), serratus anterior (protracts scapula along thorax wall)
testing the rhomboids
place hand behind back, retract shoulder blade (adduct)
rhomboids-action
adducts, downward rotation of scap
levator scapula-action
elevation, downward rotation
pec minor-action at scapula
depression, downward rotation
coracobrachialis-actions
flexion, adduction
supraspinatus-actions
primary abductor, stabilizes GH, steers hum head in fl fossa as arm raises (convex on concave)
which part of the deltoid does external rotation?
posterior delt
Infraspinatus actions
Good external rotator of arm, pulls humeral head down during arm elevation
In full arm abduction, which direction of humeral rotation is important for full ROM?
External rotation rotates greater tuberosity out of the way to clear the acromial shelf
Teres minor: actions
external rotation, some adduction/abduction
Rotator cuff external rotators:
infraspinatus, teres minor, plus posterior delt
Rotator cuff internal rotators:
subscapularis plus anterior delt plus teres major plus lats
Lats-actions
adduction, internal rotation, extension, scapular depression and downward rotation
pec major-actions
internal rotation (biciptal groove attachment), weak flexor (clavicular head), horizontal adduction, scapular depression (sternal head), protraction (both heads, but steral moreso)
Synergy: levator scapula, rhomboids, pec minor
Create scapular downward rotation
levator scap: pulls root of scap spine upward
rhomboids: pull medial border of scapula upward, tilting GH joint down
pec minor: pulls coracoid down, which is lateral to axis, supports downward rotation
Which synergy assists in the translatory motion of the humeral head in the GH joint during arm abduction?
Deltoids+rotator cuff
Which muscles act synergistically to prevent the shoulder from being pulled DOWN during abduction and flexion (
Delts+upper traps
Rhomboid + teres major synergy
for teres major to act as an extensor and adductor of the distal humeral attachment, the proximal attachment at the scapula must be stabilized because it is lighter than the distal attachment; the rhomboids (downward scap rotators) thus fix the scapula (prevent it from rotating upward) as the teres major contracts in order to move the heavier humerus
elbow-joint type, movements
uniaxial, hinge, flexion/extension
elbow ROM
flexion ~140-150 deg; neutral 0 deg; hyperextension possible
Trochlear ridge of ulna articulates with the ______________ of the humerus
trochlear groove
the coronoid process of the ulna articulates with the ___________________ at the limit of elbow flexion
coronoid fossa
During elbow flexion, the head of the radius fits into the ________________, which is designed to receive the head of the radius during elbow flexion. This groove is just proximal to the capitulum.
radial fossa
What bony structure fits into the capitulotrochlear groove?
The rim of the radial head!
During elbow flexion, the radius gets (closer/further) away to the humerus
It gets closer: it slides around capitulum and articulates with the radial fossa
During full elbow extension, what does the olecranon process articulate with on the humerus?
Olecranon fossa
Medial (ulnar)collateral ligament resists what type of forces?
Valgus forces (medially directed)
The lateral collateral ligament resists what type of forces?
Varus forces (laterally directed)
What are the articulating surfaces of the proximal radial ulnar joint?
Radial head-radial notch (ulna)
What are the articulating surfaces of the distal radioulnar joint?
Ulnar head-sigmoid ulnar notch (radius)
During pronation/supination of the arm, which bone moves? Which bone doesn’t?
Radius moves over the ulna, crossing over it during pronation. Ulna moves very little.
What bony structures in the elbow joint limit extreme flexion of the elbow?
approximation of the coronoid process with coronoid fossa; rim of radial head in radial fossa
Brachialis: shunt or spurt? Why?
Spurt: distal attachment lies close to the elbow joint (inserts on the ulna); proximal attachment lies further away, at mid humerus
Biceps brachii flex and __________ the arm
Supinate: distally attach at the radial tuberosity, can supinate and flex the arm.
Position of active insuffiency for biceps brachii?
Shoulder flexed, elbow flexed
Brachioradialis: shunt or spurt at the elbow?
Shunt muscle (stabilizing elbow joint): proximal attachment is close to the elbow joint (lateral supracondylar ridge), distal attachment all the way down at the radial styloid process.
Triceps passive insufficiency position:
Shoulder extended, elbow flexed (same as biceps brachii active insufficiency)
Which ligament encircles the rim of the radial head and stabilizes the proximal radioulnar joint?
Annular ligament
What is the primary pronator of the arm?
Pronator quadratus
How can the supinator be tested?
Fully extend the arm to inhibit the biceps from assisting in supination
Which action is stronger: pronation or supination of the arm?
Supination! Assistance from biceps
What muscle synergy helps prevent shoulder flexion during elbow flexion?
Posterior deltoid is active during elbow flexion to prevent shoulder flexion
Role of triceps in a pushup: when do they act concentrically, when do they act eccentrically?
Upon descent during a pushup, triceps act eccentrically to control elbow flexion; during the push UP, triceps act concentrically to extend the elbow
Stabilizing synergy: when biceps are acting as a supinator, what other muscles prevent flexion of the elbow?
Triceps
Anconeus: assists in elbow extension and stabilizes during what movements?
Pronation and supination
Wrist joint characteristics
Complex, compound; biaxial
2 components of the wrist joing
radiocarpal, midcarpal
Does the wrist joint have greater radial deviation or ulnar deviation capabilities?
Ulnar deviation ~30-35 deg (rad. dev up to 25 deg)
Does the wrist have greater flexion or extension?
Flexion ~80-90 degrees (extension ~70-80 degrees)
Which part of the wrist joint brings wrist from full flexion to neutral?
Midcarpal
What part of the wrist joint brings wrist from neutral to ~45 degrees of extension?
Distal carpal + scaphoid
Which component of the wrist joint brings the wrist from 45 degrees of extension to full extension?
Radiocarpal
What structures make up the radiocarpal joint?
Radius, radial ulnar disc, scaphoid, lunate, triquetrum, NOT ULNA
What structures make up the midcarpal joint?
proximal row of carpals-scaphoid, lunate, triquetrum; articulate with the distal row-trapezium, trapezoid, capitate, hamate
In the sagittal plane, what does the scaphoid do during radial deviation?
flexion
In the sagittal plane, what does the scaphoid do during ulnar deviation?
extension
In the frontal plane, what do the proximal and distal carpal rows do during ulnar deviation?
During ulnar deviation, the proximal row of carpal bones move radially, but the distal row moves ulnarly.
In the frontal plane, describe the movement of the proximal and distal row of carpals during radial deviation
During radial deviation, the proximal carpals move ulnarly and the distal row moves radially
What are the primary wrist flexors?
Flexor carpi ulnaris, flexor carpi radialis, palmaris longus
T/F: Flexor digitorum superficialis crosses the elbow joint and runs to the middle phalanges of 4 digits (no thumb)
TRUE! The humeral head originates at the medial epicondyle/common flexor origin). The radial head starts at the radius.
T/F The tendon of the flexor carpi radialis can be felt just laterally to the radial pulse.
False! The FCR tendon attaches to the base of the 2nd metacarpal, so it is palpable just medial (ulnarly) to the radial pulse.
FCR flexes and _______ ________ the wrist.
radially deviates
What are the actions of the FCU?
Wrist flexion, ulnar deviation (distally attaches to the pisiform, hook of hamate, 5th cetacarpal)
How can the flexor pollicus longus be palpated?
Flex thumb DIP against resistance, tendon palpable
What motions can occur with FPL activity?
Wrist flexion, radial deviation
Which muscle makes up the “basement” of the snuff box?
Abductor pollicus longus
What tendon comprises the “roof” of the snuff box?
Extensor pollicus longus
Which muscle makes up the “floor” of the snuff box?
Extensor pollicus brevis
What are the primary wrist extensors?
Extensor carpi radialis longus (also radial deviator), extensor carpi radialis brevis (weak rad. dev), extensor carpi ulnaris (also ulnar deviator)
T/F: the extensor carpi radialis longus crosses 2 joints.
TRUE! Crosses elbow and wrist (lateral supracondylar ridge to base of 2nd metacarpal)
T/F: the extensor carpi ulnaris crosses 2 joints
TRUE! Lateral epicondyle of humerus->posterior border of ulna->dorsal aspect of 5th metacarpal
What is the role of the wrist extensors with respect to finger flexion/wrist flexion?
The wrist extensors prevent wrist flexion during finger flexion; stabilize wrist for finger dexterity
What stabilizing synergy prevents excessive radial deviation during thumb muscle activation?
Extensor carpi ulnaris and flexor carpi ulnaris (the primary ulnar deviators!) stabilize and prevent radial deviation
T/F: all of the muscles that make up the snuff box are considered to be primary radial deviators
TRUE
What muscles contribute to “cupping” the carpometacarpal (CMC) joint?
FCU, FCR, FDP, FDS
What muscles contribute to “uncupping” at the carpometacarpal joint?
ECU, ECRL, ECRB, ED
Define carpometacarpal joint
Distal row of carpal bones articulating with the metacarpals
The 1st metacarpal articulates with which carpal bone?
trapezium
The trapezoid articulates with which metacarpal?
2nd
Which carpal bone articulates with the 3rd metacarpal?
capitate
The hamate articulates with which metacarpal(s)?
4th and 5th
Which CMC joint is the most mobile?
1st metacarpal/trapezium
Which CMC is the second most mobile?
4th/5th metacarpals/hamate
What type of joints are the 2nd-5th metacarpophalangeals?
condyloid! biaxial!
What type of joint is the 1st MCP?
Hinge, uniaxial (flexion/extension)
In the thumb, at what joint does abduction and adduction occur?
Carpometacarpal joint, NOT MCP!
In MCP joints, is the phalanx concave or convex? Is the metacarpal concave or convex? Describe the arthrokinematics of this joint relationship
Metacarpal head CONVEX; phalanx CONCAVE; rotary and translatory motions occur in the same direction
In finger abd/adduction, what is the point of reference?
3rd digit
How do you describe the abduction/adduction of the 3rd digit?
Radial abduction/ulnar abduction
Why is it nearly impossible to abd/add the fingers during MCP flexion?
the joint is in its close packed position, no room for abduction
Does the 2nd or 4th MCP exhibit greater flexion?
The 4th: ulnar side of the MCPs have more flexion than the radial side
PIP/DIP joint type
Hinge, uniaxial
PIP ROM:
~100-130 degrees flexion (digits 2+3 have less than 3+4)
DIP ROM
flexion ~80-90 degrees, can hyperextend ~10 degrees
Thumb IP ROM
~80 degrees flexion, 10 degrees extension
What is the route of the lumbricals?
Cross MCP jj. palmarly, pass obliquely to lateral side of extensor hood on proximal phalanges 2-5; allows MCP flexion, IP extension
Which intrinsic hand muscles abduct the fingers?
Dorsal interossei
Which intrinsic hand muscles adduct the fingers?
Palmar interossei
T/F: Extensor digitorum can extend both the wrist and the fingers without the help of the intrinsic hand muscles
FALSE! Extensor digitorum can only extend primarily the proximal phalanges. The intrinsics (lumbricals and dorsal interossei) complete the extension of the DIP
What movements are possible at the 1st CMC joint (thumb)?
Flexion/extension, abduction/adduction, axial rotation toward/away from palm
Define power grip
A forceful act resulting in flexion at all finger joints; thumb may act as a stabilizer to the object and the object is generally fixed against the palm.
Types of power grip:
Cylindrical grip (glass of water), spherical grip (ball), hook grip (holding a suitcase handle), lateral prehension (holding an index card between fingers)
Define precision handling
Palm generally not used; skillful placement of an object between the fingers or between the thumb and finger.
Types of precision handling
pad-to-pad (using tweezers), tip-to-tip (some styles of writing), pad-to-side (using a key)
MCP 2-5 heads are concave/convex?
Convex
Cylindrical grasp: what muscles are probably most active?
FDS, FDP (finger flexion); thumb abductors plus adductor pollicis to stabilize thumb
What muscles would be most active in a spherical grasp?
FDS, FDP; extrinsic thumb flexors (FPL, APL), interossei (both the abductors and adductors)
Hook grasp: what muscles most active?
no thumb, mostly FDS, FDP
What is a “jaw chuck” grasp?
A style of pad-to-pad precision grasp; ex)Holding a pencil: using thumb, pressing object against 1 or 2 other digits.
Muscles active in jaw chuck grasp?
Intrinsic thenar and hypothenars: OPB, FPB, AbdPB, lumbricals, interossei
