Unit 8 Anatomy - Glenohumeral joint articulations and movements/ Neurovasculars

glenohumeral joint

-articulation between glenoid fossa and humeral head -synovial -ball and socket -most mobile joint -bone instability

3 glenohumeral ligaments

-capsular -anterior 1. superior limits: -ER -ADD 2. middle limits -ER 3. inferior limits -ER -ABD -also has posterior band

what does externally rotating during abduction do to the subacromial space?

-clears greater tubercle -provides articular surface

synovium of the glenohumeral joint

-extensive synovium -tendon of biceps brachii, long head within synovium

supraspinatus injury

-fibrocartilage formation and calcification in tendon -more brittle tendon - partial or complete avulsion of tendon

joint capsule

-fibrous attachment: anatomical neck and rim of glenoid fossa -inferior aspect of capsule is weakest: axillary recess -dislocation occurs here when the axillary recess is brought to the front (anterior) of the shoulder

glenohumeral movements

-flexion/extension -horizontal AB/ADduction -ab/adduction -IR/ER

subacromial bursitis

-inflammation of bursa - develops secondarily to injury, impingement and so on -reduces space for supraspinatus tendon

what do the dynamic ligaments of the rotator cuff do?

-stabilize and encapsulate glenohumeral joint -allow muscles with larger lever arms to move humerus

bursa within the glenohumeral joint

-subacromial bursa -subdeltoid bursa -subcoracoid bursa reduces friction - fluid filled

match the artery with its parent -suprascapular artery -profunda brachii artery -posterior humeral circumflex artery -circumflex scapular artery -thyrocervical trunk

-suprascapular artery - thyrocervical trunk -profunda brachii artery - brachial a -posterior humeral circumflex artery - axillary a -circumflex scapular artery - subscapular a -thyrocervical trunk - subclavian a

why is the glenohumeral joint instable? what do we have that helps with stabilty?

-the glenoid fossa only covers 1/4-1/3 of head of humerus - we have a glenoid labrum that improves congruency and reduces compressional stress

Order the borders and contents of the subacromial space from inferior to superior (1 = most inferior, 6 = most superior). Head of humerus (border) Superior joint capsule Coracoacromial arch (border) Bursae Supraspinatus Long head of biceps brachii tendon

1. Head of humerus (border) 2. Long head of biceps brachii tendon 3. Superior joint capsule 4. Supraspinatus 5. Bursae 6. Coracoacromial arch (border)

Match the scapulothoracic motions with their corresponding glenohumeral motions. 1. Scapulothoracic adduction/retraction 2. scapulothoracic anterior tip 3. scapulothoracic upward rotation 4. scapulothoracic abduction/protraction a. Glenohumeral external rotation b. Glenohumeral extension c. Glenohumeral horizontal adduction d. Glenohumeral abduction

1. Scapulothoracic adduction/retraction = a. Glenohumeral external rotation 2. scapulothoracic anterior tip = b. Glenohumeral extension 3. scapulothoracic upward rotation = d. Glenohumeral abduction 4. scapulothoracic abduction/protraction = c. Glenohumeral horizontal adduction

match the bnerves and arteries that run together in the upper brachium 1. median nerve 2. musculocutaneous nerve 3. radial nerve a. brachial artery b. doesnt run with a major artery c. profunda brachii artery

1. median nerve - a 2. musculocutaneous nerve - b 3. radial nerve - c

Order the major nerves in the upper brachium from anterior to posterior (1 = most anterior, 4 = most posterior). musculocutaneous nerve radial nerve ulnar nerve median nerve

1. musculocutaneous nerve 2. median nerve 3. ulnar nerve 4. radial nerve

Describe the order of structures from proximal to distal (1 = most proximal, 6 = most distal). nerve roots C4-C6 innervates infraspinatus under scapular spine innervates supraspinatus underneath transverse scapular ligament suprascapular nerve

1. nerve roots C4-C6 2. suprascapular nerve 3. underneath transverse scapular ligament 4. innervates supraspinatus 5. under scapular spine 6. innervates infraspinatus

match the rotator cuff muscle to its innervation 1. subscapularis 2. teres minor 3. infraspinatus a. axillary nerve b. upper and lower subscapular nerves c. suprascapular nerve

1. subscapularis - b 2. teres minor - a 3. infraspinatus - c

what are the elbow flexors?

Biceps -long head -short head brachialis brachioradialis

Which of the following ONLY has action at the elbow? a. Biceps brachii b. Brachioradialis c. Brachialis

Brachialis

Which part of the pectoralis major has both glenohumeral and scapulothoracic actions? Clavicular part Sternal part

Sternal part

Which of the following is NOT a benefit of appropriate scapulohumeral rhythm? a. Allows you to maintain a neutral scapular position throughout humeral motion b. Allows you to maintain length-tension relationships of rotator cuff muscles. c. Allows you to reduce motion at the glenohumeral joint d. Allows you to decrease impingement at the glenohumeral joint

a. Allows you to maintain a neutral scapular position throughout humeral motion

Which head of the biceps brachii has actions at the glenohumeral and elbow joints? a. Both b. Long head c. Short head

a. Both

The glenoid labrum performs all of the following EXCEPT a. Decreases contact area of the head of the humerus with the glenoid cavity b. Covers one-fourth to one-third of the humeral head c. Improves congruency d. Reduces compressional stress

a. Decreases contact area of the head of the humerus with the glenoid cavity

All three glenhumeral ligaments (superior, middle, and inferior) limit which humeral motion? a. External rotation b. Abduction c. Adduction d. Internal rotation

a. External rotation

You now know where the axillary recess is and that it is the weakest part of the joint capsule. This is clinically important because when the axillary recess is positioned anteriorly, the humeral head can push into it, potentially resulting in shoulder dislocation. Consider then, which of the following humeral positions would place the axillary recess anterior? a. Humeral external rotation and horizontal abduction b. Humeral external rotation and horizontal adduction c. Humeral internal rotation and horizontal adduction d. Humeral internal rotation and horizontal abduction

a. Humeral external rotation and horizontal abduction

Between what two structures would you look to find the triangular space? a. Teres minor and major b. Triceps long and lateral heads c. Teres major and triceps long head

a. Teres minor and major

is the biceps brachii in a "stretched out" position when your arm is.. a. pronated b. supinated

a. pronated -its wrapping around the radial tuberosity in this position

deltoid action

anterior deltoid -flex -IR -horizontally adduct -add/abduction middle delt -abduction posterior delt -extend -ER -horizontally abduct -adduction/abduction

coracohumeral ligament

attachment: -coracoid process -greater and lesser tuberosity -capsular -spans bicipital groove limits -inferior translation -adduction

coracoacromial ligament

attachments: (attaching one bone to the same bone - createse a roof for the coracoacromial arch) -coracoid process -acromion -extrinsic -roof of coracoacromial arch limits -superior movement of humerus

Which of these muscles is on the same side of the scapular spine as the teres minor? a. Anterior deltoid b. Infraspinatus c. Supraspinatus

b. Infraspinatus

Which rotator cuff muscle is NOT a glenohumeral external rotator? a. Infraspinatus b. Subscapularis c. Teres minor

b. Subscapularis

Which rotator cuff muscle is hidden by the scapula when looking at the posterior thorax? a. teres minor b. subscapularis c. supraspinatus d. infraspinatus

b. subscapularis

quadrangular space: what are the borders and its contents?

border -teres minor (superior) -teres major (inferior) -triceps long head (medial) -humerus (lateral) contents -posterior humeral circumflex artery -axillary nerve

triceps haitus: what are the borders and its contents?

borders -teres major (superior) -humerus (lateral) -triceps long head (medial) contents -profunda brachii arter -radial nerve

triangular space: what are the borders and its contents?

borders -teres minor (superior) -teres major (inferior) -triceps long head (lateral) contents -circumflex scapular artery

what is considered the single-joint workhorse of elbow flexors?

brachialis

Between what two structures would you look to find the triceps hiatus? a. Teres minor and infraspinatus b. Triceps long head and teres major c. Humerus and triceps long head

c. Humerus and triceps long head

Which triceps head is deep to the other two? a. Long head b. Anterior head c. Medial head d. Lateral head

c. Medial head

what does the musculocutaneous nerve innervate?

coracobrachialis bicepc brachii brachialis

Which cutaneous region of the upper extremity is innervated by a renamed musculocutaneous nerve? a. Medial antebrachium b. Medial brachium c. Top of shoulder d. Lateral antebrachium

d. Lateral antebrachium

If your patient has lost feeling on the lateral portion of the brachium, which nerve may be affected? a. Medial antebrachial cutaneous nerve b. Lateral brachial cutaneous nerve c. Lateral antebrachial cutaneous nerve d. Radial nerve

d. Radial nerve

Which of the following has action at more joints than just the elbow? a. Triceps brachii lateral head b. Tripceps brachii medial head c. Anconeus d. Triceps brachii long head

d. Triceps brachii long head

T/F all of pectoralis major has action at the scapula

false - only the sternal part of the pectoralis major because it attaches at the axial skeleton

what is the most mobile joint in the body?

glenohumeral joint

if a muscle attaches from the humerus to the scapula, which bone will it move?

it would move the one with less inertia... so the humerus

what nerve does the musculocutaneous nerve turn into ?

lateral antebrachial cutaneous

what does the musculocutaneous nerve branch from?

lateral cord

which muscles are considered "best friends" because they have common insertion and the same actions at the GH joint?

latissimus dorsi and teres major

If scapulohumeral rhythm is dysfunctional and there is too much scapular upward rotation with glenohumeral abduction, would subacromial impingement become more or less likely? Less More

less - More scapular upward rotation would increase the subacromial space, making impingement less likely.

which biceps brachii head runs through the bicipital groove?

long head

scapulohumeral rhythm

movements of the humerus and shoulder girdle are coordinated for many movements -reduce ROM necessary at glenohumeral joint -keep rotator cuff muscles at optimal length-tension relationship

subacromial space

narrow space between scapula (coracoacromial arch) and head of humerus - superior border: inferior surface of coracoacromial arch -bursae -supraspinarus and upper margins of infraspinatus and subscapularis -superior joint capsule -long head of biceps brachii tendon -inferior border: head of the humerus

what does the radial nerve branch from?

posterior cord

Based on most similar muscle action, pair the deltoid regions and rotator cuff muscles. posterior deltoid anterior deltoid middle deltoid a. infraspinatus b. supraspinatus c. subscapularis

posterior deltoid - a. infraspinatus anterior deltoid - c. subscapularis middle deltoid - b. supraspinatus

match the structure to the space where it can be found posterior humeral circumflex a suprascapular nerve radial nerve circumflex scapular a a. triangular space b. not in one of the spaces c. quadrangular space d. triceps haitus

posterior humeral circumflex a =c. quadrangular space suprascapular nerve = b. not in one of the spaces radial nerve = d. triceps haitus circumflex scapular a = a. triangular space

rotator cuff muscles

stabilize in multiple directions -anterior: subscapularis -superior: supraspinous - posterior: infraspinatus - posterior: teres minor

what nerve does the radial nerve turn into?

superficial radial deep radial -posterior interosseous

what ligament makes up the scapular notch?

superior transverse scapular ligament

to what must a muscle attach in order to move the shoulder girdle?

the axial skeleton

which has more inertia, the humeris (UE) or the scapula (thorax)?

the scapula

what muscles does the radial nerve innervate?

triceps anconeus brachioradialis

what are the elbow extensors?

triceps brachii -long head -medial head -lateral head anconeus

After a manual muscle test, you determine that your patient is unable to effectively abduct their glenohumeral joint. First, identify the muscles that are weak. Next, determine what shoulder girdle muscles might compensate in order to lift the glenoid cavity superiorly. Spend some time considering this before moving forward to see the answer.

weak muscles may be: -Supraspinatus -Middle deltoid -Anterior, posterior deltoid if >60 deg abducted -Pectoralis major (clavicular) if > 90 deg abducted (Note that anterior, posterior deltoid and pectoralis major are unlikely to contribute to abduction in this patient because of limited range of motion with weakness.) Shoulder girdle muscles that would compensate are upward rotators of the scapula: -Serratus anterior, inferior -Trapzeius- I, II, IV

can a muscle move both the glenohumeral joint and the shoulder girdle?

yes, but it must attach to the axial skeleton