Biomechanics/Kines Midterm Flashcards
1
Q
kinematics
A
ROM
strength
speed
no regard to forces or torques
measured by goniometer and accelerator
2
Q
kinetics
A
forces
torques
muscle/joint interaction
effect of forces and torques on body
measured by transducer
3
Q
bones rotate around a plane that is…
A
… perpendicular to an axis of rotation
4
Q
degrees of freedom
A
number of independent directions of movement allowed at a joint
up to 3
5
Q
closed chain
A
proximal rotates against fixed distal
6
Q
open chain
A
distal rotates against fixed proximal
7
Q
convex-concave relationship improves
A
congruency
surface area for dissipating contact forces
helps glide motion between bones
8
Q
three movements between joints
A
roll - changes contact surface
slide - same cs
spin - rotations, same cs
9
Q
convex on concave
A
convex rolls and slides in opposite directions
10
Q
concave on convex
A
concave rolls and slides in similar directions
11
Q
where do articular surfaces fit best?
A
near end of ROM
called close packed position
provides stability to joint
12
Q
loose packed position
A
ligaments slackened
increase in accessory movements
least congruent near midrange
13
Q
when is the joint least congruent?
A
near the midrange
14
Q
when is net force zero
A
when acceleration of mass is zero
not moving
15
Q
what is the force that acts on body called?
A
a load
16
Q
time of loading
A
how long
17
Q
rate of loading
A
how fast
18
Q
viscoelastic
A
tissues in which physical properties associated with stress/strain curve change as function of time
creep phenomenon
19
Q
creep
A
progressive strain when exposed to constant load over time
reversible
20
Q
rate-sensitivity of viscoelastic
A
increased stiffness affords greater protection to underlying bone at time when forces acting on joint are greatest
21
Q
internal forces
A
within body
active or passive
22
Q
external forces
A
outside body
gravity or external load
23
Q
isometric
A
internal torque = external torque
24
Q
2 ways to produce torque
A
1) force perpendicular to AoR
2) moment arm distance > zero
25
concentric
internal > external
26
eccentric
external > internal
27
mechanics
study of motion of objects and the forces that cause motion
28
rigid-body mechanics
assume rigidity
saves considerable mathematical and modeling work without a great loss of accuracy
29
moment arm
perpendicular distance between axis of rotation and line of force
30
torque/moment
force multiplied by moment arm
tends to rotate body
could by internal or external
31
internal force
within body
produced by active muscle
32
joint reaction force
in reaction to net effect of internal and external forces
if IT and ET are equal, JRF = 0
33
mechanical advantage
ratio of internal moment arm to external moment arm
output force to input force
MA = a/b = Fb/Fa
34
primary movement of human body
through rotations of its limbs and trunks
non linear movement
35
what are movement and posture based on?
instantaneous interaction between internal and external torques
36
lever
rigid bar that turns about an axis of rotation or fulcrum
rotates about axis as result of force
force acts against resistance
37
lever function
create MA
magnify force (MA > 1)
increase speed and ROM through which the end of the lever moves (MA < 1)
balance equal forces (MA = 1)
38
mnemonic for levers
FRE 123
39
class 1 lever
fulcrum in middle
MA <, >, or = to 1
designed for speed and ROM when fulcrum closer to force
designed for strength when fulcrum closer to resistance
40
class 2 lever
resistance in middle
MA is > 1
advantage for force - farce arm is longer
41
class 3 lever
effort in middle
MA is < 1
advantage in speed and ROM
42
statics
no acceleration
described as equilibrium
43
dynamics
acceleration is occurring
system is not in equilibrium
44
where to hold the bat?
bottom for more torque
chocked up for speed
45
what percent of all musculoskeletal complaints is the shoulder responsible for?
~16%
46
orientation of clavicle:
deviated about 20 degrees posterior to frontal plane
47
orientation of scapula:
deviated about 35 degrees anterior to frontal plane
48
retroversion of humeral head:
about 30 degrees posterior to medial-lateral axis at elbow
49
how many joints make up the shoulder complex?
4
AC, GH, SC, scapulothoracic (ST)
50
arthrokinematics: roll
multiple points along one rotating articular surface contact multiple points on another
51
arthrokinematics: slide
single point on one surface contacts multiple points on another
52
arthrokinematics: spin
a single point on one surface contacts a single point on another
53
roll, spin, slide - convex/concave relationship
convex - knuckle and arm, opposite movement
concave - cupped hand and arm, same movement
54
which part of clavicle is convex/concave?
longitudinal is convex
transverse is concave
55
SC arthrokinematics
depression: glide superior, roll inferior
elevation: glide inferior, roll superior
protraction: glide and slide anterior
retraction: glide and slide posterior
56
SC arthrokinematics - depression
depression: glide superior, roll inferior
57
SC arthrokinematics - elevation
elevation: glide inferior, roll superior
58
SC arthrokinematics - protraction
protraction: glide and slide anterior
59
SC arthrokinematics - retraction
retraction: glide and slide posterior
60
ST joint elevation
scapula slides sup on thorax
anterior tilting at AC
61
ST depression
from elevated position, scap slides inf on thorax
62
ST protraction
medial border of scap sides ant-lat on thorax away from midline
internal rotation at AC joint
63
ST retraction
medial border of scap slides post-med on thorax toward midline
64
ST upward rotation
inf angle of scap rotates sup-lat, faceing glenoid fossa upward
65
ST downward rotation
from upward rotated position, inf angle of scap rotates in inf-med direction
66
what happens at SC and AC during ST elevation
ST elevation
SC elevation
AC downward rotation
67
what happens at SC and AC during ST protraction
ST protraction
SC protraction
slight horizontal place adjustments at AC
68
what happens at SC and AC during ST upward rotation
ST upward rotation
SC elevation
AC upward rotation
69
relationship of elevation at SC and upward rotation at AC
most of SC movement occurs 20-90 degrees
AC movement picks up from 140-180 degrees
impingement can occur after 90 degrees
70
functional importance of upward rotation at ST
glenoid need to sit upward
slight upward rotation needed for length tension relationship
subacromial spaces maintained to avoid impingement
accounts for approximately 1/3 of near 180 degrees
of shoulder abd and flex
71
how much humeral head does glenoid fossa cover
only about 1/3
longitudinal head is 1.9 times larger
transverse head is 2.3 times larger
72
what is a slap tear
labral tears at the top of the glenoid
73
superior glenohumeral ligament
anatomic neck, above lesser tubercle
adduction, inferior and AP translations of humeral head
74
middle GH lig
along anterior aspect of anatomic neck; also bends with subscap tendon
anterior translation of humeral head, especially in about 45-60 degrees of abduction; external rotation
75
inferior GH lig: axillary pouch
as a broad sheet to the anterior-inferior and posterior -inferior margins of the anatomic neck
90 degrees of abduction, combined with AP and inferior translation
76
inferior GH lig: anterior band
as a broad sheet to the anterior-inferior and posterior -inferior margins of the anatomic neck
90 degrees of abduction and full external rotation; anterior translation of humeral head
77
inferior GH lig: posterior band
as a broad sheet to the anterior-inferior and posterior -inferior margins of the anatomic neck
90 degrees of abduction and full internal rotation
78
coracohumeral lig
anterior side of greater tubercle; also blends with superior capsule and supraspinatus tendon
adduction; inferior translation of the humeral head; external rotation
79
GIRD
glenohumeral internal rotation deficit
common in overhead athletes
GH and ST deficiency
20 degree or greater loss of internal rotation
80
high velocity abduction and external rotation during cocking phase
motion twists and elongates middle GH ligh and anterior band of inferior GH lig
active motion tends to translate humeral head anteriorly
81
throwing phases
wind-up
early cocking
late cocking
acceleration
deceleration
follow-through
82
injuries during late cocking
anterior GH instability
RTC
SLAP tear
quadrilateral space syndrome
medial elbow instability
capitellar OCD
83
injuries during acceleration
internal impingement
rotator cuff tear (RTC)
scapulothoracic bursitis
medial elbow instability
olecranon apophysitis / stress fx
84
injuries during decleration
RTC
SLAP tear
subacromial impingement
posteromedial elbow impingement
85
injuries during follow through
olecranon apophysitis
olecranon stress fracture
86
why is the glenoid labrum so vulnerable to injury?
only loosely attached to glenoid rim
~50% of fibers of tendon of long head of biceps direct extensions of superior glenoid labrum
87
glenoid fossa tilt
5 degree upward tilt relative to medial border of scapula
88
GH abduction
inferior glide
superior roll
89
GH adduction
superior glide
inferior roll
90
external rotation
(vertical axis)
anterior glide
posterior roll
91
internal rotation
(vertical axis)
posterior glide
anterior roll
92
flexion
anterior spin
93
extension
posterior spin
94
scapulohumeral rhythm
for every 3 degrees of shoulder abduction, 2 degrees by GH abduction and 1 degree by ST upward rotation
95
6 kinematic principles associated with full abduction of shoulder
1. 2:1 SH rhythm shoulder abd 180 because 120 GH abd and 60 ST upward rotation
2. 60 UR of scap because SC elevation and AC UR
3. clavicle retracts at SC during shoulder abd
4. scap posteriorly tilts and externally rotates during shoulder abd
5. clavicle posteriorly rotates around own axis during shoulder abd
6. GH externally rotates during shoulder abd
96
scapular statistics
medial border ~3" from spine
between T2-T7
flat against thorax and rotated 30-35 degrees anterior to frontal plane
97
SICK scapula
scapular malposition
inferior medial border prominence
coracoid pain and malposition
dysKinesis of scapula (lack of proper movement)
98
3 types of dyskinesis
1. inferior medial scapular prominence
2. medial scapular border prominence
3. superomedial border prominence
1 and 2 associated with SLAP
3 associated with impingement and rotator cuff lesions
99
proximal stabilizers
originate on spine, ribs, and cranium
insert on scapula and clavicle
100
distal mobilizers
originate on scapula and clavicle
insert on humerus or forearm
101
ST elevators
upper trap
levator scapulae
rhomboids
support posture of shoulder girdle and upper extremity
102
ST depressors
lower traps
latissimus dorsi
pectoralis minor
subclavius
103
ST protractor
serratus anterior
forward pushing and reaching
final phase of pushup
104
ST retractors
middle trap - best
rhomboids
lower trap
middle trap has optimal line of force to retract scapula
active during pulling
scapular drifts into protraction of trap paralyzed
105
ST upper rotators
serratus anterior
upper and lower trap
106
ST downward rotators
rhomboids
pectoralis minor
107
muscle produces torque at a joint if
1. produces force in plane perpendicular to AoR (axis of rotation) of interest
AND
2. acts with associated moment arm distance > zero
108
three groups of elevators
1. elevate humerus at GH
2. scapular muscles that control upward rotation of ST
3. rotator cuff that control dynamic stability at GH
109
muscles responsible for elevation of arm by group
GH muscles
~ anterior and middle deltiod
~ supraspinatus
~ coracobrachialis
~ biceps long head
ST
~ serratus anterior
~ trap (upper and lower)
RC
~ supra
~ infra
~ teres minor
~ subscap
110
which RC have limited moment arm to abduct GH joint?
upper fibers of infraspinatus and subscapularis
111
supraspinatus role in shoulder abduction
rolls humeral head superiorly while also compressing joint
112
how cuff muscles control abduction at GH
supra: main compressor, drives superior roll
infra, TM, sub: exert depression on humeral head
infra and TM: externally rotate humerus
113
serratus anterior paralysis
downward rotated scapula - flaring
winging scapula
shortening of pec minor
114
subacromial impingement syndrome
most common painful disorder of shoulder
supra tendon, biceps long head tendon
"when I raise my arm, it hurts"
abd of 60 - 120 called the painful arc
115
possible causes of impingement syndrome
1. abnormal kinematics at GH and ST
2. slouched posture affecting ST alignment
3. fatigue, weakness, poor contorl, tightness of GH & ST muscles
4. inflammation and swelling in and around subacromial space
5. excessive wear and subsequent degeneration of tendons of rotator cuff
6. instability of GH
7. adhesions in inferior GH
8. excessive tightness in posterior GH
9. osteophytes forming aroung AC
10. abnormal shape of acromion or coracoaromial arch
116
where does slap tear affect.
posterior band of inferior GH lig
117
what does GIRD affect
posterior band of the inferior GH lig
118
Is motion of shoulder required for supination and pronation of the palm?
no
119
what joints make up the elbow and forearm complex?
humero-ulnar
humero-radial
proximal radio-ulnar
distal radio-ulnar
120
what provides stability at humero-ulnar joint?
tight fit between trochlea and trochlear notch
121
what type of joint is the elbow?
ginglymus or hinged
modifies hinge because there is slight axial rotation as it flexes/extends
122
what is the normal angle of the elbow
15 degrees valgus
ulna deviates laterally relative to humerus
carrying angle
valgus deformity - 30 lateral
varus deformity - 5 medial
123
who would have greater carrying angle between men and women?
women by 2 degrees
greater on dominant arm regardless of gender
124
valgus when elbow is extended
exceeds ~20-25 degrees
125
gunstock deformity
varus deformity where forearm deviated toward midline
can be born with it
126
what form of trauma can varus/valgus deformity result from?
severe fracture through growth plate of distal humerus in children
excessive valgus may damage ulnar nerve as it cross medial to elbow. it will slip in and out of the groove
127
articular capsule of elbow
encloses HU, HR, and PRU
thin and reinforced anteriorly by oblique bands of
fibrous tissue
synovial membrane lines internal surface of capsule
128
collateral ligaments stregnthen ...
articular capsule
they provide an important source of stability to elbow joint
129
medial collateral ligament
anterior fibers: strongest and stiffest, commonly torn by throwers, most significant resistance against valgus
posterior fibers
transverse fibers:
130
anterior fibers of MCL
origin: medial epicondyle
insertion: medial coronoid process
taught through sag plane movement (flex/ext)
provide articular stability throughout entire ROM
131
posterior fibers of MCL
origin: posterior medial epicondyle
insertion: medial olecranon process
resist valgus and extreme elbow flexion
132
transverse fibers of MCL
cross from olecranon to coronoid
do not resist anything
133
dynamic medial stabilizers
proximal fibers of wrist flexor and pronator groups
resist excessive valgus at elbow
most important: flexor carpi ulnaris
134
fall onto an outstretched arm and hand (FOOSH)
fully extended elbow forced into excessive valgus
may result in fracture of radius, ulnar nerve, anterior capsule or MCL injury
135
how much compression force does radius absorb?
80%
136
lateral collateral lig
origins on lateral epicondyle and immediately splits into two fiber bundles
taut during full flexion
stabilize during varus
137
radial collateral lig
fans from lateral epicondyle to blend with annular lig
138
lateral (ulnar) collateral lig
spans from lateral epicondyle and inserts to superior crest of ulna
139
guy wires of elbow
LUCL and AMCL
provide medial-lateral stability to ulnar during sag plane movement
140
what does rupture of LCL cause?
varus of elbow and posterior lateral rotary instability
expressed as excessive external rotation of forearm
141
motions that increase tension in CL of elbow
AMCL - valgus, ext/flex
PMCL - valgus, flex
LRCL- varus, external rotation
LUCL - varus, external rotation, flex
annular- distraction of radius, external rotation
142
elbow flexion contracture
muscles abnormally stiff after long periods of
immobilization in flexed and shortened position
increased stiffness may occur in anterior capsule and
some anterior fibers of MCL
tightness in flexors if cannot fully extend
143
in what activities does elbow extension occur?
throwing
pushing
reaching
144
maximal range of passive ROM generally available to elbow
5 degrees beyond neutral extension through 145 degrees of flexion
145
functional arc of elbow
30 - 130 degrees of flexion
loss of extremes usually results in only minimal functional impairment
146
humero-ulnar joint articulation
concave trochlear notch of ulna
convex trochlea of humerus
motion limited to sagittal plane
147
how much of articular surface does hyaline cover of trochlea and trohlear notch?
trochlea - 300 degrees
notch - 180 degrees
148
what stabilizes healthy HU joint in extension?
articular congruency and increased tension in stretched connective tissues
149
humero ulnar joint flexion
roll and slide superior
150
HUJ dislocation
trochlear notch of ulna may dislocate posterior to trochlea of humerus in severe elbow injuries
caused by FOOSH
151
HRJ articulation
between cuplike fovea of radial head and reciprocally shaped rounded capitulum
152
HRJ flexion
roll and slide superiorly
153
explain the motion of supination and pronation
occurs around an axis of rotation that extends from radial head through ulnar head - an axis that intersects and connects both radio-ulnar joints
154
when are radius and ulnar parallel?
in full supination
155
when does radius cross over ulna?
in full pronation
thumb will stay with radius in pronation
156
what is the midway between complete pronation and supination?
thumbs up position
157
what are the average ROM's through pro/sup
pronation: 75 degrees
supination: 85 degrees
several ADLs require only 100 degrees rotation, 50 pro through 50 sup
158
how many degrees of rotation can a person lack and still complete ADLs?
30 degrees
159
how to compensate for pro/sup?
pronation: internally rotating shoulder
supination: externally rotating shoulder
160
supination at PRUJ
rotation of radial head with fibro-osseous ring formed by annular ligament and radial notch of ulnar
161
which arm bone is fixed in open chain sup/pro?
ulna
162
DRUJ supination (open chain)
roll and slide inferior
163
PRUJ supination (open chain)
external rotation
164
DRUJ pronation (open chain)
roll and slide superior
165
PRUJ pronation (open chain)
internal rotation
166
screw home of elbow
proximal migration of radius and increased joint compression of HRJ
167
PRUJ pronation (closed chain)
external rotation
168
DRUJ pronation (closed chain)
slide posterior, roll anterior
169
PRUJ supination (closed chain)
internal rotation
170
DRUJ supination (closed chain)
slide anterior, roll posterior
171
force-couple
used to pronate forearm from weight bearing position
infraspinatus rotates humerus relative to fixed scapula, whereas pronator quadratus rotates ulna relative to fixed radius
172
arthrokinematics of pro/sup at PRUJ while weight bearing
annular lig and radial notch of ulna rotate around fixed radial head
173
arthrokinematics of pro/sup at PRUJ while non-weight bearing
radial head rotates within ring formed by annular lig and radial notch of ulna
174
arthrokinematics of pro/sup at DRUJ while weight bearing
convex ulnar head rolls and slides in opposite direction on concave ulnar notch of radius
175
arthrokinematics of pro/sup at DRUJ while non-weight bearing
concavity of ulnar notch of radius rolls and slides in similar directions on convex ulna head
176
function of elbow muscles
muscles that attach distally on ulna flex/extend but do not pro/sup
muscles that attach distally on radius my flex/extend but also can pro/sup
177
primary elbow flexors
biceps brachii
brachialis
brachioradialis
pronator teres
178
brachialis has larger ...
(biomech variables)
volume: 59.3 cm3
physiologic cross-sectional area: 7.0 cm2
179
brachioradialis has larger ...
(biomech variables)
internal moment arm: 5.19 cm
180
biceps brachii O/I
origin on scapula
insertion on radial tuberosity on radius
181
biceps brachii EMG signal
maximal when both flexion and supination simultaneous
low signal when flexion with pronation
182
brachialis O/I
origin: anterior humerus
insertion: proximal ulna
183
brachialis sole purpose
to flex elbow
expected to generate greatest force of any muscle crossing elbow
184
brachioradialis O/I
origin: lateral supracondylar ridge of humerus
insertion: styloid process of radius
185
what is the longest of all elbow muscles?
brachioradialis
186
what does maximal shortening of brachioradialis cause?
full elbow flexion and rotation of forearm to near neutral position
187
bowstring
brachioradialis muscle on anterior-lateral aspect of forearm
resisted elbow flexion, from a position of about 90 degrees of flexion and neutral forearm rotation
188
triceps brachii O/I
long head origin: infraglenoid tubercle
medial head origin: posterior side of humerus
lateral head origin: along radial groove
insertion: olecranon process
189
action of long head to triceps
extend and adduct shoulder
190
triceps long head biomech variables
volume: 66.6 cm3
191
anconeus location
between lateral epicondyle of humerus and along posterior aspect of proximal ulna
small cross-sectional area and small moment arm for extension
provides longitudinal and ML stability across HUJ
192
combining shoulder rotation with supination and pronation allow the hand to rotate how many degrees?
nearly 360 degrees
193
supinator muscles
supinator
biceps brachii
radial wrist extensors
extensor pollicis longus
extensor indicis
brachioradialis (from pronated position)
194
pronator muscles
pronator teres
pronator quadratus
flexor carpi radialis
palmaris longus
brachioradialis (from supinated position)
195
how many degrees of ulnar tilt and what motion does it restrict?
25 degrees of ulnar tilt
restricts radial deviation
scaphoid runs into radial styloid
196
how many degrees of palmar tilt and what motion does it restrict?
10 degrees of palmar tilt
resits extension
197
what is the shape of the distal articular surface of the radius?
concave
198
two commonly injured ligaments in distal radio-ulnar joint?
ulnar collateral
palmar capsular
199
what happens when fracture heals abnormally?
might lose ROM due to misalignment in joint
200
who develops ulnar drift?
those who have degenerative arthritis
201
the palmar side of carpal bones are what shape and what ligament arches over?
concave
transverse carpal ligament
202
four points that transverse carpal ligament connects to
pisiform and hamate on ulnar side
tubercles of scaphoid and trapezium on radial side
203
carpal tunnel is a passage way for what?
median nerve and tendons of extrinsic flexor muscles of digits
restrains tendons from bowstringing when wrist flexes
204
which carpals are vulnerable to compression injuries?
scaphiod and lunate
205
what is AVN
bone death from lack of blood flow
206
scaphoid is what percent of all carpal fractures?
60-70%
207
common MOI for carpal fractures?
fully supinated forearm
wrist fully extended and radially deviated
second common is punching
208
what artery supplies scahpoid?
radial artery
anterior interosseous artery
209
proximal 1/3 of scaphoid relies on what for blood flow?
retrograde blood flow because it has poor circulation
210
when scaphoid fracture is present where would be tender?
anatomical snuff box
211
location most of scaphoid fractures
along "waist" (between poles)
212
management of proximal pole fracture
typically require surgery
immobilization for 12+ weeks
213
management of distal pole fracture
no surgery if non-displaced
5-6 weeks of immobilization
214
flow of management of suspected scaphoid fracture
fracture visible
~displaced - ORIF
~undisplaced - CT
~~ displaced - ORIF
~~ undisplaced - cast or ORIF
no fracture seen
~ MRI
~~ normal - no fracture
~~ abnormal - cast or ORIF
~ splint and review x ray
~~ no fracture with pain - bone scan/MRI
~~ no fracture, no pain - no fracture
215
other injuries associated with scaphoid fracture
fracture/dislocation of lunate
fracture of trapezium
fracture of distal radius
216
Keinbock's (lunatomalacia)
unknown cause
AVN of lunate
history of frequent trauma
ex. jack hammer operators
lunate becomes fragmented and shortened
217
treatment of keinbock's
may need to be removed if it totally collapses and disrupts kinematics and kinetics of wrist
mild - immobilization
may need to alter length of ulna or radius to reduce contact
advanced - partial fusion, lunate excision, proximal row carpectomy
218
what three things does treatment of keinbock's depend on?
functional limitation
pain
progression of disease
219
proximal components of radiocarpal joint
concave surfaces of radius and adjacent articular disk (triangular fibrocartilage)
220
distal components of radiocarpal joint
convex proximal surfaces of scaphoid and lunate
triquetrum when in full ulnar deviation because it contacts articulate disc
221
percent of total compression force through articular disc and how much through scaphoid and lunate?
20% through articular disc
80% through scaphoid and lunate
222
when are contact areas greatest in RCJ
wrist partially extended and ulnar deviated
this is where maximal grip strength os obtained
223
what is the medial compartment formed by
convex head of capitate and apex of hamate fitting into concave recess of scaphoid, lunate and triquetrum
224
lateral compartment
concave trapezoid and trapezium fitting into convex scaphoid
has less movement
225
how many degrees of freedom at wrist
2
flex/ext
deviation
226
axis for flexion/extension at wrist
ML
227
axis for radial and ulnar deviation
AP
228
which carpal bone is axis of rotation for hand?
capitate
229
wrist flex/ext ROM
sagittal plane
total 130-160 degrees
flexes from 0 to 70-85
extends from 0 to 60-75
more flexion due to palmar tilt
230
wrist ulnar/radial deviation ROM
frontal plane
total 50-60 degrees
ulnar form 0 to 35-40
radial from 0 to 15-20
231
how to measure wrist devation
measured as angle between radius and shaft of 3rd metacarpal
232
average resting position for wrist
about 10-15 degrees extension and 10 degrees ulnar deviation
233
what kind of system is wrist
double joint system
234
arthro for wrist extension for both midcarpal and radiocarpal joints
roll posterior and slide anterior
roll follows fingers
convex on concave
235
arthro for wrist flexion for both midcarpal and radiocarpal joints
roll anterior and slide posterior
236
close packed position in wrist
full extension
237
arthro for ulnar deviation for both midcarpal and radiocarpal joints
roll ulnarly and slide radially
roll follows thumb
convex on concave
238
arthro for radial deviation for both midcarpal and radiocarpal joints
roll radially and slide ulnarly
239
which carpal joint has more radial deviation
greater at mid-carpal
radiocarpal radial deviation limited because carpus impinges against radial styloid
240
is carpal instability static or dynamic?
can be both or either one
241
rotational collapse of wrist
zigzag deformity
dorsal intercalated segment instability - lunate's distal end dorsal
volar intercalated segment instability - lunates distal end volar
242
what happens to produce zigzag deformity
compression from both ends
ex: punch or fall
243
what condition weakens ligaments of wrist
rheumatoid arthritis
244
double V system of ligaments
distal inverted V - medial and lateral legs of palmar intercarpal
proximal inverted V - palmar ulnocarpal and palmar radiocarpal
245
for ulnar deviation, which double V ligs are taut
lateral leg
palmar ulnocarpal lig
246
for radial deviation, which double V ligs are taut
medial leg
palmar radiocarpal lig
247
wrist extensors
extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris
extensor digitorum
extensor indicis
extensor digiti minimi
extensor pollicis longus
248
where is maximal grip
30 degrees of extension
249
wirst flexors
flexor carpi radialis
flexor carpi ulnaris
palmaris longus
flexor digitorum profundus
flexor digitorum superficialis
flexor pollicis longus
abductor pollicis longus
extensor pollicis brevis
250
radial wrist deviators
extensor carpi radialis longus
extensor carpi radialis brevis
extensor pollicis longus
extensor pollicis brevis
flexor carpi radialis
abductor pollicis longus
flexor pollicis longus
251
wrist ulnar deviators
extensor carpi ulnaris
flexor carpi ulnaris
flexor digitorum profundus and superficialis
extensor digitorum
252
shape of proximal base of 1st metacarpal
convex longitudinal
concave transverse
253
thumb movements and planes
abd/add in sagittal
flex/ext in frontal
254
arthro of thumb abduction
roll anteriorly and slide posteriorly
255
arthro of thumb adduction
roll posteriorly and slide anteriorly
256
arthro of thumb flexion
roll and slide anterior
257
arthro of thumb extension
roll and slide posterior
258
MCP movements and planes
flex/ext in sag
abd/add in frontal
259
arthro of MCP flexion
roll and slide anteriorly
260
arthro of MCP extension
roll and slide posteriory
261
arthro of MCP abd
roll and slide radially
262
arthro of MCP add
roll and slide ulnarly
263
arthro of IP flexion
roll and slide anteriorly
264
arthro of IP extension
roll and slide posteriorly
265
axial skeleton
head, spine, sacrum
266
appendicular skeleton
limbs including scapulas
267
how many functional components of the intervertebral junction?
3
transverse and spinous processes
apophyseal joints
an interbody joint
268
where does the cauda equina start?
L2
269
what plane is spine flex/ext?
sag
ML axis
270
what plane is spine lateral flexion?
frontal
AP axis
271
what plane is spine axial rotation?
horizontal
vertical axis
272
which facets favor which motion?
horizontal facets favor axial rotation
vertical facets favor block axial rotation
273
how are collagen fibers arranged?
multiple concentric layers
every other layer running in identical directions
orientation of each fiber about 65 degrees from vertical
274
ligamentum flavum
between anterior surface of one lamina and posterior surface of lamina below
limits flexion
80% elastin and 20% collagen
acts as barrier to material that could buckle cord in some regions of ROM
275
supraspinous and interspinous ligaments
between adjacent spinous processes from C7 to sacrum
limit flexion
interspinous guides sliding motion of facet joints
276
intertransverse ligaments
between adjacent transverse processes
limits contralateral lateral flexion and forward flexion
277
anterior longitudinal ligament
between basilar part of occipital bone and entire length of anterior surfaces of all vertebral bodies, including sacrum
limits extension or excessive lordosis in cervical and lumbar.
reinforces anterior sides of IVDs
278
posterior longitudinal ligament
throughout length of posterior surfaces of all vertebral bodies between axis and sacrum
limits flexion
reinforces posterior sides of IVD
279
capsules of the apophyseal joints
margin of each apophyseal joint
strengthen apop joints
surrounds the joint itself
280
when are only muscle contributions considered in mechanics to support spine?
lumbar spine neither flexed nor extended
(neutral lordosis)
281
who should not be prescribed flexion exercises?
shear pathology - spondylolisthesis
282
ROM at atlanto-occipital joint C0-C1
flex - 5
ext - 10
total - 15
axial rot - none
lateral flexion - 5
283
ROM at atlanto-axial joint complex C1-C2
flex - 5
ext - 10
total - 15
axial rot - 35-40
lateral flexion - none
284
ROM at intracervical region C2-C7
flex - 35-40
ext - 55-60
total - 90-100
axial rot - 30-35
lateral flexion - 30-35
285
total ROM across craniocervical region
flex - 45-50
ext - 75-80
total - 120-130
axial rot - 65-75
lateral flexion - 35-40
286
arthro of cervical extension
AO - roll posterior, slide anterior
AA - tilt posterior
ICR - slide posterior, ALL tense
287
arthro of cervical flexion
AO - roll anterior, slide posterior
AA - tilt anterior
ICR - slide anterior, lig nuchae, interspinous tense
288
arthro of protraction of cranium
lower to mid cervical flexes and upper craniocervical extends
289
arthro of retraction of cranium
lower to mid cervical extends and upper craniocervical flexes
290
arthro of craniocervical axial rotation
slides in opposite directions
spinous process to left - left transverse slides anterior and right slides posterior
291
arthro of craniocervical lateral flexion
AOJ - roll toward flexion and slide away
ICR - opposite slides.
292
spinal coupling between lateral flexion and axial rotation
45 degree inclination of articular facets of C2-C7
ex lateral flexion to right occurs with slight axial rotation to the right
293
compensatory action in spinal coupling
during lateral flexion to the right, cranium rotates to left to conceal that it actually rotated to the right
helps eyes fixate of stationary object
294
ROM for thoracic region
flex: 30-40
ext: 20-25
total: 50-65
axial rotation: 30-35
lateral flexion: 25-30
295
arthro of thoracolumbar flexion
superior slide in both thoracic and lumbar
296
arthro of thoracolumbar extension
inferior slide in both thoracic and lumbar
297
thoracolumber flexion arc
85
35T + 50L
298
thoracolumber extension arc
35-40
20-25T + 15L
299
arthro of thoracolumbar lateral flexion
slides in opposite directions.
inferior sliding on the side you are bending towards
300
thoracolumbar lateral flexion arc
45
25T + 20L
301
lumbar ROM
flex: 40-50
ext: 15-20
total: 55-70
axial rotation: 5-7
lateral flexion: 20
302
anatomic consideration of the sacroiliac joints
pelvic ring transfers body weight bidirectionally between trunk and femurs
strength of ring depends on tight fit of sacrum wedged between two halves of pelvis
303
nutation at pelvis
sacrum tilts anteriorly
iliac tilts posteriorly
hip flexors and lumbar extensors are tight
304
counternutation at pelvis
sacrum tilts posteriorly
iliac tilts anteriorly
hip extensors and abdominal muscles are tight
305
how thick is the end plate of a vertebra
about 0.6 mm thick
it is thinnest in the central region
306
describe trabecular design
three orientations - one vertical and two oblique
307
how does a schmorl's node form?
local area of bone collapses under end plate to create a pit or crater
neutral spinal compression
often misdiagnosed as a herniated or degenerated disc
308
3 major components of IVD
nucleus pulposus
annulus fibrosis
end plates
309
load bearing abilities of annulus fibrosis
able to resist loads when disc is twisted
only 1/2 of the fibers can support this while the other half become disabled
under spine compression the annulus fibers bulge outward and become tensed
310
progressive disc injury
when little hydrostatic pressure is present
outer annulus bulges outward and inner bulges inward during disc compression
311
define disc bulge
expansion of disc material beyond its normal border
312
protrusion
disc material is displaced. a TRUE herniation
313
extrusion
NP protruded through all layers of AF but remains attached to disc of origin
314
sequestration
a free disc fragment located in epidural space.
can migrate
315
what motion is damage to annulus of disc associated with
repetitive flexion of the spine through full ROM
316
rotatores
attach between transverse and spinous processes of thoracic vertebrae
stabilize, extend and rotate the spine
317
intertransversarii
attach between transverse processes of adjacent lumbar vertebrae
lateral flexion and stabilize spine
318
extensors of thoracolumbar spine
longissimus
iliocostalis
multifidus groups
319
transversus abdominis
deepest muscle layer
maintain internal pressure
320
rectus abdominis
between ribs and pubis at front of pelvis
6 pack muscle
321
external oblique
twist trunk to opposite side
322
internal oblique
twist trunk to same side
323
caution to training psoas
substantial spine compression imposed on spine when psoas activated
324
where do the left and right innominate bones connect to form the pelvis?
anteriorly at pubic symphysis
posteriorly at sacrum
325
what spinal level is ASIS at?
L4
326
3 functions of the pelvis
attachment for many muscles
transmits weight of upper body to ischial tubs when
sitting and lower extremities when walking.
supports organs involved in bowel, bladder and
reproductive
327
3 external features of the pelvis
large fan shaped wing
cup shaped acetabulum
obturator foramen
328
what is the longest and strongest bone in the body?
femur
329
where does the femoral head project at its proximal end?
medially and slightly anteriorly
330
which way does the neck displace the shaft of femur?
laterally
331
which side of femur displays convexity?
anterior
332
how is stress dissipated through femur?
compression along posterior shaft
tension along anterior shaft
333
what affect does bowing of the femur have?
allows it to bear a greater load.
334
angle of inclination
in frontal plane
140-150 at birth
125 in adulthood
335
normal, vara and valga angles of inclination
normal: 125
vara: 105
valga: 140
336
severe malalignment of femoral head and acetabulum may lead to...
dislocation or stress induced degeneration of hip
337
what is femoral torsion?
rotation between shaft and neck
normally 15 degrees anterior to ML axis
338
normal and excessive anteversion and retroversion of femoral torsion angles
normal: 15
excessive: 35
retroversion: 5
339
what can excessive anteversion that persists into adulthood increase the likelihood of?
hip dislocation
articular incongruence
increased joint contact force
increased wear on articular cartilage
may lead to secondary OA
340
what gait pattern is excessive anteversion associated with?
in-toeing
exaggerated hip internal rotation
compensatory to guide head back into acetabulum
341
what muscles shorten with excessive anteversion?
internal rotator muscles and various ligaments.
this reduces external rotation ROM
common in CP with angle of 25-45
342
how does acetabulum project from pelvis?
laterally with varying amounts of inferior and anterior tilt
343
what can a dysplastic acetabulum lead to?
chronic dislocation and increased stress
leading to degeneration or OA
344
center edge angle
35
smaller angle leads to less superior coverage. lead to superior dislocation and high compression
CEA of 15 reduces normal contact area by 35%
345
acetabular anteversion angle
20
larger angle leads to anterior dislocation
346
where is excessive acetabular anteversion exposed?
anteriorly
347
what happens when acetabular anteversion is severe?
anterior dislocation and lesions of anterior labrum especially at extremes of external rotation
348
when is acetabulum retroverted?
if it projects directly laterally or even posterior-laterally
349
in hip flexion with knee extended which tissues are taut?
hamstrings
350
in hip flexion with knee flexed which tissues are taut?
inferior and posterior capsule
gluteus max
351
in hip extension with knee extended which tissues are taut?
iliofemoral lig
some of pubofemoral and ischiofemoral ligs
psoas major
352
in hip extension with knee flexed which tissues are taut?
rectus femoris
353
in hip abduction which tissues are taut?
pubofemoral lig
adductor muscles
354
in hip adduction which tissues are taut?
superior fibers of ischiofemoral lig
iliotibial band
abductors - TFL, glute med
355
in hip internal rotation which tissues are taut?
ischiofemoral lig
external rotators - piriformis, glute max
356
in hip external rotation which tissues are taut?
iliofemoral lig
pubofemoral lig
internal rotators - TFL, glute min
357
what is the close packed position of the hip
full extension, with slight internal rotation and slight abduction
elongates most of capsule
358
most congruent position in hip
NOT the same as close packed
90 deg flexion, moderate abduction and external rotation
359
femoral on pelvic
vex on cave
femur around fixed pelvis
360
pelvic on femoral
cave on vex
pelvis over fixed femur
361
hip movements in their planes
flex/ext in sag
abd/add in frontal
rotation in hori
362
kyphosis is related to what motion of pelvis?
nutation
sacral ant
ilium post
363
lordosis is related to what motion of pelvis?
counternutation
sacral post
ilium ant
364
femoral on pelvis flexion
roll post, slide ant
spin
365
femoral on pelvis extension
roll ant, slide post
spin
366
femoral on pelvis abduction
roll med, slide lat
367
femoral on pelvis adduction
roll lat, slide med
368
femoral on pelvis internal rotation
roll internal, slide external
369
femoral on pelvis external rotation
roll external, slide internal
370
lumbopelvic rhythm
rotation of pelvis over femoral heads typically changes configuration of lumbar spine
371
ipsidirectional LPR
pelvis and lumabr spine rotate in same direction
bend over
372
contradirectional LPR
pelvis rotates in one direction while lumbar spine rotates in opposite direction
stand back up
373
pelvic on femoral flexion
roll and slide anterior
pelvis tilt anterior
iliopsoas and erector spinae involved
374
pelvic on femoral extension
roll and slide posterior
pelvis tilt posterior
taut iliofemoral lig
375
pelvic on femoral abduction
roll and slide inferior
ilium goes inf
376
pelvic on femoral adduction
roll and slide superior
ilium goes sup
377
pelvic on femoral internal rotation
opposite hip rolls and slides internal
378
pelvic on femoral external rotation
opposite hip rolls and slides external
379
hip flexors
iliopsoas
sartorius
TFL
rectus femoris
adductor longus
pectineus
adductor brevis
gracilis
glute min (ant fibers)
380
hip adductors
pectineus
adductor longus
gracilis
adductor brevis
adductor magnus
biceps femoris (long head)
glute max (lower fibers)
quadratus femoris
381
hip internal rotators
no primary
glute min (ant fibers)
glute med (ant fibers)
TFL
adductor longus
adductor brevis
pectineus
382
hip extensors
glut max
biceps femoris (long head)
semitendinosus
semimembranosus
adductor magnus (post head)
glute med (post fibers)
adductor magnus (ant head)
383
hip abductors
glute med
glute min
TFL
piriformis
sartorius
384
hip external rotators
glute max
piriformis
obturator internus
gemellus superior
gemellus inferior
quadratus femoris
glute med (post fibers)
glute min (post fibers)
obturator externus
sartorius
biceps femoris (long head)
385
FonP hip flexion laying down
normal activation of abdo muscles
posterior pelvis tilt
rectus femoris
rectus abdominis
psoas
iliacus
386
FonP hip flexion laying down
reduced activation of abdo muscles
anterior pelvis tilt
back extended
lordosis
rectus abdominis not pulling as hard
387
biomechanical consequences of coxa vara
positive
~ increased moment arm
~ alignment may improve joint stability
negative
~ increased bending moment arm increases bending moment - increases shear force
~decreased functional length of hip abductors
388
biomechanical consequences of coxa valga
postive
~decreased bending moment arm - decreased shear forces
~increased functional length of hip abductor muscles
negative
~decrease moment arm
~alignment may favor joint dislocation
389
trendelenburg
gluteus med weakness
if right weak, right elevates and left drops
390
compensated trendelenburg
trunk moves to weaker side
lean to weaker side
shortens lever arm
391
anterior pelvic tilt
ASIS inf and PSIS sup
hip flexion
392
posterior pelvic tilt
ASIS sup and PSIS inf
hip extension
393
active and passive insufficiency
AI: two joint muscle cannot complete full ROM. if hip is flexed, knee can attain full flexion. if hip is extended, knee cannot fully flex
PI: two joint muscle cannot stretch maximally across both joints. if knee is fully extended, hip flexion is limited
394
what fraction of muscles that cross knee also cross hip or ankle?
2/3
395
why does axis of rotation change in knee?
due to curve of lateral epicondyle
396
describe articular cartilage of posterior patella
smooth
397
normal genu valgum angle
170-175
398
excessive genu valgum
< 170
knock-knee
more women
need to shift weight lat
399
genu varum
> 180
bow-leg
more men
need to shift weight med
400
vertical axis of rotation at hip
line connecting femoral head to center of knee joint to ankle and foot
mechanically links horizontal plane movements of major joints of entire limb
401
tibio femoral joint
convex femoral condyles and flat smaller tibial condyles
402
where does joint stability in knee come from?
muscles, ligaments, capsule, menisci, and body weight
403
describe the menisci
crescent-shaped, fibrocartilaginous structures
transfrom surfaces of tibia into shallow seats for larger convex femoral condyles
404
what are the free ends of the menisci called?
anterior and posterior horns
405
describe coronary ligament in menisci
attaches external edge of each meniscus to tibia and capsule
relatively loose to allow pivoting during movement
406
which menisci is more mobile
lateral
407
what does the transverse ligament in menisci do?
connects both menisci anteriorly
408
where is blood supply to menisci greatest?
peripheral (external) border
from capillaries within synovial membrane and capsule
409
blood supply at internal border of menisci
essentially avascular
410
describe the medial meniscus
oval shape
external border attaches to deep surface of MCL and adjacent capsule
411
describe the lateral meniscus
circular shape
external border attaches only to lateral capsule
tendon of popliteus passes between LCL and external border of lateral meniscus
412
actions of popliteus
med rot of tibia
flexion of knee
lat rot of femur
unlocking muscle of the knee
413
primary function of menisci
reduce compressive stress across tib/fem joint
414
4 secondary functions of menisci
stability in motion
lubrication of articular cartilage
providing proprioception
guide knee's arthrokinematics
415
how much area does menisci increase of joint contact?
triples it and decreases pressure
lateral meniscectomy increases peak contact pressure at knee by 230%
416
50% of ACL injuries associated with:
concurrent meniscus tears
417
meniscal tears associated with:
forceful axial rotation of femoral condyles over partially flexed and weight-bearing knee
axial torsion within compressed knee can pinch and dislodge meniscus
418
bucket-handle tear
dislodged or folded flap of meniscus can mechanically block knee movement
makes a clicking sound
419
which meniscus is injured more often
medial injured twice as much
axial rotation and external valgus force
420
what does valgu force do at the knee?
subsequent large stress on MCL and posterior-medial capsule
can indirectly injure medial meniscus
421
how many degrees of freedom at knee
2
flex/ex in sag
int/ext rot when knee is flexed
422
passive frontal plane movement is:
passive
6-7 degrees
423
sagittal movement at knee
open chain: cave on vex - same
closed chain: vex on cave - opposite
424
describe ML axis of rotation in knee
not fixed but migrates within femoral condyles
curved path - evolute
path of axis influenced by eccentric curvature
425
what does the migrating axis do the the moment arm in knee
alters length of moment arm of flexor and extensor muscles
external devices have fixed axis and therefore can rotate in dissimilar arc than knee
426
tibia on femoral extension
roll and slide anterior
427
tibia on femoral flexion
roll and slide posterior
428
femoral on tibia extension
roll anterior and slide posterior
429
femoral on tibia flexion
roll posterior and slide anterior
430
tib on fem internal rotation
tibia internal, femur stationary
431
tib on fem external rotation
tibia external, femur stationary
432
fem on tib internal rotation
tibia stationary, femur internal
433
fem on tib external roation
tibia stationary, femur external
434
axial rotation in the knee increases with what motion
knee flexed to 90 degrees
435
external to internal rotation ratio in knee
2:1
436
rotation when knee is fully extended
maximally restricted by ligaments, capsule, bony congruity
437
what muscle pulls menisci anteriorly
quadriceps
438
screw home rotation of knee
locking knee in extension requires about 10 degrees of external rotation
described as conjunct rotation - mechanically linked to flexion/extension kinematics
439
what position increases joint congruency and favors stability
final position of extension
440
what happens to femur when knee is in full extension?
femur slightly medially rotates on the tibia to lock knee joint in place
popliteus is key to unlock it bey flexion and lateral rotation
441
describe how popliteus rotates tibia and femur
rotate femur externally to initiate FonT flexion
rotate tibia internally to initiate TonF flexion
442
which muscles stabilize menisci?
popliteus
semimembranosus
443
MCL and posterior-medial capsule function
resists valgus/abd
resists knee extension
resists extremes of axial rotation (esp. ex rot)
444
MCL and posterior-medial capsule MOI
valgus producing force with foot planted
severe hypertension of knee
445
LCL function
resist varus/add
resist knee extension
resist extremes of axial rotation
446
LCL MOI
varus producing force with foot planted
sever hypertension of knee
447
ACL function
resist extension
~ anterior translation of tibia
~ posterior translation of femur
resists extremes of varus, valgus, axial rotation
448
ACL MOI
large varus force with foot planted
large axial rotation to knee with foot planted
any combo of above
sever hypertension of knee
449
PCL function
resist flexion
~anterior translation of femur
~ posterior translation of tibia
resists extremes of varus, valgus, axial rotation
450
PCL MOI
falling on flexed knee when proximal tibia strikes ground
forceful posterior translation of tibia or ant femur
large axial rotaion or varus/valgus
sever hypertension of knee causing gapping of posterior side of joint
451
how many ACL injuries are non contact or minimal contact?
70%
452
sartorius
hip flexion, external rotation, abd
knee flexion, int rot
453
gracilis
hip flex, add
knee flex, int rot
454
rectus femoris
knee ext
hip flex
455
vastus group
kne ext
456
popliteus
knee flex, int rot
457
semimembranosus
hip ext
knee flex, int rot
458
semitendinosus
hip ext
kne flex, int rot
459
biceps femoris short head
knee flex, ex rot
460
biceps femoris long head
hip ext
knee flex, ext rot
461
gastrocnemius
knee flex
ankle plantar flexion
462
plantaris
knee flexion
ankle plantar flexion
463
what does deeper squat require
greater force from quadriceps owing to greater external torque on knee
464
what happens with a larger Q-angle
larger lateral muscle pull on patella
465
lateral and medial forces in knee should:
counteract so that patella tracks optimally during flexion and extension of knee
466
excessive knee external rotation and valgus:
increases q-angle and increases lateral bowstringing force on patella
combo of internal femur rotation and external tibia rotation
