Bio mech 4 Final Exam1 Flashcards
(352 cards)
1
Q
What are the important joints of the shoulder complex (involved in arm movement)?
A
glenohumeral GH, Suprahumeral, scapulocostal, acromioclavicular AC, sternoclavicular SC.
2
Q
Of all the important joints of the shoulder complex are not true anatomical joints?
A
Suprahumeral, scapulocostal.
3
Q
name 5 other joints involved with the shoulder complex?
A
- Costosternal and costochondral joints. 2. Costotransverse and costovertebral joints. 3. cervical intervertebral. 4. Thoracic intervertebral. 5. Lumbar intervertebral.
4
Q
What is the arm trunk mechanism called?
A
Scapulohumeral rhythm.
5
Q
What is the arm trunk mechanism?
A
Complex movement involving many joints (described with flexion, abduction, extension, etc.)
6
Q
What movements are important in the scapulohumeral rhythm?
A
- scapulocostal. 2. Sternoclavicular. 3. AC. 4. GH.
7
Q
What is the “Shoulder Joint”?
A
GH.
8
Q
What type of joint is the GH?
A
ball and socket (enarthrosis) like the hip joint, but not really it is much more gliding and less like a ball and socket.
9
Q
Is the glenoid fossa shallow or deep?
A
shallow, smaller than the head of the humerus, only part of a socket, anteverted.
10
Q
What is the significance of a shallow glenoid fossa?
A
decreased stability.
11
Q
What is the significance of an anteverted glenoid fossa?
A
decreased anterior stability.
12
Q
What would happen with a retroverted glenoid fossa?
A
decreased posterior stability.
13
Q
What will increase the depth and size of the glenoid fossa?
A
the labrum.
14
Q
What is the lip of the glenoid labrum made of and what shape does it create?
A
fibrocartilagenous lip and is a complete O.
15
Q
Where will the glenoid labrum attach to?
A
the rim of the glenoid fossa, it is partially attached to the capsule, biceps long head partly or completely attaches to the superior labrum, rotater cuff attaches losely.
16
Q
What happens with superior labrum lesions?
A
S.L.A.P. which is superior labrum anterior posterior lesion (typically seen due to the long head of the biceps tendon attachment causing wear and tear on the labrum and or causing avulsion
17
Q
What is the healing of the labrum like and why will it need to heal?
A
It is poor healer due to fibrocartilage, but it is under constant loading and movement.
18
Q
Why is the labrum important?
A
Important for GH stability and normal function
19
Q
What are 3 common causes of labral damage?
A
dislocation, increased mobility (instability), overuse.
20
Q
What are some humeral head features?
A
1/3 of a sphere, retroverted, much larger than the glenoid fossa.
21
Q
What is the significance of a retroverted humeral head?
A
decreased congruency, decreased resistance to anterior translation, and increased posterior resistance.
22
Q
What part of the humerus will act like the trochanters of the femur?
A
Greater and lesser tubercles.
23
Q
What is in the intertubercular sulcus of the humerus?
A
The long head of the biceps tendon.
24
Q
How is the tendon of the long head of the biceps brachii held in the intertubercular sulcus and what will this location be like?
A
It is held in place by the transverse ligament and tendons of subscap and pect. Tendon is vulnerable in the sulcus.
25
Where will the GH joint be strong and weak at?
Strong- anterior and inferiorly. Weak- posteriorly.
26
What will the axillary folds be like in the GH joint?
like an accordion.
27
What are the 4 ligaments of the GH joint?
1. Coracohumeral. 2. Superior GH (SGHL). 3. Middle GH (MGHL). 4. Inferior GH (posterior and anteroir parts).
28
What is the most important ligament of the GH joint?
The inferior GH ligament.
29
What is F. Weitbrecht?
a large hole in the GH capsule between superior and middle GH ligaments (rotator cuff interval).
30
All the GH joint ligaments resist what motion?
External rotation.
31
What ligament will resist distraction and inferior translation of the GH joint and when?
Coracohumeral ligament with arm in a dependent position.
32
What is a dependent position?
arm is loosest pack positon which is when arm is dangling by the body resting.
33
What ligament will resist distraction , external rotation, and adduction of the GH joint and when?
Superior GH ligament with arm in a dempendent position.
34
What motion will the middle GH ligament resist and in what position?
Distraction, external rotation with arm abducted 45-60 degrees.
35
The inferior GH ligament is the most important ligament and is used when the arm is in what position?
>90 degrees abduction.
36
What is the Inferior GH ligament like with adduction?
It folds like an accordion.
37
What is the resting and tight packed position of the GH joint?
Resting- dependent position. Tight packed- abducted and externally rotated.
38
What will instability of the GH joint lead to?
Dislocation.
39
What will the static stability of the GH joint be?
capsule (Inferior GH ligament is most important) and labrum
40
What will the dynamic stability of the GH joint be?
Rotator cuff, biceps and triceps (pectoralis major) muscles.
41
When will the rotator cuff especially be a dynamic stabilizer of the GH joint?
With arm abducted.
42
What will happen to the stability of the GH joint with increased age?
Both static and dynamic stability goes down.
43
When is the GH joint most vulnerable to dislocation?
abduction and external rotation or landing on outstretched hand.
44
Most GH joint dislocations are _____.
anterior.
45
Where is the suprahumeral joint located at and it is aka what?
between coracoacromial arch and humeral head. Aka subacromial joint.
46
What are the 3 parts of the coracoacromial arch?
Coracoid process, acromion, Fibrous part is the coracoacromial ligament.
47
What are the contents of the suprahumeral joint?
subacromial bursa, rotator cuff tendon- especially supraspinatus, biceps brachii long head.
48
What is an important and negative occurrence at the suprahumeral joint?
It is a common site of impingement- a superior shoulder impingment.
49
What will decrease impingement of the suprahumeral joint?
external rotation, inferior translation, cuff and biceps.
50
What will increase impingement of the suprahumeral joint?
internal rotation, superior translation or any superior movement, deltoid, internal rotators and tricpes(long head), pec. Minor.
51
What does kyphosis, shoulder hiking and protraction have in common?
They all increase impingement
52
What will the acromioclavicular joint be like from birth to adulthood?
Birth- fibrocartilaginous symphysis. 3-4 years 2 cavities with fibrocartilage disc. Becomes a meniscus between 10-20 years. Appears degenerated by age 20-30 with lots of crepitus.
53
Is the acromioclavicular joint a vulnerable or a strong joint?
Small vulnerable joint.
54
What injury is common in the acromioclavicular joint?
AC separation (essentially a dislocation but separation is the terminology)
55
Can the GH joint be separated?
No, the GH undergoes dislocation only the AC will undergo AC separation
56
Does the AC joint have a strong or weak capsule?
Weak capsule with small superior and inferior reinforcements/ligaments.
57
What are the extracapsular ligaments of the acromioclavicular joint like?
Most important stabilizers that resist all distractive forces.
58
What are the extracapsular ligaments of the acromioclavicular joint?
Coracoclavicular ligaments; conoid and trapezoid.
59
What is the difference between a mild and a severe sprain of the acromioclavicular joint?
No step defect in mild sprains.
60
What will cause distraction of the AC joint?
abduction and horizontal abduction, flexion, external rotation, lifting, pull-up or chin-up.
61
What will cause compression of the AC joint?
adduction, horizontal adduction, pushing, push-up, and resisted horizontal abduction.
62
How will the SC joint dislocate ? And why are these rare?
Dislocations will be anteriorly if they occur typically rare because it would be lethal to dislocate posteriorly since the great vessels and airways are posterior to it
63
What is the shape of the SC joint?
Shallow ball and socket.
64
Which joint is larger and more stable the SC or AC?
SC.
65
What is the articular surface of the SC joint made of?
fibrocartilagenous articular surface.
66
Name the fibrocartilagenous articular surfaces in the body?
SC, TMJ, AC, and 1/2 of SI.
67
How common is the SC joint dislocated and why?
Rare due to greater depth of joint.
68
Which joint socket is deeper the GH or SC?
SC.
69
Will the SC joint have supportive muscles?
Yes strong support from pec. Major, trap, SCM, Subclavius.
70
What muscle will regulate control of movement of the clavical?
The subclavius and its fasciae.
71
What is unique about the interclavicular ligament?
It is one of the few ligaments that crosses midline of the body and supports the superior capsule of both SC joints
72
The SC joint has a capsule with what type of ligaments?
Anterior and posterior SC ligaments.
73
What ligament is very important at resisting distraction of the SC joint?
Anterior division of the costoclavicular ligament.
74
What will the posterior division of the costoclavicular ligament do?
keeps the clavical from pinchin against the disc in the articular capsule. Also limits depression, elevation, and internal rotation at SC joint.
75
Besides resisting distraction what will the anterior division of the costoclavicular ligament resist?
Depression, elevation, and external rotation of clavical at SC joint.
76
Conjoint movement can occur at the SC joint and what is it?
Clavicla moves in same direction and same way as humerus.
77
What does the clavicle connect?
The upper limb with the axial skeleton.
78
What joint will movement happen for clavicular movement to occur?
SC.
79
What is the significance of the clavicle moving conjointly with the humerus?
This creates less torsion.
80
What are the phases of scapulohumeral rhythm?
1. arm raised 0-30 degrees. 2. arm raised 30-90 degrees. 3. arm raised 90-180 degrees.
81
What accounts for 120 degrees of total scapulohumeral rhythm?
humerus at GH.
82
What accounts for the other 60 degrees of total scapulohumeral rhythm?
Scapula.
83
What will allow the clavicle to move during scapulohumeral rhythm and how?
SC joint results in 60 degrees of distal elevation.
84
What will allow the acromion to move during scapulohumeral rhythm and how?
AC joint resulting in 20 degrees total rotation with distal clavicle.
85
What is the big picture of scapulohumeral rhythm?
2/3 at GH and 1/3 involves shoulder girdle.
86
What position will the arm be in at the start of phase 1 of scapulohumeral rhythm?
dependent.
87
What is the GH:scap ratio during phase 1 of scapulohumeral rhythm?
it is 7:1.
88
What motion is happening at the GH joint during scapulohumeral rhythm during phase 1?
20-25 degrees GH abduction. Inferior slide and superior roll.
89
What muscle will abduct and elevate the humerus during phase 1?
deltoid.
90
What muscle will abduct and depress humerus during phase 1?
supraspinatus.
91
The rotator cuff does what during phase 1?
acts as a group to stabilize, depress and externally rotate throught all phases.
92
During phase 1 what muscles will initiate abduction?
Girdle- serratus anteiror(more important), trapezius. GH- supraspinatus(30-40%), deltiod(60-70%).
93
What happens to the scapula during phase 1?
variable at first and about 5 degrees of external rotation.
94
What muscles will create the 5 degrees of external rotation of the scapula during phase 1?
Serratus anterior, trapezius.
95
What happens if the trapezius are too involved in phase 1?
Premature, excessive or uneven hiking leading to increased impingment.
96
What will cause the trapezius muscle to get involved too early in phase 1?
weakness of the levator scapula.
97
What happens to the SC joint during phase 1?
about 5 degrees elevation of the clavicle, superior roll and inferior slide of SC joint done by the upper trapezius.
98
What happens at the AC joint during phase 1?
5 degrees rotation between clavicle and acromion.
99
What happens at the GH joint during phase 2?
about 40 more degrees of elevation done with inferior slide and superior roll, and has the same prime movers as phase 1.
100
What muscle will help abduct and depress the arm during phase 2?
Biceps helps if externally rotated
101
What will the rotator Cuff be doing during phase 2?
Depresses/ counteracts the deltoid muscle.
102
What muscles will externally rotate the arm during phase 2?
Teres minor and infraspinatus.
103
During which degrees of motion does maximum impingement occur?
70-120 degrees so during phase 2 and 3.
104
What happens to the scapula during phase 2?
additional 20-25 degrees done by the same muscles as phase 1, but upper trapezius is more involved than phase 1.
105
What is the major stabilizing muscle of phase 2 scapular movement?
Serratus anterior. If trapezius is too involved or uneven this can be bad.
106
What keeps the superior angle of the scapula from tiliting posterior? Why?
levator scapulae and this will avoid shoulder hiking?
107
What will the pectoralis minor muscle do during phase 2 if tight?
Antagonist and prevent external rotation of scapula.
108
What happens to the clavicle during phase 2?
SC- 20-25 degrees additional elevation done with inferior slide and superior roll done by the trapezius. AC- 0-5 degrees additional rotation.
109
Lack of SC motion during phase 2 leads to what?
increased motion and wear and tear on the AC joint.
110
How much of the movement have the clavicle and scapula moved at the end of phase 2?
half way.
111
What happens at the GH joint during phase 3?
additional 60 degrees of abduction, done by same kinematics and same primary movers.
112
When will shoulder impingment be a problem during phase 3?
up to 120 degrees and then again at 180 degrees.
113
What will the triceps long head do during phase 3?
reinforces the inferior GH capsule and this prevents the humerus from being instable inferiorly.
114
Most people have tight triceps and this might lead to what?
superior translation leading to impingment.
115
What prevnets anterior displacement of the GH joint during Phase 3?
inferior GH ligament, pectoralis major, subscapularis. If these muscles are tight it will decrease inferior translation and impingment.
116
GH ROM will be limited by what during phase 3?
Triceps, pectoralis major, subscapularis, latissimus dorsi, capsule especially inferior axillary fold.
117
What are the back muscles doing during phase 3?
externally and laterally flex spine while arm is raising.
118
What is happening to the scapula during phase 3?
additional 30 degrees external rotation done by same kinematics and muscles as other phases, but upper traps are more active.
119
What will limit scapular ROM during phase 3 and what is the significance?
Rhomoids, pectoralis minor, and middle traps. When tight it will increase movement somewhere else.
120
In general what will clavicular movement be like during phase 3?
Big changes.
121
What happens to the SC joint during phase 3?
additional 30 degrees elevation for a total of 60 degrees.
122
What causes rotation of the SC joint during phase 3?
conoid and trapezoid ligaments which pull the ligaments down to coracoid
123
SC ROM is limited by what during phase 3?
costoclavicular ligaments, subclavius, and pectoralis major.
124
What happens at the AC joint during phase 3?
10 degres of additional rotation for a total of 20 degrees.
125
What limits rotation of the AC joint during phase 3?
SC and AC ligaments, subclavius, pectoralis major.
126
What is the shape of the clavicle?
Crank shaped.
127
What happens to the clavicle during phase 1-2?
Mainly roll and slide.
128
What happens to the clavicle during phase 3?
Mainly external rotation due to taut ligaments.
129
What ligaments will be taut with calvicle movement during phase 3?
conoid and trapezoid ligaments.
130
What are the adductors at the GH that limit abduction?
Lats, teres major, pec major, triceps
131
What are the adductors at the girdle that limit abduction?
Rhomboids, traps and pec minor
132
What are the internal rotators at the GH that limit abduction?
Lat dorsi, pec major, teres major, subscapularis
133
What are the internal rotators at the girdle that limit abduction?
Lat dorsi, pec minor and rhomboids
134
What muscles limit flexion of the arm during phase 3?
Same as those that limit abduction.
135
What happens with tight muscles during phase 3?
causes impingment and limits movement.
136
What are the 3 joints of the elbow and what type of joints are they?
1. Humeroulnar joint- hinge. 2. Humeroradial- pivot. 3. proximal radioulnar- gliding or pivot but really just gliding.
137
What part of the elbow will muscles attach to?
Epicondyles never Condyles.
138
Radius articulates with the ____ of the humerus and the ulna articulates with the _____ of the humerus.
capitellum and trochlea/ coronoid fossa.
139
What is the ulnar tuberosity an attachment site for?
Pronator teres and brachialis
140
What is the radial tuberosity an attachment site for?
Biceps
141
What part of the ulna articulates with the coronoid fossa?
coronoid process.
142
What are the condyles of the humerus?
Capitellum and trochlea.
143
What does trochlea mean
Spool.
144
Which condyle of the humerus is longer?
Medial condyle aka trochlea
145
Capitellum means what?
Little head.
146
Will the arm and forearm be in a straigth line?
No.
147
What will be larger the medial or lateral epicondyle of the humerus?
Medial is larger.
148
How many muscles attach to the medial and lateral epicondyles of the humerus?
Medial- 5 muscles. Lateral- 5 muscles.
149
What muscles and ligaments that attach to the medial epicondyle of the humerus?
Common Flexor Tendon (Pronator teres, Palmaris Longus, Flexor Carpi Ulnaris, Flexor carpi radialis, Flexor digitorum superficialis) and MCL or UCL
150
What muscles and ligaments that attach to the lateral epicondyle of the humerus?
Common extensor tendon (5 muscles = Extensor Carpi Radialis Brevis, Extensor digitorium, Extensor carpi Ulnaris, Supinator and anconeus) and the LCL or RCL
151
What is the carrying angle?
the elbow will be in valgus and this is only possible when the arm is extended and supinated like in anatomical position.
152
Who has a larger carrying angle males or females?
Females > males.
153
What causes varus of the elbow?
flexed, pronated and fracture leading to growth arrest.
154
Cubital varum is aka?
Gun stock elbow. (elbows bent outwards)
155
What is cubitus valgum?
Excessive valgus or forearm is more abducted
156
What does cubitus mean?
Elbow.
157
Gunstock elbows occur after what?
Fractures.
158
How are the condyles of the elbow angled?
Forward 45 degrees.
159
What will trochlear fossa position be like? Why?
Anterverted to increase flexion ROM.
160
Fractures of the elbow cause malunion which leads to what?
change is flexion and extension ROM and may affect carrying angle.
161
What happens to the humerus during development?
external torsion occurs.
162
Distal end of humerus is about ____ degrees external (due to torsion) to proximal end?
15 degrees and this is opposite of the femur.
163
Why will the humerus develop with 15 degrees external torsion?
TO increase supination ROM.
164
When measuring flexion and extension of the elbow what is the neutral position?
0 degrees extended.
165
What is the amount of flexion and extension of the elbow and is it greater in males or females?
flexion- 150 degrees. Extension- 0-15 degrees and larger ROM in females.
166
Will males or females have a greater amount of flexion and extension of the elbow?
Women because women usually have more laxity of ligaments and less soft tissue than men
167
When measuring supination and pronation of the forearm what is the neutral position?
Not anatomical, but elbow is at 90 degrees and thumb pointing up and arms in front of body.
168
What are the amounts of supination and pronation?
Meausered at the hand- 90 degrees. Meausered at the forearm- 80 degrees.
169
Who will have more supination and pronation ROM males or females?
Males.
170
What is the tight packed position of the elbow?
Anatomical position.
171
What is the resting position of the elbow?
70 degrees flexed and 10 degrees supinated.
172
Why is the resting position of the elbow important?
This is how a sling should be put since it is the loosest position to allow for healing
173
When will the anterior capule of the elbow be tight?
Only when fully extended.
174
What is the most important ligament of the elbow?
Ulnar collateral.
175
What ligament is most important when the elbow is flexed?
MCL.
176
What is most important stabilizer when the elbow is straight?
Interlocking bones.
177
Which ligament of the elbow is not very significant?
LCL.
178
What stresses will the MCL of the elbow resist?
Hyperextension, distraction, valgus stress when the elbow is flexed.
179
Where does the MCL originate and insert?
Medial epicondyle of humerus to medial proximal ulna
180
What stresses will the anterior oblique capsular ligament of the elbow resist?
hyperextension, and varus and valgus when the elbow is extended.
181
Where does the anterior oblique ligament originate and attach to?
medial epicondyle to the annular ligament and radius (allows for oblique reinforcement)
182
What stresses will the annular ligaments of the elbow resist?
Resists radial head distraction
183
Where does the annular ligament originate and attach to?
anterior and posterior edges of the radial notch, the lateral collateral and oblique capsular ligment attach to the annular ligament
184
What does the LCL resist?
Resists varus stress
185
What does the MCL resist?
Valgus stress (and resists throwing)
186
Which collateral is small/weak?
LCL which attaches to the annular ligament
187
What does the annular ligament resist?
Resists radial head distraction and varus stress
188
What does the anterior oblique ligament resist?
Extension, distraction, varus and valgus
189
Which ligament of the elbow complex is most important for stability?
Medial Collateral Ligament
190
What allows for static stability in the elbow complex?
Bony lockout is most important between: trochlea and trochlear fossa, olecranon, cornoid and radial head and valgus stress
191
How does valgus stress cause bony lockout on the radial head?
Valgus stress compresses the radial head
192
Between the olecranon and the coronoid which is more important for stability?
The coronoid process and coronoid fossa
193
What are the important ligaments that resist supination and pronation?
interosseous and oblique cord.
194
What allows for dynamic stability for flexion in the elbow complex?
Primarily triceps
195
What allows for dynamic stability for extension in the elbow complex?
Primarily brachialis and biceps brachii
196
What allows for dynamic stability for Valgus in the elbow complex?
Muscles that form the common flexor tendon especially pronator teres and Flexor Carpi Ulnaris
197
What allows for dynamic stability for varus in the elbow complex?
Muscles that form the common extensor tendon especially supinator and anconeus
198
What allows for dynamic stability for pronation in the elbow complex?
Primarily the acnoneus, supinator and biceps brachii
199
What allows for dynamic stability for supination in the elbow complex?
Pronator teres and quadratus
200
What is the most important ligament to reinforce posterior slide of the elbow?
Since there is not a posteior capsular ligament there is only the posterior capsule so the tricpes tendon is the most important reinforecement.
201
During throwing what forces are increased during overhand throws in the elbow complex ?
high valgus forces
202
During throwing what side of the elbow complex distracts and which side compresses?
Medial side distracts and lateral side compresses
203
What ligament is important in the elbow complex during throwing and what is a common instability?
Medial collateral ligament and a common instability incolves a lax or torn MCL
204
During throwing what occurs between the radial head and capitulum in the elbow complex ?
Compresses radial head and capitellum which can lead to radial stress fractures and osteochondritis dessicans
205
During throwing what is the effect on the olecranon in the elbow complex ?
Jams medial olecranon against medial side of olecranon fossa
206
what is a fat pad sign? And what is it's significance?
It is when something pushes the fat pad away from surrounding the humerous and it is significant because it means that there is a more serious underlying cause to the swelling in the elbow
207
What is the most common thing done in sports and what is the second most common?
1- running. 2- overhand throw.
208
What will overhand and underhand throwing lead to?
overhand- increased risk of injury. Underhand- decreased risk of injury.
209
What are the 5 phases of overhand throwing?
1. Wind-up. 2. cocking- acceleration 1. 3. Acceleration- part-2. 4. release. 5. Deceleration/ follow through.
210
What happens in the wind-up part of overhand throwing?
balance and preparatory.
211
How is the wind-up part of overhand throwing done?
starts with both feet planted and then pivot on ipsilateral leg, kick with contralateral leg. There are many different styles.
212
What is the risk of injury like during the wind-up phase?
Low.
213
What happens in the cocking phase?
Wind the spring to increase potential energy.
214
How is the cocking phase done?
contralateral forward foot becomes fixed (takes a step forward). Contralateral trunk rotates and chest thrusts forward. Arm externally rotated.
215
What muscles are important in contralateral trunk rotation during the cocking phase?
Abdominal and thigh muscles.
216
What happens to the elbow during the cocking phase?
It is flexed by biceps and brachialis to decrease the risk of injury.
217
What is the serratus anterior doing during the cocking phase?
Stabilizing the scapula and lattisumus dorsi.
218
Where will the tension be during the cocking phase and what will the tension be like?
Pectoralis major, subscapularis, rotator cuff, anteiror GH capsule, Anterior labrum, Ulnar nerve, long head of biceps brachii. Tension will be very high.
219
What part of the shoulder is unstable during the cocking phase and what may occur?
Anterior part is instable and shoulder impingement may occur.
220
What are bankart lesions?
Anterior and SLAP (superior Labial anteior P ).
221
What will a pitcher do to compensate for a sore cuff or impingment?
Switch from overhand throwing to side arm.
222
What will side arm throwing stress?
Elbow.
223
What happens during the acceleration phase when the body moves forward?
contralateral trunk rotation, contralateral flexion and extension as body moves forward.
224
What happens during the acceleration phase at the GH joint?
internal rotation and horizontal adduction.
225
How is the internal rotation and horizontal adduction of the GH joint during acceleration done?***
Latissimus dorsi, pectoralis major and subscapularis forefully move the arm at the GH joint and the shoulder acts as a complex.
226
When throwing a ball it can go 0-80 mph how fast?
80 msec.
227
Throwing a ball this fast places torque where? Causing what?
ON the humerus and this can lead to stress fractures and a single pitch can break the arm.
228
What other stress is placed on the body during the acceleration phase of the overhand throw?
Increased GH compression leading to grinding on the labrum.
229
What will control the position of the humerus during the acceleration phase of the overhand throw?
Cuff.
230
What will cause injury later (from the acceleration phase) of the overhand throw?
Stong contraction but low distraction of the rotator cuff while controling the position of the Humerus.
231
Will impingement of the GH joint still happen during acceleration phase of the overhand throw?
Yes.
232
Acceleration of the overhand throw increases stress where?***
At the elbow.
233
What kind of stress will be on the elbow during the acceleration phase of the overhand throw?
valgus, shear and compression.
234
What happens during internal rotation at the GH joint during acceleration of the overhand throw?
Forearm and hand lag behind as internal rotation at GH begins
235
What is happening with the elbow during accelerationof the overhand throw?
Medial elbow traction with lateral posterior compression leading to olecranon damage.
236
What will late rapid extension during the acceleration of the overhand throw lead to?
Increase stress on biceps traction on the structures attaching to medial epicondyle and MCL
237
The acceleration phase of the overhand throw and increased stress at the elbow may cause what to hypertrophy?
Medial epicondyle and common flexor and biceps later.
238
Medial avulsion from the acceleration phase of the overhand throw are seen amoung who?
Young teens.
239
What is most likely to fracture during the acceleration phase of the overhand throw due to hypertrophy?
Radial head/neck from stress fractures.
240
Late rapid extension during the acceleration phase leads to what?
Increased stress on biceps causing more stress on ulnar nerve.
241
Lateral compression during the acceleration phase leads to what?
Lateral osteochondritis of dissecans.
242
Wha tis osteochondritis of dissecans?
Joint and cartilage lose blood supply. Elbows and knees are most commonly involved.
243
When the medial epicondyle hypertrophies due to increased stress at elbow this causes what?
Avulsion fractures of medial epicondyle and radial head/neck stess fractures.
244
What part of the elbow will have osteochondritis dissecans?
Capitellum.
245
What nerve will be stressed during the acceleration phase of the overhand throw?
ULNAR.
246
Maximum velocity of the arm during overhand throwing occurs when?
Release phase.
247
What happens to the elbow during the release phase?
It is nearly fully extended due to the biceps and brachilais.
248
What is happening with the wrist during release phase?
neutral but flexing.
249
What puts spin on a baseball when throwing it?
Finger action.
250
What faces the plate when throwing a fast, curve and change up?
fast- palm. Curve- palm/hypothernar. Change- released not from fingertips but more towards bases.
251
Why is throwing a curve ball bad?
it delays release and reduces time for recovery and may add supination when pronation should occur (not natural). This also would increase stress on elbow and shoulder.
252
The release phase increases what on the entire upper limb?
Distraction.
253
How hard is it to decelerate a limb after an overhand throw?
2 times the inertia to declerate as it did to accelerate it. OR half as much energy is needed to accelerate an arm than to decelerate it.
254
What happens during deceleration phase?
Internal rotation at GH joint, pronation/ flexion at elbow and wrist flexion.
255
The GH joint will be distracted about how much during overhand throwing?
about 1 inch.
256
What happens with distraction of the GH joint during the deceleration phase?
increased distraction accompanied by horizontal adduction especially posteriorly.
257
What part of the cuff is most vulnerable to injury during the deceleration phase?
posterior/ superior cuff tears and tendonitis. (some supraspinatus but a lot on the posterior capsule
258
What other tissues can be injured during the deceleration phase?
labrum (bankart tears), Cuff, tricpes, latissimus, traps, post deltoid..
259
What will decelerate the arm?
Rotator cuff and it is most vulnerable to injury.
260
Where will increased traction occur at during the deceleration phase?
Suprascapular nerve.
261
Why do pitchers in baseball throw from a mound?
The body will fall forward and this will dissipate energy and decrease injury rates.
262
What will the arm and forearm do during deceleration/ follow through?
Move across body.
263
What are the natural motions of the arm, forearm and wrist during deceleration/ follow through?
internal rotation and pronation and also wrist flexion
264
What delays the follow through phase and disrupts the natural flow of movement ?
supination and this disrupts the natural flow of movement.
265
What happens with the body during deceleration/ follow through?
Body pivots at hip of stance limb; hip/knee/ankle torque leads to occasional injury.
266
Why will the body pivot at hip stance limb during deceleration if this leads to hip/knee/ankle injuries occasionally?
To decrease arm stress.
267
What is the final position of the upper limb at the end of follow through?
Internally rotated and adducted at the GH and pronated and flexed at the elbow.
268
The end of follow through might increase tension on what?
Suprascapular and axillary nerve.
269
When will there be less throwing velocity?
When lower extremities are not in contact with ground and not able to use lower limb muscles.
270
What is the convex rule?
Direction of slide is opposite the direciton of roll. Angular movement is opposite of slide and same direction of roll.
271
What is the Concave rule?
Direction of slide is the same as roll. Angular movement is in the same direction as slide and roll.
272
With the convex and concave rules when will the motions be opposite?
Only convex will slide be opposite as roll.
273
What is the top of part of the distal phalanx called?
Ungual tuft.
274
What row of carpal bones is more stable?
Proximal less stable and distal is more stable.
275
Name the stable bones of the wrist and hand?
Trapezium, trapezoid, capitate, hamate, 2 and 3 metacarpals.
276
How many phalanges will each hand have?
14 of them.
277
How many sesamoid bones are on each hand?
two.
278
What is the keystone bone of the wrist?
Capitate.
279
What is the bony meniscus of the wrist?
Proximal row.
280
What is the purpose of the bony meniscus aka proximal row of carpal bones?
Increase mobility and act as a group.
281
What is the main weight bearing carpal bone?
Scaphoid.
282
What carpal bone is most often fractured?
Scaphoid.
283
What is the most unstable carpal bone?
Lunate.
284
How many carpal rows are there and how many carpal columns are there?
2 rows and 3 columns.
285
What is the midcarpal complex?
The joint complex between the proximal and distal carpal rows.
286
Name 2 more wrist complex joints?
Radiocarpal and ulnocarpal joint complexes.
287
What is the pattern of stability like in the wrist?
Stability increases from proximal to distal (besides thumb).
288
Name the arches of the hand and where they are at?
1. Transverse- makes the carpal tunnel. 2. Longitudinal- from middle carpal to end of third finger. 3. Oblique- thumb to other fingers.
289
What will the 3 arches of the hand improve?
Grip, flexibility, dexterity, wrist/forearm communicatino with vessels.
290
The transvere arch = what?
Carpal gutter.
291
What is found in the carpal tunnel?
Flexor tendons, median nerve. NO ARTERIES OR VEINS.
292
How does the median nerve travel in the carpal tunnel and why is this significant?
Median nerve becomes more superficial in the carpal tunnel and the tendons are under it. Repetitive motions cause constant movement and can cause issues with the nerve
293
what covers the superior part of the carpal tunnel?
The flexor retinaculum.
294
What are the 3 positions that can compress the carpal tunnel?
Flexion, Extension, ulnar deviation aka adduction.
295
What makes up the tunnel of Guyon?
Pisiform, hamate.
296
What forms the bottom or floor of the tunnel of guyon?
Pisohamate ligament.
297
What travels through the tunnel of guyon?
Ulnar nerve, artery and vein.
298
Will the tunnel of guyon be part of the carpal tunnel?
No.
299
What bone moves in the forearm?
The radius.
300
When will the radius be parallel and when will it cross the ulna?
Parallel- supinated. Cross- pronated.
301
What is the shape of the radius?
Crank.
302
The forearm biomechanics and anatomy has a strong influence on what?
pronation and supination. At both R-U joints
303
The radial head spins on what?
Capitellum.
304
How will the distal radius move?
Swing/ slide on the head of the ulna.
305
Where is the ulnar head found?***
Distally
306
Where is the radial head found?***
Proximally
307
What holds the radial head in place?
Annular ligament.
308
What will stabilize the radius?
Interosseus membrane and the oblique cord. (if too tight, limits pronation)
309
What is another name for the scaphoid?
Navicular bone.
310
What is the main weight bearing part of the wrist?
Carpal surface of the radius.
311
What are the main weight bearing carpal bones?
Mainly- SCAPHOID. a liitle from; lunate, and triquetral.
312
Which forearm bone will have what % of the weight bearing load?
Radius- 60-90%. Ulna- 10-40%.
313
What is the scaphoid and 4 X rule?
scaphoid fractures are about 80-90% of carpal fractures because the force on a fall to an outstretched hand causes a 4x increase of force on the scaphoid ie: 100lbs of force on fall = 400 lbs on scaphoid.
314
What is the TFC?
Triangular fibrocartilage complex.
315
The TFC is important in what motion?
Supination and pronation.
316
Where is the TFC aka triangular fibrocartilage complex located at?
Ulnocarpal joint and distal Radio-ulnar joint aka DRUJ.
317
Where will the TFC disc sweep under?
Ulnar head.
318
The hand moves with what?
The radius.
319
What does the TFC moves with?***
the radius and all other wrist motions
320
What is TFCC?
Ligaments and cartilage of the DRUJ joint not just the cartilage.
321
What are the 2 main arterial blood supplies to the hand?
Radial and ulnar arteries.
322
What happens to the radial and ulnar arteries of the hand?
There form a deep and a superficila arch and have many anastomoses and collateral circulation.
323
What is Volar?
another name for palmer or anterior hand.
324
What is the function of the synovial tendon sheaths?
To guide, support, and lubricate the tendons.
325
The thumb and pink synovial tendon sheaths commonicate with what?
The palm.
326
Where will hand infections most commonly happen?
Finger creases
327
Where are synovial tendon sheaths most superficial and what is it's significance?
The sheaths are most superficial at the finger creases and the synovial fluid is connected all the way up the arm so infections can travel up this pathway.
328
What is mesotenon?
Mesentery of the hand for vessels, nerves, and is necessary for tendon survival.
329
what sensory area is supplied by the median nerve on the palmer?
Most of thumb besides lateral part, palm and fingers until middle of the 4th finger.
330
what sensory area is supplied by the ulnar nerve on the volar surface?
Palm and fingers on medial side up to the middle of the 4th finger
331
what sensory area is supplied by the radial nerve on the volar surface?
only lower lateral part of thumb
332
what sensory area is supplied by the median nerve on the dorsal surface?
tips of the 2nd, 3rd and half of the 4th fingers
333
what sensory area is supplied by the ulnar nerve on the dorsal surface?
back of hand and fingers medially up to the middle of the 4th finger
334
what sensory area is supplied by the radial nerve on the dorsal surface?
thumb, back of hand and fingers up to the middle of the 4th finger (besides the distal phalanges of the 2nd 3rd and half of the 4th digitis).
335
Where is the radial nerve pure patch?
Dorsal: at the web of the hand btw the 1st and 2nd digit
336
Where is the median nerve pure patch?
Anterior: On the DIP of the 2nd digit
337
Where is the ulner nerve pure patch?
Dorsal: over the Hammate area (dorsal part of the 5th digit)
338
Where is the segmental dermatomes of C6,7 and 8?
C6 = lateral hand with only the thumb and 2nd digits C7 = middle part of hand and 3rd digit C8 = Medial hand and 4-5th digits
339
What is the C7 Pure patch
tip of middle finger
340
What is the C6 Pure Patch?
the DIP of the thumb
341
What is the C8 Pure Patch?
The DIP of the 5th digit
342
What is a site of early sensory loss from carpal tunnel?
The dorsal distal phalanges of 2nd 3rd and half of the 4th digits.
343
What will the proximal carpal row do during wrist flexion and extension?
Flexion- dorsal slide and palmer roll. Extension- palmer slide and dorsal roll and proximal.
344
With wrist flexion and extension which row of carpals will move more/
Flexion- distal row. Extension- proximal row.
345
Which carpal bone is the oddball when it comes to flexion and extension and why?
Scaphoid moves away from lunate during extension and S-L ligament tears (SLAC lesion).
346
What happens with the scaphoid during abduction and with extension and why is this important?
Scaphoid is impinged with abductin and extension and this is important with fractures.
347
is there more ulnar or radial deviation ROM? Why?
More Ulnar deviation (30 degrees) than radial deviation (20 degrees) because the radius is longer and so the radial styloid blocks more motion.
348
What is Madelung's deformity?
Abnormally long Ulna (+ulnar variance) caused by distal radial growth arrest
349
What wrist ligament is most commonly torn?
Scapholunate.
350
What ligament helps keep the carpals together?
Radiate.
351
Where else in the body is there a radiate ligament?
Ribs
352
What ligament resists extension of the wrist?
Lunotriquetral.
