Quiz 2 Flashcards
what is an isometric exercise?
contraction with no length change
what is a concentric exercise?
contraction against gravity with the muscle getting shorter
is concentric contraction positive or negative work?
positive work bc motion is produced by the muscle
what is an eccentric exercise?
contraction with gravity where the muscle is getting longer
is eccentric contraction positive or negative work?
negative work bc the external force is responsible for motion done by the muscle
what is an isokinetic exercise?
constant rate of movement
zero acceleration
usually can’t generate this contraction and have to use a machine
in isometrics, muscle torque is _____ the load torque
=
in concentrics, muscle torque is ____ the load torque
>
in eccentrics, muscle torque is ____ the load torque
<
predicting muscles function is simple when….
proximal attachment is stabilized
distal attachment moves towards proximal (often OKC)
distal segment moves against gravity (concentric)
acceleration activity
3rd class lever
muscle provides a moving force
muscles often function as follows:
proximal attachments moves towards distal attachment (often CKC)
distal segment motion may be assisted by gravity (eccentric)
deceleration activity
2nd class lever
muscle provides a resistance force
what are type 1 muscle fibers
slow twitch
fatigue resistant
small amount of forces
what are type 2a fibers?
fast twitch
oxidative
mix of 1 and 2b
what are type 2b muscles fibers?
fast twitch
glycolytic
least fatigue resistance
good for explosive movements and large force generations
how do muscles fibers change as you age?
there is a preferential loss of type 2 fibers
what are postural muscles?
muscles that maintain posture
what type of fibers are postural muscles?
type 1
what muscles are postural muscles?
trunk extensors, abdominal muscles, hamstrings, quads, glutes, cervical flexors, delts, soleus
what are phasic muscles
muscles that contract rapidly and generate a lot of fibers
what type of fiber are phasic muscles?
type 2
what muscles are phasic muscles?
gastrocs, biceps, upper extremity flexors
what is an agonist?
prime mover
what is an antagonist?
muscle that produces opposite actions of the prime mover and resist movement if activated
usually reciprocal inhibition of antagonist or co-contraction
what is a synergist muscle?
muscles that helps the agonist action
what are the 2 subcategories of synergists?
stabilizers and neutralizers
what are stabilizers?
muscles that stabilize the proximal jt for distal jt movement
usually act isometrically
what are neutralizers
muscles that stop unwanted movement of the agonist
what is co-contraction?
muscles contracting together to stabilize a limb so that the distal movement can occur
what are the 8 factors that affect muscles strength/performance?
- muscle size
- architecture of muscle fibers
- passive components of the muscle
- physiological length of the muscles/length-tension relationship of the muscle
- moment arm length
- speed of muscle contraction
- active tension
- age and gender
how does muscle size affect muscle strength/performance?
shorter=stability
longer=mobility
hypertrophy adds fibers in parallel making a wider stronger muscle
atrophy causes loss of muscles bulk and strength
what are fusiform muscles?
fascicles are long and parallel
limited force generating capabilities
very good at shortening muscles distance
what is an example of a fusiform muscles in the body?
sartorius
what are pennate muscles?
parallel fibers attach at oblique angle to a common tendon
shorter muscles
greater force producing capabilities
what is a uni-pennate muscle?
one group of fibers attaching to 1 common tendon
what is a bi-pennate muscle?
2 groups of fibers heading to one common tendon
what is a multipennate muscle?
more than 2 groups of fibers on multiple tendons
what are some examples of bi-pennate muscles in the body?
gastrocs, rectus femoris, dorsal head of interossei of hands
what is an example of a multi-pennate muscle in the body?
the deltoids
do fusiform or pennate muscles have greater force generating capabilities?
pennate muscles
what are the passive components of muscles?
parallel elastic component
length tension relationship
series elastic component
what is the parallel elastic component of muscle?
passive components are arranged in parallel to muscle fibers that passively shorten and lengthen with the muscle
what are the fascicle layers?
epimesium, perimesium, and endomysium
what is the length tension relationship component of muscles?
the greatest tension for optimal force generation is b/w 80-120% of resting muscle length
passive tension only exists past 100% resting length, so a slightly stretches muscles will have the greatest force producing capabilities
t/f: passive tension only exists past 100% resting length
true!
what is the series elastic component of muscles?
the arrangement is tendon-muscle-tendon attached in series
tendons don’t contract, they just get pulled on when muscle length changes
what is the moment arm component of muscles?
100% muscles force rotates the jt when the insertion is parallel to the bone segment
angle of insertion influences torque
more extension=mostly compression and some rotation
lots of flexion=little rotation, mostly distraction
more than 90 deg, less than 120 deg=50/50 rotation/distraction
what is age and gender component of muscle?
both girls and boys have similar grip strength until puberty, when boys tend to gain greater grip strength
peak 20-30 followed by gradual decrease in both sexes
has a lot to do with hormones
what is functional excursion?
muscles having a sufficient amount of length to complete activities
70% of resting muscles length is the muscle’s ability to ____
shorten
what are the 2 components of muscles excursion?
active and passive insufficiency
what is active insufficiency?
the inability of a multi joint muscle to shorten simulataneously at all jts.
what is an example of active insufficiency in the body?
weak grip resulting from wrist and fingers flexion bc the muscles are maximally shortened
active insufficiency position for 1 muscle will put the antagonist in _____ _______ position
passive insufficiency
why can’t muscles contract anymore in active insufficiency?
there’s no room to create more cross bridges
what is passive insufficiency?
inability of a multijoint muscle to lengthen simultaneously at all joints
why can’t muscles lengthen anymore in passive insufficiency?
bc there is no overlap b/w actin and myosin
what is an example of passive insufficiency in the body?
when you can’t extend your fingers as much with the wrist also extended
when a muscle is in passive insufficiency, the antagonist is in _____ ______
active insufficiency
muscle end range is …
passive
muscle function is …
active
what is a tenodesis grip?
when the wrist is fully flexed, the fingers extend and when the wrist is fully extended the fingers flex
this can be used when there is wrist function available but not finger function in order to grip things
what is the function of the shoulder complex?
to place and move the UE in space for function
what are the bones of the shoulder complex?
sternum, scapula, clavicle, and humerus
what are the 4 joints of the shoulder complex?
SC joint
AC joint
GH joint
sternothoracic joint
what is the only bony attachment of the UE to the axial skeleton?
the SC joint
the long axis of the clavicle is about ____deg to the frontal plane
20
why is the clavicle 20 deg to the frontal plane?
the angle increased GH mobility to permit greater reaching and climbing motion
what is the functional significance of the scapula?
placement of the glenoid fossa
mechanical advantages
arm elevation
what is the function of the glenoid fossa labrum?
to deepen the concave surface
increase congruency and contact area to decrease pressure and improved shock absorption
what is the function of bursa?
cushion, lubrication, decrease friction, smoother scap movement
what kind of joint is the SC joint?
a sellar (saddle) jt with 3 DF
is the SC jt a synovial joint?
yes
t/f: almost all US motion impact the SC jt
true
what are the 2 ways the SC is divided?
b/w the disc and clavicle
b/w the disc and sternum
describe the surfaces of the SC joint
both surfaces have a concave and a convex portion
the manubrium is convex on the ____ axis and concave on the _____ axis
AP, vertical
how many DF does the SC joint have?
3
what are the motions of the SC joint?
elevation-depression (frontal plane, z axis)
protraction-retraction
(transverse plane, y axis)
transverse rotation
(long axis)
describe the roll and glide of the SC joint with elevation
superior roll
inferior glide
(opposite directions bc the convex clavicle is moving on the concave manubrium
describe the roll and glide for the SC joint with depression
inferior roll
superior glide
(opposite directions bc the convex clavicle is moving on the concave manubrium)
describe the roll and glide of the SC joint with retraction
posterior roll and glide
(same direction bc the concave clavicle is moving on the convex sternum
retraction is limited by the ____ SC ligament
anterior
protraction is limited by the ____ SC ligament
posterior
describe the roll and glide of the SC joint with protraction
anterior roll and glide
what type of cartilage is the articular disc of the SC joint?
hyaline
what is the function of the articular disc of the SC joint?
shock absorption, congruency, prevents clavicle from sliding over the manubrium
the anterior and posterior SC ligaments protect against what direction of stresses?
anterior-posterior
what motions do the anterior and posterior SC ligaments restrict?
protraction and retraction
what is the function of the interclavicular SC ligament?
it prevents upward displacement
what is the function of the costoclavicular ligament?
to restrict elevation, transverse and AP rotation
what muscles stabilize the SC joint?
sternothyroid, sternohyoid, SCM, and subclavius muscles
what is the role of the SCM muscle?
it reinforces the SC jt capsule and ligaments
SCM
O: sternal head and clavicular head
I: mastoid process
A: shoulder elevation, anterior flexion, lateral flexion, and rotation in the opposite direction
N: accessory nerve
what is torticollis?
paralysis/tightness of the SCM due to womb positioning or difficulty in labor usually with no neuro symptoms
t/f: the shape of the clavicle and rotation improves scapular elevation
true!
the clavicle rotates _____ when elevating the arm over 90 deg of shoulder elevation
posteriorly
what kind of jt is the AC jt?
a plane synovial joint
t/f: there is not much movement at the AC joint
true
what kind of cartilage lines the AC joint?
fibrocartilage
the acromial end of the AC jt faces ____ and _____
medially, superiorly
the clavicular end of the AC jt faces ____ and ____
laterally, inferiorly
what is the function of the AC jt?
position modifier/fine tuner of GH movement
how many DF does the AC jt have?
3
what are the osteokinematics motions of the AC jt?
elevation-depression
protraction-retraction
upward-downward rotation
what is the function of the coracoclavicular ligaments?
prevent superior dislocation of the AC jt
produce rotation of the clavicle and limits rotation of the scap
what are the 2 coracoclavicular ligaments?
trapezoid (lateral) and coracoid (medial) ligaments
what muscles stabilize the AC jt?
deltoids and upper trap
t/f: the scapulothoracic jt is not an anatomic jt
true
what are the functions of the scapulothoracic jt?
increase shoulder ROM
maintain favorable length-tension relationship for the delts above 90 deg to optimize shoulder stability
provide GH stability by maintaining jt alignment
injury prevention through shock absorption
permit elevation of the body in CKC
what are the osteokinematic motions of the scapulothoracic jt?
scapular elevation-depression
scapular protraction-retraction
scapular upward-downward rotation
scapular tilt
t/f: the scapula gets more elevation motion than depression motion?
true
does the scapula get more protraction or retraction?
protraction
where is the scapular plane?
about 40 deg anterior to the frontal plane
with upward rotation, what are the SC and AC jt motions?
SC-elevation
AC-rotate upward and anterior
anterior scapular tilt creates what SC and AC jt motions?
anterior rotation
posterior scapular tilt creates what SC and AC jt motions?
posterior rotation
what are the muscles stabilizing the scapula?
traps, levator scap, rhomboids, serratus anterior, pec minor
upper trap
O: occiput, ligament nuchae
I: outer 1/3 clavicle, acromion
A: scapular elevation and upward rotation
N: accessory
middle trap
O: C7-T3 spinous processes
I: scapular spine
A: scapular retraction
N: accessory
lower trap
O: mid-low thoracic spinous processes
I: base of scapular spine
A: scapular depression and upward rotation
N: accessory
levator scapula
O: C1-4 transverse processes
I: vertebral border of the scapula b/w the spine and superior angle
A: scapular elevation and downward rotation
N: dorsal scapular
rhomboids
O: C7-T5 spinous processes
I: vertebral border scapula b/w spine and inferior angle
A: scapular retraction and downward rotation
N: dorsal scapular
serratus anterior
O: lateral surface of 1st 8 ribs
I: anterior surface of vertebral border of scap
A: scapular protraction and upward rotation
N: long thoracic
what muscle is weakened in scapular winging?
the serratus anterior
what is the force couple of upward scapular rotation?
the upper trap pulls up on the lateral margin of the scap
the lower trap pulls downward on the scap spine
the serratus anterior pulls up on the inferior angle/lateral margin of the scap
pec minor
O: anterior surface of ribs 3-5
I: coracoid process
A: scapular depression, downward rotation, and scapular tilt
N: medial pectoral
what is the force couple of downward rotation of the scapula?
the levator scap pull up on the medial superior border of the scap
the rhomboids pulls up on the medial inferior border of the scapula
the pec minor pulls down on the lateral border of the scapula
what are the prime movers of scapular elevation?
upper trap
levator scap
rhomboids
what are the prime movers of scapular depression?
lower trap
pec minor
lower serratus anterior
what are the prime movers of scapular protraction?
serratus anterior
pec minor
what are the prime movers of scapular upward rotation?
upper trap
lower trap
serratus anterior
what are the prime movers of scapular downward rotation?
levator scap
rhomboids
pec minor
what is the prime mover of scapular tilt?
pec minor
what are the prime movers of scapular retraction?
mid trap
rhomboids
what kind of jt is the GH jt?
synovial ball and socket jt
the GH joint is mostly for providing mobility or stability?
mobility
how many DF does the GH jt have?
3
what are the osteokinematic motions of the GH jt?
flexion-extension
(sag, x)
abduction-adduction
(front, z)
medial-lateral rotation
(tran, y)
horizontal abduction-adduction
(tran, y)
does the humeral head face slightly forward or backward?
backward (retroverted)
how does the humerus face?
retroverted, up, and medially
what is the role of the rostral/caudal rotation of the humerus?
so the humerus can resist greater twisting forces
puts the elbow in the appropriate angle
what is the function of the soft tissue at the GH jt?
to put the hand where it needs to be
what are the ligaments of the GH jt?
glenohumeral
coracohumeral
coracoacromial
what is the significance of the coracoacromial arch and ligament?
it provides a very small space for tendons including the rotator cuff tendons to pass through
it has an increased tendency to get swollen and causes subacromial impingement
how many bursae are at the GH joint?
8
what is the function of negative pressure at the GH jt?
it keeps the head of the humerus in the glenoid fossa in addition to the muscle activity
what is a location of weakness in the GH j capsule?
the foramen of Weitbrecht
what is the foramen of Weitbrecht?
an area of weakness of the GH capsule and frequent site of anterior dislocation of the humerus
what is normal flexion at the GH jt?
180 deg
what is normal extension at the GH jt?
65 deg (passive)
80 deg (active)
what is the normal abduction at the GH jt?
180 deg
what is normal internal rotation at the GH jt?
70 deg
what is normal external rotation at the GH jt?
90 deg
what is OPP of the GH jt?
20-30 deg horizontal abduction
55 deg flexion
what is CPP of the GH jt?
full abduction
full lateral rotation
what OPP of the SC jt?
arm resting at the side
what is CPP of the SC jt?
arm in full elevation
what is OPP of the AC jt?
arm resting at the side
what is CPP of the AC jt?
arm at 90 deg abduction
what is scapulohumeral rhythm?
for every 1 degree of scap motion there is 2 degrees of GH motion after 30 degrees of abduction
when does scapular motion kick in in abduction?
after the 1st 30 deg
what scapular motions accompany GH flexion?
upward rotation
pronation
elevation
what scapular motions accompany GH extension?
downward rotation
retraction
depression
what scapular motions accompany GH abduction?
upward rotation
elevation
maybe protraction???
what scapular motions accompany GH adduction?
downward rotation
depression
maybe retraction????
what scapular motions accompany GH lateral rotation?
retraction
what scapular motions accompany GH medial rotation?
protraction
what scapular motions accompany GH horizontal abduction?
retraction
what scapular motions accompany GH horizontal adduction?
protraction
what is the function of the rotator cuff?
to depress the humeral head into the glenoid fossa
provide GH motion
what is the only SITS muscles that inserts on the lesser tubercle of the humerus?
subscap
supraspinatus
O: supraspinous fossa
I: greater tubercle
A: stabilize GH jt, GH abduction
N: suprascapular
how is the supraspinatus palpated?
in prone with the arm off the table
small bursts of abduction
what is the supraspinatus outlet?
the subacromial space below the coracoacromial arch
infraspinatus
O: infraspinous fossa
I: greater tubercle
A: stabilize GH jt, GH lat rot, hor abd
N: suprascapular
teres minor
O: axillary border of the scap
I: greater tubercle
A: stabilize GH jt, GH lat rot, hor abd
N: axillary
what is a synergist to the infraspinatus?
the teres minor
subscapularis
O: subscap fossa
I: lesser tubercle
A: stabilize GH jt, med rot
N: subscapular
deltoid
O: ant: lat 1/3 clavicle
mid: acromion
post: scap spine
I: deltoid tuberosity
A: all: GH abd
ant: flex, med rot, hor abd
mid: abd only
post: ext, lat rot, hor abd
N: axillary
t/f: the ant and post deltoids are neutralizers of GH abd
true
pec major
O: clavicular: mid 1/3 clavicle
sternocostal: sternum, 1-6 ribs
I: lat lip of bicipital groove
A: clavicular: 1st 60 deg flex
sternocostal: 1st 60 deg ex
both: GH add, med rot, hor add
N: pectoral
how do you show the pec major 2 heads?
put one fist on top of the other and push them into each other
the one pushing down is showing the sternocostal portion?
the one pushing up is showing the clavicular portion?
coracobrachialis
O: coronoid process
I: mid humerus medially
A: GH flex
N: musculocutaneous
how is the coracobrachialis palpated?
with a flexed elbow to try and remove the biceps
latissimus dorsi
O: T7-12, posterior sacrum, illiac crest, and lower 3 ribs and some of inferior scap angle
I: med lip of bicipital groove of humerus
A: GH ext, add, med rot, and scap depression (reverse in CKC)
N: thoracodorsal
teres major
O: axillary border of scap near inf angle
I: lesser tubercle, below lats attachment
A: GH ext, add, med rot
N: subscapular
what are the prime movers of GH extension?
lats, teres major, post delt, pec major (sternocostal)
what are the prime movers of GH flexion?
coracobrachialis, ant delt, pec major (clav)
what are the prime movers of GH abduction?
mid delt, supraspinatus
what are the prime movers of GH adduction?
pec major, lats, teres major
what are the prime movers of GH lateral rotation?
teres minor, infraspinatus, post delt
what are the prime movers of GH medial rotation?
subscap, ant delt, lats, teres major, pec major
what are the prime movers of GH horizontal abduction?
post delt, infraspinatus, teres minor
what are the prime movers of GH horizontal adduction?
ant delt, pec major
what is a subluxation?
partial dissociation of articular surfaces common with low muscle tone
what is a dislocation?
complete dissociation of the articular surfaces that can also include labral tears and capsule damage
which is worse a subluxation or dislocation?
a dislocation
what results in subacromial impingement syndrome?
limited medial rotation and abduction due to impingement
what is one of the most commonly diagnosed shoulder injuries?
subacromial impingement syndrome
what is a rotator cuff tear?
a tear of one or all SITS muscles/tendons especially with overhead and throwing motions
what is bicipital tendinitis?
inflammation of the tendon passing through the bicipital groove (long head of biceps tendon)
what is adhesive capsulitis?
frozen shoulder
what are the 3 jts in the elbow?
humeroulnar
humeroradial
radioulnar
what are the motions of the humeroulnar jt?
flex/ex (sag, x)
what are the motions of the humeroradial jt?
flex/ex (sag, x)
what are the motions of the radioulnar jt?
pronation/supination (tran, y)
what are the functions of the elbow jts?
stability via bony configuration and soft tissue
mobility via muscular pull or multi-jt function
what side is the trochlea of the humerus on?
medial above the ulna
what side is the capitulum of the humerus on?
lateral above the radius
the axis of flex/ex at the elbow is through what 2 landmarks?
the trochlea and capitulum
what tendons attach to the medial epicondyle?
wrist flexors and pronators
flexor carpi radialis, flexor carpi ulnaris, flexor disitorum profundus, flexor digitorum superficialis
what tendons attach to the lateral epicondyle?
wrist extensors and supinators
why are the epicondyles a frequent site for pathologic changes?
bc of overuse
where is the elbow the most stable?
at full extension or the last 20% of flexion????
when do ligaments provide the elbow with the most support?
at greater than 20% flexion
what kind of jts are the humeroulnar and humeroradial jts?
hinge jts
how many DF do the HR and HU jts have?
1
what is normal flexion at the elbow?
145-160 deg
what is normal extension at the elbow?
0 deg
what landmark of the elbow is more distal, the capitulum or trochlea?
trochlea
the distal humerus is rotated ____ and the proximal ulna is rotated ____
anteriorly, posteriorly
what is the carrying angle?
the angle b/w the long axis of the humerus and long axis of the forearm
what is a normal carrying angle?
5-15 deg
what is cubitus valgus?
an increased carrying angle
30 deg
forearm is more laterally headed
what is cubitus varus?
decreased carrying angle
-5 deg
forearm is more medially headed
how many DF does the RU jt have?
1
what happens to the radius and ulna during pronation/supination?
the radius crosses over the stable ulna
describe the arthrokinematics of the humeroulnar jt
the concave ulnar trochlear notch moving on the convex humeral trochlea)
same roll and glide
extension to flexion=ant roll and glide
flexion to extension=post roll and glide
flexion of the humeroulnar joint is b/w what 2 bony landmarks?
coronoid-coronoid fossa
flexion at the HU jt requires…
sufficient length of posterior capsule, posterior fibers of MCL, ulnar nerve, and elbow extensors
extension at the HU jt requires…
sufficient length of anterior capsule, anterior fibers of MCL, elbow flexors
extension of the HU jt is b/w what 2 bony landmarks?
olecranon-olecranon fossa
describe the humeroradial arthrokinematics
concave proximal radius on moving on the convex capitulum
same roll and glide
at the HR jt, with flexion the radial head slides into the ____ ____
capitulotrochlear groove
t/f: at the HR jt, in full extension there is no contact b/w the radius and humerus
true
describe the arthokinematics of the proximal RU jt
the convex radial head moving on the concave radial notch on the ulna
radial head spinning on the radial notch
describe the arthrokinematics at the distal RU jt
concave ulnar notch of the radius moving on the convex ulnar head
in pronation, the radius rolls and glides anterior
in supination, the radius rolls and glides posterior
what soft tissues provide proximal jt stability at the RU jt?
annular ligament
LCL
oblique cord
quadrate ligament
what is the function of the annular ligament?
it circles around the radial head keeping it in contact w/the radial notch
what is the function of the oblique cord?
connects the lateral ulna and medial radius
becomes tight with supination to provide stability in supination
what is the function of the quadrate ligament?
a short and strong ligament that maintains jt b/w radial head and notch
what soft tissues provide distal RU jt stability?
articular disc (TFCC)
dorsal and palmar RU ligaments
interosseous membrane
what is a function of the interosseous membrane?
transmit forces efficiently into bigger bones
what is the CPP of the HU jt?
full elbow extension and supination
what is the OPP of the HU jt?
70 deg flex
10 deg sup
what is the CPP of the HR jt?
90 deg flex
5 deg sup
what is the OPP of the HR jt?
ext and sup
what is the OPP of the RU jt?
70 deg flex
35 deg sup
what is the CPP of the RU jt?
5 deg sup
brachialis
O: ant humerus distal 1/2
I: coronoid process, ulnar tuberosity
A: elbow flex (main elbow flexor)
N: musculocutaneous
biceps brachii
O: long head: supraglenoid tubercle of scap
short head: coracoid process of scap
I: radial tuberosity
A: elbow flex, sup, GH flex
N: musculocutaneous
brachioradialis
O: lat supracondylar ridge of humerus
I: radial styloid process
A: elbow flex, pro/sup from mid position
N: radial
triceps brachii
O: long head: infraglenoid tubercle of scap
lat (short) head: post lat humerus info to greater tubercle
med head: distal post humerus
I: olecranon process
A: elbow ext (main elbow extensor), GH ext
N: radial
anconeus
O: lat epicondyle of humerus
I: prox ulna inf to olecranon process
A: “unpinching”, weak elbow extensor
N: radial
pronator teres
O: humeral head: medial epicondyle
ulnar head: coronoid process of ulna
I: lat midpoint of radius
A: pronation (strongest pronator), weak elbow extension
N: median
pronator quadratus
O: ant distal 1/4 ulna
I: ant distal 1/4 radius
A: weak pronator
N: median
supinator
O: lat epicondyle of humerus and prox ulna
I: ant and lat prox radius
A: supination
N: radial
what are the prime movers of elbow flexion?
brachialis
biceps brachii (esp w/sup)
brachioradialis (esp w/forearm in midposition)
pronator teres (only w/forearm in pronation)
what are the prime movers of elbow extension?
triceps brachii
what are the prime movers of supination at the elbow?
supinator
biceps brachii (esp w/ elbow flex)
what are the prime movers of pronation at the elbow?
pronator teres
pronator quadratus
functional movement of the elbow and forearm is affected by ___ ___ and ____ ____
task demands, force requirements
t/f: injuries can change synergy requirements
true
are single joint or multijoint muscles recruited first?
single joint muscles
what is the recruitment order of the elbow flexors?
brachialis, biceps, brachioradialis
when is the biceps recruited first?
when elbow flexion and supination is needed
what is the order or recruitment of the elbow extensors?
anconeus, triceps
when is the triceps recruited?
with larger loads
what is the order of recruitment of supinators?
supinator, biceps
when is the biceps recruited for supination?
with the elbow flexed to 90 deg
t/f: the supinator is influenced by elbow angle
false
what is the order of recruitment of pronators?
pronator teres, pronator quadratus
is the pronator teres or quadratus consistently active?
the pronator quadratus
t/f: the pronator teres is influenced by elbow position
true
in the CKC, in extension does the elbow rely on bony geometry or muscles for stability?
bony geometry
in the CKC, in flexion, does the elbow rely on bony geometry or muscles for stability?
muscles
what factors affect maximum isometric force?
elongated position and/or IMA length
in what position do the supinators produce the greatest force?
in pronation
in what position do the pronators produce the greatest force?
in supination
the greater the IMA, the _____ the torque/force
greater
what are some common elbow pathologies?
medial epicondylitis
lateral epicondylitis
bicipital tendinitis
gunstock deformity
nursemaid’s elbow
what is medial epicondylitis?
overuse of worst flexors, pronators, and extrinsic finger flexors
also called golfer’s elbow or little league elbow
loss of full elbow extension
common in R elbow of R handed golfers from valgus forces
what is lateral epicondylitis
tennis elbow
overuse of backhand motions (extensors and supinators)
what is bicipital tendinitis?
inflammation and overuse of the biceps tendon (long head) passing through the bicipital groove
what is a gunstock deformity?
bow elbow
can result from a supracondylar fracture or malunion that causes a reduction in carrying angle
what is nursemaid’s elbow?
pulling the radius out of the annular ligament
can be a sign of child abuse
radial head subluxation
common among toddlers
causes pain, but is easy to fix w/no long term issues
