Arm And Elbow Lecture Notes PDF

©  The Arm and Elbow Dr. Sean McWatt, PhD [email protected] © Danny Quirk Artwork Learning Outcomes By the end of this lesson, you will be able to… Identify and describe the bones, joints, and ligaments re...

©  The Arm and Elbow Dr. Sean McWatt, PhD [email protected] © Danny Quirk Artwork Learning Outcomes By the end of this lesson, you will be able to… Identify and describe the bones, joints, and ligaments related to the arm and elbow, and explain the basic movements that occur at the elbow Identify the muscles of the arm, and describe their innervations and functions Describe the borders and contents of the cubital fossa Predict functional implications of musculoskeletal injuries to the arm region Regions of the Upper Limb Deltoid region Shoulder Scapular region Arm Anterior and posterior compartments Axillary region Armpit Cubital fossa Elbow We will run through the anatomy of the upper limb according to these regions, from proximal to distal. Dorsal Palmar Back Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Posterior view © 2010, Icon Learning Systems, LLC. A subsidiary of MediMedia, USA, Inc. All right reserved Bones of the Upper Limb Clavicle Sternoclavicular joint Shoulder joint The humerus articulates with the Scapula scapula proximally to form the shoulder joint, distinguishing the shoulder from the arm. Humerus The humerus articulates with the Elbow joint radius and ulna distally to form the elbow joint, distinguishing the arm Radius from the forearm. Ulna The elbow joint (synovial) acts mostly as a hinge joint, but also as a pivot joint during pronation and supination of the forearm, wherein the radius rotates across the ulna. Anterior view Posterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Bones, Joints, and Ligaments  Anterior Posterior Osteology Trochlea = ‘Pulley’ view view Shaft of humerus Head of the humerus Intertubercular Anatomical neck groove Surgical neck Medial Olecranon http://tiny.cc/ebptdz epicondyle fossa Trochlea Capitulum Lateral The distal humerus, epicondyle radius, and ulna have Head of Coronoid several important process the radius bony landmarks for Olecranon joint articulations and process muscle attachments. Anterior view Radial/ulnar tuberosities Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  Elbow Joints Cubital joint Olecranon and coronoid processes Limit hyperflexion and hyperextension Lateral view Humeroradial Humeroulnar Medial view joint joint Radioulnar Olecranon joint fossa Proximal Olecranon process The olecranon process of the ulna locks within the olecranon fossa of the humerus to prevent hyper- extension at the elbow. Posterior view Anterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Radiography What’s wrong with Cubital joint this picture? dislocation! Humeroulnar Humeroradial joint joint Cubital joint Proximal radioulnar joint Anterior view Anterior view Lateral view Upper Limb Radiology Tutorial - https://www.mededportal.org/doi/10.15766/mep_2374-8265.10167 Elbow Ligaments Tommy John surgery http://tiny.cc/48dudz Annular http://tiny.cc/0aeudz ligament of radius Joint capsule Ulnar collateral Radial ligament collateral ligament The radial collateral ligament prevents abduction at the elbow, while the ulnar collateral ligament prevents adduction at the elbow. Both Anterior view support the cubital joint. Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2013 by Lippincott Williams and Wilkins Radial Head Subluxation Annular ligament Proximal of radius radioulnar joint Superior view Pinched annular ligament The annular ligament of the radius anchors the head of the radius against the ulna to Lateral view Anterior view (pronated) support the radioulnar joint. Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Moore et al., Clinically Oriented Anatomy. All Rights Reserved. ©2012 by Lippincott Williams & Wilkins. Muscles of the Arm NOTE! I have given you very detailed information about the muscles’ attachments. These are there for your reference and explanation purposes, but you do not need memorize them. You will find a muscle chart at the end of the lecture with the detail that you are expected to know. Compartments of the Arm Intermuscular Posterior septum Deep fascia separating compartment the compartments Muscles of the extensor compartment that are innervated by the radial n. Anterior compartment Lateral Muscles of the flexor compartment that are innervated by the musculocutaneous n. Remember, muscles are grouped into compartments by thick layers of fascia. Transverse view (inferior) Inflammation within these compartments can cause pain and functional deficits, known as Fascia Containing arm compartment syndrome. muscles Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  Posterior Compartment Muscles Triceps brachii m. Common insertion: Olecranon process of the ulna Long head Origin: Infraglenoid Innervation: tubercle of scapula Radial n. (C5–T1) Lateral head Running through the radial groove Origin: The triceps brachii m. is the Shaft of the humerus above the radial groove only muscle in the posterior compartment of the arm… Medial head Origin: …all three heads contribute to Shaft of the humerus extension at the elbow. The long below the radial groove head also contributes to adduction and some extension at the shoulder. Posterior views Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Transverse view Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2013 by Lippincott Williams and Wilkins Radial Nerve Radial n. The radial nerve runs The radial nerve innervates with the deep brachial a. posterior to the humerus all muscles in the posterior through the radial groove. compartments of the Deep to the lateral head of triceps brachii arm and forearm. Anterior view (pronated) Posterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme  Anterior Compartment Muscles Long head Origin: Biceps brachii m. Supraglenoid tubercle of scapula Radial tuberosity Innervation: Musculocutaneous n. (C5–C7) Supination Biceps brachii m. Common insertion: The biceps brachii m. Radial tuberosity and Short head crosses both the shoulder bicipital aponeurosis Origin: and elbow joints. Coracoid process of scapula Its main action is supination of the forearm, but it also contributes to flexion at the shoulder and elbow joints. Bicipital aponeurosis Transverse view Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Anterior view Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2013 by Lippincott Williams and Wilkins Popeye Sign Torn tendon of the long head of biceps brachii m. If a tendon tears, the biceps brachii m. will cluster into a ball Reverse when flexed, giving Popeye sign Torn biceps the appearance of brachii tendon Popeye flexing. (distal) Anterior views https://tonygentilcore.com/wp-content/uploads/2018/01/popeye.png https://image.slidesharecdn.com/distalbicepstendonrupture-171016165833/95/distal-biceps-tendon-rupture-5-638.jpg?cb=1527975412 Anterior Compartment Muscles The coracobrachialis m. contributes to flexion Coracobrachialis m. and adduction of the arm at the shoulder joint. Origin: Coracoid process of scapula Insertion: Shaft of the humerus Innervation: Musculocutaneous n. (C5–C7) The brachialis m. is the most powerful flexor Brachialis m. Origin: of the forearm at the Shaft of the humerus elbow, regardless of Insertion: the position of the Ulnar tuberosity forearm (i.e., pronated or supinated) Ulnar tuberosity Anterior view Transverse view Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2013 by Lippincott Williams and Wilkins Musculocutaneous Nerve The musculocutaneous n. pierces the coracobrachialis m. and proceeds to innervate the entire anterior compartment of the arm. It terminates as the lateral cutaneous n. of the forearm, innervating the skin of the lateral aspect of the forearm (as its name suggests). Musculocutaneous n. Lateral cutaneous n. of the forearm Anterior view Gilroy, Anatomy: An Essential Textbook, Copyright © 2013 by Thieme Cutaneous Nerve Map Medial cutaneous nn. of the arm and forearm From medial cord of the brachial plexus In the arm and forearm, the axillary n. provides cutaneous innervation to the Axillary n. lateral shoulder region, the radial n. is responsible for the posterior arm and forearm, and the musculocutaneous n. provides cutaneous innervation to the lateral forearm. Radial n. Musculocutaneous n. Anterior view Posterior view Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Cubital Fossa  Cubital Fossa The cubital fossa is the second neurovascular Axilla funnel of the upper limb. Cubital fossa Carpal tunnel It has five borders (medial, lateral, superior, anterior, and posterior) and contains several major structures of note. Anterior view Anterior view Drake, Gray’s Anatomy for Students, 2nd Ed., Copyright © 2009 by Churchill Livingstone Cubital Fossa Radial n. Bifurcating into superficial and Posterior deep branches border (floor) Supinator m. Brachialis m. Superior border Imaginary line between the medial and lateral Median n. epicondyles of the humerus Lateral border T A T A N N Tendon of Brachioradialis m. e r e n t r biceps brachii m. Median cubital v. d e v Brachial a. Cut Brachial a. o r e Splitting into ulnar Median n. and radial aa. n y Anterior view (right) Medial border Anterior Pronator teres m. border (roof) Within the cubital fossa, the radial n. bifurcates into deep Bicipital and superficial branches, the brachial a. bifurcates into aponeurosis Anterior view (right) ulnar and radial branches, and the median n. gives off many branches to supply muscles of the anterior forearm. Agur and Dalley, Grant’s Atlas of Anatomy, 13th Ed. Copyright © 2013 by Lippincott Williams and Wilkins Simplified Muscle Chart Attachments Muscle Group Muscle Origin Insertion Main action(s) Innervation Supination (elbow), flexion (elbow and Biceps brachii Radius Scapula shoulder) Anterior compartment Musculocutaneous n. of the arm Coracobrachialis Humerus Flexion (shoulder), adduction (shoulder) Brachialis Humerus Ulna Flexion (elbow) Posterior compartment Scapula, Triceps brachii Ulna Extension (elbow), adduction (shoulder) Radial n. of the arm humerus Learning Outcomes By now, you should better understand how to… Identify and describe the bones, joints, and ligaments related to the arm and elbow, and explain the basic movements that occur at the elbow Identify the muscles of the arm, and describe their innervations and functions Describe the borders and contents of the cubital fossa Predict functional implications of musculoskeletal injuries to the arm region  © [email protected]