Shoulder Girdle Module 2.1 PDF

Summary

This document details the structure and function of the shoulder girdle, including the bones, joints, and muscles involved. It also explains the various motions of the scapula and the role of the shoulder girdle in human movement.

Full Transcript

SHOULDER GIRDLE OT 505: Module 2 Professor Zilberman and Miller CLARIFICATION OF TERMS The purpose of the shoulder and the entire upper extremity is to allow the hand to be placed in various positions to accomplish daily tasks Shoulder Complex A term that includes...

SHOULDER GIRDLE OT 505: Module 2 Professor Zilberman and Miller CLARIFICATION OF TERMS The purpose of the shoulder and the entire upper extremity is to allow the hand to be placed in various positions to accomplish daily tasks Shoulder Complex A term that includes all structures involved with the motion of the shoulder Shoulder Girdle: Scapula & Clavicle Shoulder Joint: Scapula & Humerus CLARIFICATION OF TERMS Shoulder Girdle Shoulder Joint A term used to discuss the activities of ”Glenohumeral Joint” the scapula and clavicle, and to a lesser Consists of the scapula and humerus degree, the sternum BO NE S AND LANDMARKS: SC AP ULA Superior Angle: Superior, medial aspect Inferior Angle: Most inferior point and where vertebral and axillary border meet Vertebral Border: Medial border Axillary Border: Lateral border Spine: Projection on posterior surface, running from medial border laterally to the acromion process BONES AND LANDMARKS: SCAPULA Coracoid Process: Projection on anterior surface Acromion Process: Broad, flat area on superior lateral aspect Glenoid Fossa: Slightly concave surface that articulates with humerus on superior lateral side above the axillary border and below the acromion process BONES AND LANDMARKS: CLAVICLE The clavicle is an S-shaped bone that connects the upper extremity to the axial skeleton at the sternoclavicular joint Sternal End: Attaches medically to the sternum Acromial End: Attaches laterally to the scapula Body: Area between the two ends BONES AND LANDMARKS: STERNUM The sternum is a flat bone located in the midline of the anterior thorax Manubrium: The superior end, providing attachment for the clavicle and first rib Body: The middle two-thirds of the sternum, providing attachment for the remaining ribs Xiphoid Process: ”Sword-Shaped”; The inferior tip SHOULDER GIRDLE: ARTICULATION Sternoclavicular Joint Acromioclavicular Joint Scapulothoracic Articulation Glenohumeral Joint – Shoulder Joint STERNOCLAVICULAR JOINT (SC JOINT) Provides the shoulder girdle with it sonly direct attachment to the trunk This plane-shaped synovial joint allows: Elevation and Depression Protraction and Retraction Rotation The clavicle moves, while the sternum remains stationary Joint Capsule Joint Disk Serves as a shock absorber and allows motion 3 Major Ligaments Sternoclavicular Ligament Connects the clavicle to the sternum on both the anterior and posterior surfaces Costoclavicular Ligament A short, flat rhomboid-shaped ligament that connects the clavicle’s inferior surface to the superior surface of the costal cartilage of the first rib Interclavicular Ligament SC JOINT Located at the top of the manubrium, connecting the superior sternal ends of the clavicles ACROMIOCLAVICULAR JOINT (AC JOINT) The acromioclavicular joint connects the acromion process of the scapula with the lateral end of the clavicle It is a plane-shaped synovial joint The superior and inferior acromioclavicular ligaments give support to the joint by holding the acromion process to the clavicle Prevents dislocation AC JOINT Acromioclavicular Ligament: Serves to reinforce the joint capsule Coracoclavicular Ligament: Accessory Ligament (Not Directly Located At The Joint) It connects the scapula to the clavicle by attaching to the inferior surface of the clavicle’s lateral end and to the superior surface of the scapula’s coracoid process Lateral Trapezoid Portion Deeper Medial Conoid Portion Coracoacromial Ligament: Accessary Ligament (Not Directly Located At The Joint) Forms a roof over the head of the humerus and serves as a protective arch providing support to the head SCAPULAR MOTIONS SCAPULAR MOTIONS Elevation: Linear Motion Depression: Linear Motion Protraction: Linear Motion Retraction: Linear Motion Upward Rotation: Angular Motion The inferior angle of the scapula rotates up and away from the vertebral column Downward Rotation: Angular Motion The return to the resting anatomical position The scapula does not move past anatomical position toward the vertebral column SCAPULAR MOTIONS Scapular Tilt Occurs when the GH joint goes into hyperextension The superior end of the scapula tilts anteriorly The inferior end tilts posteriorly Examples: “Wind-Up” phase of a softball pitch, bowling or racing dive in swimming COMPANION MOTION OF THE SHOULDER JOINT AND SHOULDER GIRDLE SHOULDER JOINT SHOULDER GIRDLE 1. Flexion 1. Upward Rotation; Protraction 2. Extension 2. Downward Rotation; Retraction 3. Hyperextension 3. Scapular Tilt 4. Abduction 4. Upward Rotation 5. Adduction 5. Downward Rotation 6. Internal Rotation 6. Protraction 7. External Rotation 7. Retraction 8. Horizontal Abduction 8. Retraction 9. Horizontal Adduction 9. Protraction ANGLE OF PULL Determining which roll the muscle will play depends on the size of the muscle, the angle of pull, joint motions possible and location of muscle in relation to the joint axis. Angle of pull is usually a major factor to determine if prime mover (muscle has major role), assisting mover( minor role), or no role for that motion. MUSCLES OF THE SHOULDER GIRDLE These muscles provide dynamic stability to the Trapezius scapula Levator Scapula These muscles do not Rhomboids attach to the humerus and do not cause shoulder joint Serratus Anterior motion Pectoralis Minor All muscles originate on the axial skeleton and insert on the scapula or clavicle MUSCLES- TRAPEZIUS A large, superficial muscle that appears diamond-shaped Functionally, it is divided into three parts as there are three different lines of pull: Upper Trapezius Middle Trapezius Lower Trapezius MUSCLES- UPPER TRAPEZIUS Origin: Occipital bone, nuchal ligament on upper cervical spinous process Insertion: Outer third of clavicle, acromion process Action: Scapular Elevation, Upward Rotation Nerve: Spinal Accessory (Cranial Nerve XI) MUSCLES- MIDDLE TRAPEZIUS Origin: Spinous processes of C7-T3 Insertion: Scapular Spine Action: Scapular Retraction Nerve: Spinal Accessory (Cranial Nerve XI) MUSCLES- LOWER TRAPEZIUS Origin: Spinous processes of middle and lower thoracic vertebrae Insertion: Base of the scapular spine Action: Scapular Depression, Upward Rotation Nerve: Spinal Accessory (Cranial Nerve XI) MUSCLES- LEVATOR SCAPULA Origin: Transverse processes of first four cervical Insertion: Vertebral border of scapula between the superior angle and spine Action: Scapular Elevation and Downward Rotation Nerve: C3, C4 MUSCLES- RHOMBOIDS Origin: Spinous processes of C7 to T5 Insertion: Vertebral border of scapula between the spine and inferior angle Action: Scapular Retraction, Elevation & Downward Rotation Nerve: Dorsal Scapular Nerve (Roots of Brachial Plexus- C5) MUSCLES- SERRATUS ANTERIOR Origin: Lateral surface of the upper eight ribs Insertion: Vertebral border of the scapula, anterior surface Action: Scapular Protraction, Upward Rotation Nerve: Long Thoracic Nerve (Roots of Brachial Plexus- C5, C6, C7) MUSCLES- PECTORALIS MINOR Origin: Anterior surface, third through fifth ribs Insertion: Coracoid process of the scapula Action: Scapular Depression, Protraction, Downward Rotation and Tilt Nerve: Medial Pectoral Nerve (Cords of Brachial Plexus- C8, T1) * Small muscle but is houses the brachial plexus. With tightness, it can compress the brachial plexus and cause neuropathy.* MUSCLES- PECTORALIS MINOR Small muscle but is houses the brachial plexus. With tightness, it can compress the brachial plexus and cause neuropathy. PRIME MOVERS OF THE SHOULDER GIRDLE SCAPULOHUMERAL RHYTHM Movement relationship The first 30º is called the “setting phase”; the scapulothoracic is between the shoulder mostly not active and the motion girdle & shoulder joint occurs mostly GH joint First 30º of shoulder After first 30 degrees, the GH and scapulothoracic joints move motion in abduction or simultaneously flexion is pure shoulder Overall a 2: 1 ratio of GH to ST joint movement movement SCAPULOHUMERAL RHYTHM Purposes: 1. Preserves length tension relationship of the GH muscles allowing for increased force. The muscles do not shorten as much as they would without the scapula's upward rotation. 2. The scapula pulls down as the humerus elevates and this prevents impingement of the tendons in the subacromial space. DYSFUNCTIONAL SCAPULOTHORACIC MOTION Weakness Rotator Cuff Tendonitis Impingement Syndrome AC Joint Injuries Shoulder Laxity/Instability Patterns Nerve Entrapment Scapula Bursitis Subacromial Bursitis GOALS FOR DYSFUNCTIONAL SHOULDER GIRDLE 1-Pain Management 6- Activate Deltoid and GH 2-Postural Orientation depression 3-Realignment of Scapula on 7- Inhibit Upper trapezius & Chest wall other synergistic patterns 4- Develop Scapula mobility and 8- Restore Thoracic mobility Stability and proper breathing habits 5- Stretching tight structures 9- Neuromotor Training POINTS TO REMEMBER The shoulder girdle has both linear and angular motions. The inferior angle is the point of reference for scapular rotation. Certain shoulder girdle and shoulder joint motions are connected. Scapulohumeral rhythm is an example of the combined motions of these joints. Muscles pulling in different directions to accomplish the same motion are a force couple. Example: The upper trapezius muscle pulls up, the lower trapezius muscle pulls down and the lower fibers of the serratus anterior pull outwards in a horizontal direction ! Upward Rotation Concentric and eccentric are accelerating and decelerating activities. With isometric, there is no joint motion. REVIEW QUESTIONS Identify the structures that make up the shoulder girdle, the shoulder joint and the shoulder complex. Given the scapula is shaped somewhat like a triangle: What landmark is commonly used to determine the direction the scapula is rotating? What direction is the landmark moving if the scapula is rotating upwardly? Which shoulder girdle motions are mostly linear, which are mostly angular? What is the scapulohumeral rhythm? How is shoulder joint motion affected by the absence of scapulohumeral rhythm?

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