wsa4 - LAB 4: BONES AND MUSCLES OF THE SHOULDER AND ARM...

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Unformatted text preview: LAB 4: BONES AND MUSCLES OF THE SHOULDER AND ARM BONE AND BONY LANDMARK IDENTIFICATION Bony Landmarks of the Clavicle •conoid tubercle •acromial end (distal/lateral end) •sternal end (proximal/medial end) Identify the medial and lateral ends. Which structures does either end of the clavicle articulate with? Bony Landmarks of the Scapula •spine •medial (vertebral) border •acromion (acromion process) •infraglenoid tubercle •supraspinous fossa •glenoid fossa (cavity) •infraspinous fossa •coracoid process •superior angle •subscapular fossa •inferior angle •suprascapular notch •angle of acromion •supraglenoid turbercle Tania 77-15-1 5:46 PM Comment: Medial end = sternal end: articulates with manubrium of sternum Lateral end = acromial end: articulates with acromion process of scapula •lateral (axillary) border Bony Landmarks of the Humerus (Proximal) •head •greater tubercle •anatomical neck •body (shaft) •surgical neck •lesser tubercle •deltoid tuberosity •intertubercular groove (bicipital groove) 1. What is the weakest part of the clavicle? Tania Lam 09-9-8 10:39 AM 2. Find/palpate the sternoclavicular joint. Comment: Mid ­region of clavicle, at the junction where the two curves meet 3. Note how the size of the humeral head relative to the glenoid fossa contributes to the instability of the glenohumeral joint. What structures help to stabilize this joint? 4. What is the scapulothoracic joint? 5. How does the scapula move during: depression; elevation; retraction; protraction? 6. There is a disarticulated humerus in front of you. How would you determine whether a humerus is from the left or right side? 7. Find/palpate the following landmarks: o acromion o inferior angle of the scapula o spine of the scapula o vertebral border of the scapula MUSCLES FROM THE AXIAL SKELETON TO THE CLAVICLE AND SCAPULA Origin •Trapezius Insertion Action External occipital protuberance, cervical and thoracic spinous processes Continuous from lateral 1/3 of clavicle, acromion process and spine of scapula Upper parts: elevate scapula; Middle part: retracts scapula; Lower part: depress scapula; involved in rotating and stabilizing scapula •Serratus anterior Ribs 1 ­8 or 1 ­9 Anterior surface of medial edge of scapula Protracts scapula, holds scapula against thorax •Rhomboid major T2 ­T5 spinous process Along medial edge of scapula, up to the level of the scapular spine Retracts scapula •Rhomboid minor C7 ­T1 spinous processes Medial edge of scapula at the level of the scapular spine Retracts scapula •Levator scapulae Transverse processes of C1 ­C4 Medial edge of scapula above the level of the spine Elevates scapula MUSCLES FROM THE AXIAL SKELETON TO THE HUMERUS Origin Insertion Action •Latissimus Dorsi T7 ­T12, lumbar, & sacral spinous processes, thoracolumbar fascia, iliac crest Intertubercular/bicipital groove of humerus extension, adduction, internal rotation of arm at shoulder joint •Pectoralis Major Clavicular head: Medial half of clavicle; Sternal head: sternum/costal cartilage of ribs 1 ­6 adduction, internal rotation, flexion, horizontal flexion of arm at shoulder joint MUSCLES FROM THE SHOULDER GIRDLE TO THE HUMERUS Origin •Deltoids •Teres Major Insertion Continuous from lateral Deltoid tuberosity of 1/3 of clavicle, humerus acromion process and spine of scapula **note that it is inferior to insertion of trapezius Anterior: arm flexion & med. rot. Lower 1/3 of lateral edge of scapula Arm medial rotation, adduction, extension Intertubercular groove of humerus •Infraspinatus Infraspinous fossa of scapula •Teres Minor Subscapular fossa of scapula Greater tuberosity of humerus Upper 2/3 of posterior surface of lateral edge of scapula •Subscapularis Middle: arm abduction Posterior: arm extension and lat. rot. Arm abduction (esp 1st 15 degrees), keeps humerus in glenoid fossa •Supraspinatus Supraspinous fossa of scapula Action Arm lateral rotation, keeps head of humerus in glenoid fossa Arm lateral rotation, keeps head of humerus in glenoid fossa Lesser tuberosity of humerus Arm medial rotation, keeps head of humerus in glenoid fossa 1. What muscles are responsible for each of the following actions at the shoulder? o Flexion and extension Tania Lam 09-8-9 11:36 AM Comment: answers evident from tables o Abduction and adduction o Internal and external rotation 2. Come up with some exercises that specifically train/strengthen some of the rotator cuff muscles. 3. Name 2 muscles at the elbow, 2 muscles at the shoulder, and 1 muscle of the scapulothoracic joint that are involved in the performance of a push ­up. 4. Explain why the latissumus dorsi is sometimes called the ‘swimming muscle’. 5. Contract and palpate the following muscles: o trapezius o pectoralis major o latissimus dorsi o deltoids (all 3 heads) Tania Lam 11-2-13 8:23 PM Comment: Tania Lam 09-8-9 11:36 AM Comment: triceps brachii, anconeus Tania Lam 09-8-9 11:36 AM Comment: pectoralis major, anterior deltoid Tania Lam 09-8-9 11:36 AM Comment: serratus anterior Tania Lam 09-8-9 11:36 AM Comment: front crawl: requires arm extension, internal rotation, and adduction Tania Lam 09-8-9 11:36 AM Comment: abduct arms and retract scapula to expose trapezius Tania Lam 09-8-9 11:36 AM Comment: flex, adduct, and medially rotate arm Tania Lam 09-8-9 11:36 AM Comment: place arm in external rotation and abduction to locate Tania Lam 09-8-9 11:36 AM Comment: abduct arm (preferably against resistance) ...
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This note was uploaded on 05/21/2011 for the course BHK 190 taught by Professor Janice during the Spring '11 term at UBC.

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