-
AC joint:
acromioclavicular joint-Planar joint of acromion process of scapula and lateral end of clavicle.
-
SC joint:
sternoclavicular joint-Joint between medial end of clavicle and manubrium of sternum.
-
How many muscles attach to the scapula?
17
-
S/T joint:
scapulothoracic joint-A false joint (no joint capsule) where the scapula makes contact with the posterior wall of the thorax.
-
shoulder joint movements-
(glenohumeral joint) flexion/extension, medial/lateral rotation, abduction/adduction, horizontal adduction/abduction, circumduction
-
What are the segments of the deltoid muscle?
- Anterior-
- Middle-
- Posterior-
-
What is the primary action of the deltoid muscle (all three segments)?
Shoulder abduction
-
What is the relationship between the anterior and posterior portions of the deltoid muscle?
They are antagonists in all actions except abduction, where they act synergistically.
-
What is the origin of the deltoid muscle?
- Lateral 1/3 of clavicle-
- Acromion process of scapula-
- Spine of scapula-
-
What is the insertion of the deltoid muscle?
Deltoid tuberosity of the radius
-
What is the collective action of all three segments (anterior, middle, and posterior) of the deltoid muscle?
Abduction of the shoulder
-
What are the actions of the anterior deltoid muscle fibers?
- Shoulder-
- flexion
- internal (medial) rotation
- horizontal adduction
-
What are the actions of the middle deltoid muscle fibers?
Shoulder abduction
-
What are the actions of the posterior deltoid muscle fibers?
- Shoulder-
- extension
- external (lateral) rotation
- horizontal abduction
-
What are the divisions/segments of the trapezius muscle?
- Upper fibers-
- Middle fibers-
- Lower fibers-
-
Describe the upper portion of trapezius muscle.
Fibers run from the occipital protuberance, down the ligamentum nuchae, to the cervical spine.
-
Describe the middle portion of the trapezius muscle.
Fibers run from the upper thoracic spine out to the acromion process.
-
Describe the lower portion of the trapezius muscle.
Fibers run from the middle thoracic spine down to the spinous process of T12.
-
What is the origin of the trapezius muscle?
- External occipital protuberance-
- Medial portion of superior nuchal line-
- Ligamentum nuchae-
- Spinous processes of C7-T12
-
What shape does the origins of the trapezius muscle make?
"T" shape
-
The origin of the trapezius muscle is the same as the insertion of what muscle?
Deltoid muscle
-
What is the insertion of the the trapezius muscle?
- Lateral 1/3 of clavicle
- Acromion-
- Spine of scapula-
-
Which portion(s) of the trapezius muscle have both unilateral and bilateral movements?
Upper fibers (only)
-
What are the unilateral movements of the upper fibers of the trapezius muscle?
- Lateral flexion of head/neck - to same side
- Rotation of head/neck - to opposite side
- Elevation of scapula at S/T joint
- Upward rotation of scapula at S/T joint
-
What are the bilateral movements of the upper fibers of the trapezius muscle?
Extension of head/neck
-
What are the actions of the middle fibers of the trapezius muscle?
- Retraction (adduction) of scapula at S/T joint-
- Stabilization of scapula at S/T joint-
-
What are the actions of the lower fibers of the trapezius muscle?
- Depression of scapula at S/T joint-
- Upward rotation of scapula at S/T joint-
-
ligamentum nuchae:
A fin-like sheet of fascia that runs sagittally from the occipital protuberance to C7.
-
superior nuchal line:
A line extending outward from the external occipital protuberance.
-
intertubercular groove:
A pencil-width gap between the greater and lesser tubercles of the humerus that houses the tendon for the long head of the biceps brachii muscle.
-
crest of lesser tubercle:
A vertical ridge running inferiorly from the lesser tubercle.
-
thoracolumbar aponeurosis:
A dense, flat, diamond-shaped tendon stretching from the iliac crest to the lower thoracic vertebrae (TCA).
-
What is the origin for the latissimus dorsi muscle?
- Inferior angle of scapula-
- Spinous processes of T6 to T12-
- Last 3-4 ribs-
- TCA-
- Posterior iliac crest-
-
What is the insertion of the latissimus dorsi muscle?
Intertubercular groove of humerus-
-
What is the nickname for the latissimus dorsi muscle, and why?
- "Handcuff muscle"-
- Because the actions for this muscle mimic those of someone in handcuffs.
-
What are the actions of the latissimus dorsi muscle?
- Extension of the shoulder-
- Internal (medial) rotation of the shoulder-
- Adduction of the shoulder-
-
complete synergist:
Two or more muscles with exactly the same movements.
-
What muscle is a complete synergist to the latissimus dorsi muscle?
Teres major muscle-
-
What is the nickname for the tares major muscle?
"lats little helper"
-
What is the origin for the tares major muscle?
Inferior angle & lower 1/3 lateral border of scapula
-
What is the insertion for the teres major muscle?
Lesser tubercle crest of humerus-
-
What are the actions of the teres major muscle?
- Extension of the shoulder-
- Internal (medial) rotation of the shoulder-
- Adduction of the shoulder-
-
Name the rotator cuff muscles.
- Supraspinatus-
- Infraspinatus-
- Teres minor-
- Subscapularis-
-
What movement do all of the rotator cuff muscles share in common?
Stabilization of the head of the humerus in the glenoid cavity.
-
All but one of the rotator cuff muscles attach at a common insertion site. What is that insertion site (a), and which muscle is the exception(b)?
- a. Greater tubercle of humerus-
- b. Subscapularis-
-
Where does the subscapularis muscle insert?
Lesser tubercle of humerus-
-
What are the actions of the supraspinatus muscle?
- Abduction of shoulder-
- Stabilization of head of humerus in glenoid cavity-
-
What are the actions of the infraspinatus muscle?
- Adduction of shoulder-
- External (lateral) rotation of shoulder-
- Stabilizes head of humerus in glenoid cavity-
-
What is the origin of the teres minor muscle?
Upper 2/3 lateral border of scapula-
-
What are the actions of the teres minor muscle?
- Adduction of shoulder-
- External (lateral) rotation of shoulder-
- Stabilizes head of humerus in glenoid cavity-
-
What are the actions of the subscapularis muscle?
- Internally (medially) rotates shoulder-
- Stabilizes head of humerus in glenoid cavity-
|
|
