lecture 42 joints and muscles

what is the pectoral girdle formed by?

clavicle (collar bone) and scapula (shoulder blade)

what does the clavicle behave as?

strut

what joint attaches the upper extremity to the axial skeleton at a single point?

sternoclavicular joint

what is the bone of brachium or arm?

humerus

what is the lateral antebrachial bone?

radius

what is the medial antebrachial bone?

ulna

what is the proximal row of carpal bones lateral to medial?

scaphoid, lunate, triquetrum, pisiform

what is the distal row of carpal bones lateral to medial?

trapezium, trapezoid, capitate, hamate

there are 3 phalanges per digit expect...

the pollex which has 2

the upper extremity is primarily used for ___ not ___

manipulation, not ambulation

how many primary anatomic joints or sets of joints are associated with the upper extremity?

ten

of the 10 primary anatomic joints associated with the upper extremity, how many position the upper limb?

7

of the 10 primary anatomic joints associated with the upper extremity, how many are responsible for fine motor skills of the hand?

3

what are the upper limb joints that position the limb?

sternoclavicular joint, acromioclavicular joint, glenohumeral joint, elbow joint with humeroradial, humeroulnar, and proximal radioulnar, distal radioulnar joint, radiocarpal joint, midcarpal joint

what are the upper limb joints that are responsible for fine movement of the hand?

carpometacarpal joint, metacarpophalangeal joint, interphalangeal joint

the shoulder joint complex includes ___ anatomic joint(s) and ___ physiologic joint(s)

3, 1

what joints form the shoulder joint complex?

sternoclavicular joint, acromioclavicular joint, glenohumeral joint, scapulothoracic joint

the medial end of the clavicle articulates with the manubrium of the sternum to form a ____ type joint

plane

between the medial end of the clavicle and manubrium of the sternum, there is an articular disc of fibrocartilage that subdivides the joint into...

2 synovial cavities

dividing the sternoclavicular joints into two synovial cavities enables more motion so the joint behaves like a...

ball and socket joint

the sternoclavicular joint is a strong, stable joint reinforced by what?

anterior and posterior sternoclavicular ligaments, interclavicular ligament, and costoclavicular ligament

what does the costoclavicular ligament bind?

first costal cartilage to inferior surface of clavicle

the acromioclavicular joint is a ___ joint that is formed as the lateral end of the clavicle articulates with the acromion process of the scapula

plane

what surrounds the acromioclavicular joint?

loose capsule

what is movement at the acromioclavicular joint limited by?

proximal and distal ligaments

what reinforces the superior aspect of the acromioclavicular joint?

acromioclavicular ligament

what does the coracoclavicular ligament consist of?

two ligaments separated by a bursa

what is the acromioclavicular joint strengthened and greatly stabilized by?

bipartite coracoclavicular ligament (comprised of 2 ligaments)

what are the two ligaments making up the bipartite coracoclavicular ligament?

conoid ligament and trapezoid ligament

where is the conoid ligament located?

posteromedially

where is the trapezoid ligament located?

anterolaterally

the glenohumeral joint is a ___ joint formed by the head of the humerus and glenoid fossa of the scapula

ball and socket

what allows for the greatest ROM of any joint?

glenohumeral joint

why does the glenohumeral joint possess little structural stability?

due to relatively shallow glenoid fossa and rounded humeral head

what allows for coupled movement of the glenohumeral joint?

articular capsule is relatively lax and has two apertures

>90% of glenohumeral dislocations occur in an ____ direction

anterior and inferior

what are the strengthening/stabilizing features of the glenohumeral joint?

glenoid labrum, coracoacromial ligament, glenohumeral ligaments, and rotator cuff

what is the glenoid labrum?

fibrocartilaginous lip attached to the margin of the glenoid fossa

what helps deepen the glenoid fossa?

glenoid labrum

what completes a protective arch over the head of the humerus by extending the protection from the acromion process?

coracoacromial ligaments

how do the glenohumeral ligaments stabilize the glenohumeral joint?

reinforce the anterior portion of the capsule

what are a group of four mm that surround the shoulder joint and pull the head of the humerus into the glenoid fossa?

rotator cuff mm

the rotator cuff mm are ___ stabilizers

dynamic

what are the rotator cuff mm?

supraspinatus, infraspinatus, teres minor, subscapularis mm

what kind of joint is the scapulothoracic joint?

physiological joint

the scapulothoracic joint is formed by articulation of the...

anterior aspect of the scapula and subscapularis m with the thoracic cage

what does the scapulothoracic joint play a role during?

compound glenohumeral movements, particularly those including flexion and abduction beyond 90 degrees

alterations in movement of scapulothoracic joint occur in what?

scapulothoracic adhesions, adhesive capsulitis, and primary and secondary impingement

what is the subdeltoid joint?

physiologic articulation involving the inferior surface of the acromion, coracoacromial ligament, rotator cuff, and long head of biceps tendon

the inferior surface of the acromion, coracoacromial ligament, rotator cuff, and long head of biceps tendon involved in the subdeltoid joint form a concave structure that parallels the...

convex humeral head

what does the subdeltoid join

list physiological joints

scapulothoracic joint, subdeltoid joint, subacromial joint

what does the subdeltoid joint provide for the head of the humerus?

gliding surface, especially during abduction, coupled movement-glide and roll

what supports the premise that the subdeltoid joint plays a role in complex shoulder motions?

degenerative changes occur on the underside of the acromion process (spurring)

the subacromial joint is formed by articulation of the...

coracoacromial ligament and head of humerus

what is the subacromial joint anterior to?

subdeltoid joint

the joint space of the subacromial joint is filled primarily by the...

subacromial bursa and tendon of supraspinatus

what does the subacromial joint play a role during?

compound glenohumeral movements incorporating flexion forwards or in scaption

the elbow joint is a group of ___ unique joints enclosed within the same joint capsule

3

what three joints make up the elbow joint?

humeroulnar, humeroradial, proximal radioulnar

what type of joint is the humeroulnar joint?

hinge joint

what is the humeroulnar joint strengthened by?

tripartite ulnar or medial collateral ligament of the elbow

what type of joint is the humeroradial joint?

limited ball and socket joint

in the humeroradial joint, the head of the radius rides against the ___ of the humerus

capitulum

what is the humeroradial joint stabilized by?

radial or lateral collateral ligament of the elbow

what kind of joint is the proximal radioulnar joint?

pivot joint

in the proximal radioulnar joint, the head of the radius articulates with the...

radial notch of the ulna

what is included in the proximal radioulnar joint and encircles the head of the radius?

annular ligament

what type of joint is the distal radioulnar joint?

pivot joint

in the distal radioulnar joint, the ____ glides around the head of the ulna

ulnar notch of the radius

at the distal radioulnar joint, what attaches to both the radius and the ulna and allows rotation of the radius?

fibrocartilage articular disc

the distal radioulnar joint allows for what movement?

supination and pronation

what type of joint is the radiocarpal joint?

condyloid joint

in the radiocarpal joint, the distal end of the radius and its associated articular disc articulate with what?

scaphoid and lunate

what are the primary movements of the radiocarpal joints? what other movements can occur?

adduction and extension of the hand, flexion and abduction

what is the carpal bone that is most likely to be fractured?

scaphoid

during a FOOSH (fall on outstretched hand), the hand is typically adducted and extended and the ___ is exposed

scaphoid (fo)

what type of joint is the midcarpal joint?

compound gliding joint

what is the midcarpal joint formed between?

proximal and distal rows of carpals

what does the midcarpal joint compliment the movement of?

radiocarpal joint

what are the primary movements of the midcarpal joint? what other movements can occur?

abduction and flexion of hand, some extension and adduction

what kind of joints are the carpometacarpal joints?

plane joints

what are the carpometacarpal joints bound by?

single, common articular capsule which permits little movement

the carpometacarpal joint forms when what bones articulate?

distal carpals and 2-5th metacarpals

the carpometacarpal joint of the pollex is a saddle joint formed by the articulation of the...

trapezium and base of 1st metacarpal bone

what types of motion does the carpometacarpal joint of the pollex allow for?

flexion, extension, abduction, adduction, and opposition

what type of joints are the metacarpophalangeal joints?

condyloid joints

the metacarpophalangeal joints are formed as what bones articulate?

head of metacarpals and proximal ends of the proximal phalanges

what type of movement does the metacarpophalangeal joints allow for?

flexion and extension, abduction and adduction can occur when the joints are extended

what type of joints are interphalangeal joints?

hinge joints

what do interphalangeal joints occur between?

proximal and middle phalanges and between middle and distal phalanges of digits II through V

the pollex only has a single interphalangeal joint between the ___ and ___ phalynx

proximal and distal

what are the interphalangeal joints stabilized by?

medial and lateral collateral ligaments

what type of movement is prevented in the interphalangeal joints by the medial and lateral collateral ligaments?

abduction and adduction