Shoulder Anatomy
GLENOHUMERAL JOINT
Description/Articulations
· Ball and socket joint
· Joint is made of the head of the humerus
articulating with the glenoid cavity of the scapula
Movements
· Flexion
· Extension
· Abduction
· Adduction
· Rotation
· Circumduction 1
Function
· Allows for movement of the arm
Parts of the Glenohumeral Joint
a. Synovial cavity, articular capsule
i. Shoulder capsule surrounds the
ball-and-socket part of the shoulder joint
ii. Capsule separates the joint from the rest of
the body
iii. Capsule contains synovial fluid
iv. Contains ligaments that keep the shoulder joint in the proper position1
b. Accessory ligaments
i. Coracohumeral ligament
1. Crosses from the coracoid process to the neck of the humerus
ii. Coracoiacromial ligament
1. Crosses above the joint between the acromion process and the coracoid process
iii. Glenohumeral ligament
1. Three thicker longitudinal sets of fibers on the anterior side of the capsule
2. Extends from the humerus to the margin of the glenoid cavity
iv. Transverse humeral ligament
1. Lateral, transverse, fibrous thickening of the joint capsule
2. Crosses between the greater and lesser tubercles
3. Lies anterior to the biceps brachii tendon, holding it in place2
c. Glenoid labrum
i. Is a fibrocartilage ring located in the rim of the glenoid cavity
ii. Joint capsule attaches to the glenoid labrum2
d. Burseae
i. Subscapular
1. Opens into the joint capsule
ii. Subdeltoid
iii. Subacromial
1. Located near the joint cavity
2. Separated from the cavity by the joint capsule
iv. Subcoracoid 2
Description/Articulations
· Ball and socket joint
· Joint is made of the head of the humerus
articulating with the glenoid cavity of the scapula
Movements
· Flexion
· Extension
· Abduction
· Adduction
· Rotation
· Circumduction 1
Function
· Allows for movement of the arm
Parts of the Glenohumeral Joint
a. Synovial cavity, articular capsule
i. Shoulder capsule surrounds the
ball-and-socket part of the shoulder joint
ii. Capsule separates the joint from the rest of
the body
iii. Capsule contains synovial fluid
iv. Contains ligaments that keep the shoulder joint in the proper position1
b. Accessory ligaments
i. Coracohumeral ligament
1. Crosses from the coracoid process to the neck of the humerus
ii. Coracoiacromial ligament
1. Crosses above the joint between the acromion process and the coracoid process
iii. Glenohumeral ligament
1. Three thicker longitudinal sets of fibers on the anterior side of the capsule
2. Extends from the humerus to the margin of the glenoid cavity
iv. Transverse humeral ligament
1. Lateral, transverse, fibrous thickening of the joint capsule
2. Crosses between the greater and lesser tubercles
3. Lies anterior to the biceps brachii tendon, holding it in place2
c. Glenoid labrum
i. Is a fibrocartilage ring located in the rim of the glenoid cavity
ii. Joint capsule attaches to the glenoid labrum2
d. Burseae
i. Subscapular
1. Opens into the joint capsule
ii. Subdeltoid
iii. Subacromial
1. Located near the joint cavity
2. Separated from the cavity by the joint capsule
iv. Subcoracoid 2
HUMERUS
Definition
· Humerus is the bone that runs from the shoulder to the elbow
Movement
· Ball and socket joint allows rotational for movement
Function
· Attaches the shoulder to the forearm
· Attachment site for muscles
Articulations
· Head of the humerus articulates with the glenoid cavity of the scapula
proximally
o This forms the ball and socket joint of the shoulder
· Capitulum articulates with the ulna distally
o This forms the hinge joint of the elbow 1
Definition
· Humerus is the bone that runs from the shoulder to the elbow
Movement
· Ball and socket joint allows rotational for movement
Function
· Attaches the shoulder to the forearm
· Attachment site for muscles
Articulations
· Head of the humerus articulates with the glenoid cavity of the scapula
proximally
o This forms the ball and socket joint of the shoulder
· Capitulum articulates with the ulna distally
o This forms the hinge joint of the elbow 1
SCAPULA
Definition
· The shoulder blade
· Flat, triangular bone
· One of two bones that form the
shoulder girdle
Movement
· Elevation
· Depression
· Abduction
· Adduction
· Lateral (upward) rotation
· Medial (downward) rotation
· Posterior tipping
· Anterior tipping
Function
· Connects the clavicle to the
humerus
· Attachment site for some muscles of the shoulder
Articulations
· Articulates with the clavicle laterally
o Forms the acromioclavicular joint
· Articulates with the head of the humerus at the glenoid cavity
o Forms the ball and socket joint of the shoulder
Scapular Landmarks
1. Acromion
a. Is felt at the tip of the shoulder
b. Forms an attachment for the clavicle
c. Is an attachment site for some shoulder muscles
2. Scapular Spine
a. Extends from the acromion process across the posterior surface of the scapula
b. Divides the scapula into the supraspinatous fossa and the infraspinatous fossa
c. The inferior section of the scapula is the subscapular fossa
3. Coracoid Process
a. Provides attachments for some shoulder and arm muscles
4. Glenoid Cavity
a. Located in the superior lateral portion of the bone
b. Articulates with the head of the humerus 1
Definition
· The shoulder blade
· Flat, triangular bone
· One of two bones that form the
shoulder girdle
Movement
· Elevation
· Depression
· Abduction
· Adduction
· Lateral (upward) rotation
· Medial (downward) rotation
· Posterior tipping
· Anterior tipping
Function
· Connects the clavicle to the
humerus
· Attachment site for some muscles of the shoulder
Articulations
· Articulates with the clavicle laterally
o Forms the acromioclavicular joint
· Articulates with the head of the humerus at the glenoid cavity
o Forms the ball and socket joint of the shoulder
Scapular Landmarks
1. Acromion
a. Is felt at the tip of the shoulder
b. Forms an attachment for the clavicle
c. Is an attachment site for some shoulder muscles
2. Scapular Spine
a. Extends from the acromion process across the posterior surface of the scapula
b. Divides the scapula into the supraspinatous fossa and the infraspinatous fossa
c. The inferior section of the scapula is the subscapular fossa
3. Coracoid Process
a. Provides attachments for some shoulder and arm muscles
4. Glenoid Cavity
a. Located in the superior lateral portion of the bone
b. Articulates with the head of the humerus 1
CLAVICLE
Definition
· A bone that runs between the sternum and the
acromion of the scapula
· A long bone with a slight s-curve.
Movement
· Holds the upper limb away from the body,
therefore facilitating limb mobility
Articulations
· Lateral end articulates with the acromion
process
o Forms the acromioclavicular joint
· Medial end articulates with the sternum
o Forms the sternoclavicular joint
Function
· Clavicle connects the shoulder girdle to the
axial skeleton 1
Definition
· A bone that runs between the sternum and the
acromion of the scapula
· A long bone with a slight s-curve.
Movement
· Holds the upper limb away from the body,
therefore facilitating limb mobility
Articulations
· Lateral end articulates with the acromion
process
o Forms the acromioclavicular joint
· Medial end articulates with the sternum
o Forms the sternoclavicular joint
Function
· Clavicle connects the shoulder girdle to the
axial skeleton 1
BICEPS TENDON
Definition
· Biceps muscle is located on the anterior part of the upper arm
· Has a long and short head
· Proximal biceps tendon attaches to the shoulder joint in two places
Origin
· Long head:
o Supraglenoid tubercle of the scapula
· Short head:
o Coracoid process of scapula
Insertion
· Radial tuberosity and bicipial aponeurosis of forearm
Movement
· Outward rotation of forearm
· Flexion
Function
· Attaches the biceps muscle to the bones in order to move the forearm 2
Definition
· Biceps muscle is located on the anterior part of the upper arm
· Has a long and short head
· Proximal biceps tendon attaches to the shoulder joint in two places
Origin
· Long head:
o Supraglenoid tubercle of the scapula
· Short head:
o Coracoid process of scapula
Insertion
· Radial tuberosity and bicipial aponeurosis of forearm
Movement
· Outward rotation of forearm
· Flexion
Function
· Attaches the biceps muscle to the bones in order to move the forearm 2
BURSA
Definition
· A sac between two moving surfaces
· Contains lubricating fluid 3
Articulations
· Bursa lies between:
o Subscapularis tendon and capsule
o Deltoid and capsule
o Infraspinatous tendon and the capsule
o Summit of the acromion
o Coracoid process and capsule
o Beneath coracobrachialis
o Teres minor and triceps brachii (long head) 4
Function
· Reduce the friction between two parts of the body that are rubbing together 3
Definition
· A sac between two moving surfaces
· Contains lubricating fluid 3
Articulations
· Bursa lies between:
o Subscapularis tendon and capsule
o Deltoid and capsule
o Infraspinatous tendon and the capsule
o Summit of the acromion
o Coracoid process and capsule
o Beneath coracobrachialis
o Teres minor and triceps brachii (long head) 4
Function
· Reduce the friction between two parts of the body that are rubbing together 3
JOINT CAPSULE
Definition
· Surrounds the ball and socket joint
· Separates the joint from the rest of the body
· Contains joint fluid (synovial fluid)
· Contains several ligaments 5
· It is a piece of tissue surrounding a synovial joint
· Inner layer: synovial membrane
· Outer layer: fibrous tissue
Movements
· Multi-axial movement
Function
· Has lubrication to help movement
· Holds synovial fluid
· Envelopes the shoulder joint 6
Definition
· Surrounds the ball and socket joint
· Separates the joint from the rest of the body
· Contains joint fluid (synovial fluid)
· Contains several ligaments 5
· It is a piece of tissue surrounding a synovial joint
· Inner layer: synovial membrane
· Outer layer: fibrous tissue
Movements
· Multi-axial movement
Function
· Has lubrication to help movement
· Holds synovial fluid
· Envelopes the shoulder joint 6
Shoulder Muscles
Links:
References
1. Seeley, R., VanPutte, C., Regan, J., Russo, A. (2011). Seeleys anatomy and physiology: Ninth edition. New York, NY: McGraw Hill. 2. Fitness and Exercise. (n.a.)(n.d.). Web MD. Retrieved from http://www.webmd.com/fitness-exercise/picture-of-the-biceps
3. Shoulder Bursae. (n.a.)(n.d.). Shoulderdoc.co.uk. Retrieved from http://www.shoulderdoc.co.uk/article.asp?article=1182
4. Humeral Articulation or Shoulder-Joint. (n.a.)(n.d.). Yahoo! Education. Retireved from http://education.yahoo.com/reference/gray/subjects/subject/83
5. Cluett, J. (2010). Shoulder Anatomy. About.com Orthopedics. Retrieved from http://orthopedics.about.com/od/anatomy/p/shoulder.htm
6. What is a Joint Capsule? (n.a.)(n.d.). Wise Geek. Retrieved from http://www.wisegeek.org/what-is-a-joint-capsule.htm
1. Seeley, R., VanPutte, C., Regan, J., Russo, A. (2011). Seeleys anatomy and physiology: Ninth edition. New York, NY: McGraw Hill. 2. Fitness and Exercise. (n.a.)(n.d.). Web MD. Retrieved from http://www.webmd.com/fitness-exercise/picture-of-the-biceps
3. Shoulder Bursae. (n.a.)(n.d.). Shoulderdoc.co.uk. Retrieved from http://www.shoulderdoc.co.uk/article.asp?article=1182
4. Humeral Articulation or Shoulder-Joint. (n.a.)(n.d.). Yahoo! Education. Retireved from http://education.yahoo.com/reference/gray/subjects/subject/83
5. Cluett, J. (2010). Shoulder Anatomy. About.com Orthopedics. Retrieved from http://orthopedics.about.com/od/anatomy/p/shoulder.htm
6. What is a Joint Capsule? (n.a.)(n.d.). Wise Geek. Retrieved from http://www.wisegeek.org/what-is-a-joint-capsule.htm