Shoulder Joint, Posterior Arm and Forearm Flashcards
Proximal and distal attachments of the deltoid? Actions?
Proximal: lateral third of Clavicle and inferior aspect of scapular spine
Distal: Deltoid Tuberosity of humerus
Action: anterior part flexes, medially rotates arm. middle part abducts the arm and posterior part extends and laterally rotates the arm.
Innervation of the deltoid?
Axillary nerve
Describe sensory innervation to the posterior aspect of the arm?
Medially: Anterior rami of spinal nerves C8, T1 & T2. This is therefore a common site for cardiac referred pain, especially to the left upper limb, via the intercostobrachial nerve and medial and posterior cutaneous nerves of arm and medial cutaneous nerve of forearm.
Laterally: Anterior rami of spinal nerves C5 & C6 via the axillary nerve.
What is the only muscle of the posterior compartment of the arm?
Triceps brachii (3 heads)
Proximal and distal attachments of the triceps brachii muscle? Action?
Proximal Attachments: Infraglenoid tubercle of the scapula (long head), humerus superior to the radial groove (lateral head), humerus inferior to the radial groove (medial head)
Distal Attachment: All three heads combine to form the triceps tendon, which attaches to the olecranon process of the ulna.
Action: Weak extension of the arm at the shoulder joint, and extension of the forearm at the elbow joint.
Innervation of the triceps brachii?
Radial nerve- C6, 7 and 8
The deltoid and teres minor are supplied by?
Axillary nerve
Describe where the axillary nerve is found?
Between teres minor superiorly, teres major inferiorly, the long head of triceps medially and the humerus laterally.
What area of skin is supplied by the axillary nerve? How is this clinically relevant?
The area of skin innervated by the axillary nerve is called the “badge patch” (lateral aspect of arm).Patients who have sustained an inferior dislocation of the shoulder joint should undergo specific assessment of sensation (i.e. checking for anaesthesia) in the region of the badge patch to test the function of the axillary nerve.
The radial nerve passes from the axilla into the ____1_____ compartment of the arm where it is found in the _____2______ of the humerus. After supplying ____3_____ the radial nerve leaves the posterior compartment of the arm to enter the____4____ aspect of the cubital fossa before returning to the posterior aspect of the limb in the _______5_______
1) posterior
2) radial groove
3) triceps brachii
4) lateral
5) posterior compartment of the forearm.
Superficial layer of posterior forearm muscles? (7)
Brachioradialis, Extensor Carpi Radialis Longus, Extensor Carpi Radialis Brevis, Anconeus, Extensor Digitorium, Extensor Carpi Ulnaris, Extensor Digiti Minimi
Deep layer of posterior forearm muscles?
Suppinator, Abductor Pollicis Longus, Extensor Pollicis Longus, Extensor Pollicis Brevis, Extensor Indicis.
Innervation of the posterior compartment of the forearm?
All the radial nerve
The radial nerve divides into a superficial and a deep branch just anterior to the _____1______
The deep branch passes into the ______2_______of the forearm by winding around the neck of the radius and passing through supinator muscle, which it supplies. After passing through ____3_____ the deep branch is renamed the _______4_______, which supplies the muscles of the posterior compartment of the forearm.
1) lateral epicondyle
2) posterior compartment of the forearm
3) supinator
4) posterior interosseous nerve
Where do all the superficial muscles of the posterior forearm attach to?
These muscles attach proximally to the common extensor tendon on the lateral epicondyle of the humerus.
