Upper Limb Flashcards
What does the appendicular skeleton include?
Upper limb
- Pectoral Girdle (Clavicle (collarbone) + scapula (shoulder blade))
- Bones of the arms/hands
Lower limb
- Pelvic Girdle (Pelvis: Ilium, Ischium, Pubis)
- Bones of the legs/feet
What does the upper limb include?
- Shoulder (Axilla, scapula & pectoral/breast regions)
- Arm (shoulder – elbow/cubitis)
- Forearm (elbow – wrist)
- Hand (wrist, hand & digits)
The upper limb is a ________ limb which means it is specialised for grip & grasping objects.
Weight bearing not important and so bones are ______ and less ______.
The upper limb & pectoral girdle are ______ attached to the body, making it highly ______ but with poor _______.
The upper limb is a PREHENSILE limb which means it is specialised for grip & grasping objects.
Weight bearing not important and so bones are LIGHTER and less ROBUST
The upper limb & pectoral girdle are LOOSELY attached to the body, making it highly MOBILE but with poor STABILITY.
What movements occur at the shoulder?
- flexion/extension
- abduction/adduction
- internal/external rotation
What movements occur at the elbow?
- flexion/extension
* pronation/supination
What movements occur at the wrist?
- flexion/extension
* abduction/adduction
The pectoral girdle is made up of the Scapula and Clavicle. There are 2 main joints: the sternoclavicular joint and acromioclavicular joint. Describe each.
Sternoclavicular joint • the only upper limb joint that directly articulates with the trunk • manubrium & medial clavicle • ball and socket joint • Strengthened by ligaments
Acromioclavicular joint
• lateral clavicle & acromion of scapula
• Gliding synovial joint
Describe the clavicle
The clavicle, or collar bone, is the first bone to ossify in the foetus. It is highly visible/palpable.
The manubrium of the sternum joins to the acromion of †he scapula.
It has slight sigmoid curves, which is space for vessels/nerves that go into the axilla.
The clavicle acts as strut so limb swings clear of trunk
There are strong ligaments of Sternoclavicular joint, and so the clavicle is rarely dislocated but often fractured.
Describe the scapula
The scapula is a large flat triangular bone. It overlaps ribs 2-7 on posterior. The scapula is mostly held in place by muscles.
Spine = sharp ridge on posterior surface
Acromion process = lateral, high point of shoulder, articulates with clavicle & shoulder muscles
Coracoid process = lateral & anterior, muscles attach
Glenoid cavity – Lateral, inferior to acromion, articulates with humerus
What does the humerus articulate with at the elbow and shoulder?
At Shoulder: Head articulates with glenoid cavity
At Elbow: Articulates with 2 forearm bones Laterally - radius at humerus, Medially - ulna at humerus
The shoulder joint is called the Glenohumeral joint. It is made up of the head of the humerus + glenoid cavity. It is a ______, multiaxial ball & socket joint with extensive free range of movement- more than any other joint. This is because the _____ head is 4 times too big for _____. Because of this it also has poor _______- it is the most frequently dislocated joint. It has a thin loose capsule which adds some stability. It has 4 _______ which provide more stability by ______ the capsule, and most stability comes from _______.
The shoulder joint is called the GLENOHUMERAL joint. It is made up of the head of the humerus + glenoid cavity. It is a SYNOVIAL, multiaxial ball & socket joint with extensive free range of movement- more than any other joint. This is because the HUMERUS head is 4 times too big for FOSSA. Because of this it also has poor STABILITY- it is the most frequently dislocated joint. It has a thin loose capsule which adds some stability. It has 4 LIGAMENTS which provide more stability by THICKENING the capsule, and most stability comes from MUSCLES.
How do the 2 sets of muscles attaching the humerus to scapula each effect the shoulder?
- Attach close to shoulder: Smaller mechanical effect on shoulder, stabilise joint
- Attach further away: Considerable mechanical effect on shoulder, Wide range movements at shoulder joint due to instability
Describe shoulder dislocation
Most frequently dislocated joint e.g. fall on outstretched hand: arm abducted, humeral head pushes against weakest part of capsule (inferior and anterior), tears ligaments and articular capsules
Describe rotator cuff injuries
Common injury during repetitive use limb above the horizontal – e.g. swimming, throwing, racket sports, frozen shoulder - Irritation and inflammation of tendons, shoulder stiffness
Describe axillary nerve damage
May be injured with dislocations with head of humerus, causes paralysis of deltoid and loss of sensation in small area of skin over deltoid
