Shoulder Joint Anatomy Quiz: Rotator Cuff

Palpating for tenderness at the coracoid process of the scapula can indicate soft tissue inflammation at the origin of the coracobrachialis muscle. The coracobrachialis muscle attaches to the coracoid process and helps to flex and adduct the arm at the shoulder joint. If there is tenderness at this spot, it suggests that there may be inflammation or irritation of the coracobrachialis muscle.

Damage to the axillary nerve could result in weakness of the deltoid muscle. The axillary nerve innervates the deltoid muscle, which is responsible for abduction of the arm at the shoulder joint. If the axillary nerve is damaged, the deltoid muscle may not receive proper signals for contraction, leading to weakness or paralysis of the muscle. This can result in difficulty in raising the arm laterally away from the body.

The correct answer is All fibers of the deltoid. The deltoid muscle originates on the lateral clavicle, the top of the acromion, and the scapular spine, and inserts on the midpoint of the humerus on the lateral side. It is responsible for various movements of the shoulder joint, including abduction, flexion, and extension.

The posterior deltoid, latissimus dorsi, and teres major muscles all contribute to shoulder extension. Shoulder extension refers to the movement of the arm backward, away from the body. These muscles work together to pull the arm back, allowing for extension of the shoulder joint.

The musculocutaneous nerve innervates the coracobrachialis muscle, which is responsible for flexion and adduction of the arm at the shoulder joint. If this nerve is damaged, it can lead to weakness of the coracobrachialis muscle, affecting its function. The other nerves listed do not directly innervate the coracobrachialis muscle, so damage to them would not result in weakness of this specific muscle.

The correct answer is "Transverse plane through a vertical axis". Horizontal abduction of the shoulder refers to moving the arm away from the midline of the body in a transverse plane. This movement occurs around a vertical axis, which runs from top to bottom through the shoulder joint.

The pectoralis major, latissimus dorsi, and teres major muscles all contribute to adduction of the shoulder. Adduction refers to the movement of bringing the arm towards the midline of the body. These muscles work together to bring the arm closer to the body, allowing for movements such as hugging or crossing the arms in front of the chest.

The correct answer is the Long head of the triceps brachii. This muscle originates on the infraglenoid tubercle of the scapula and inserts on the olecranon process of the ulna.

The muscle that originates on the anterior surface of the scapula and inserts on the lesser tubercle of the humerus is the Subscapularis. This muscle is located deep within the shoulder joint and is responsible for internal rotation of the arm. It also helps stabilize the shoulder joint and assists in movements such as throwing and pushing.

The deltoid tuberosity is a bony landmark of the humerus that is located on the lateral side near the midpoint of the shaft. It serves as the attachment site for the deltoid muscle, which is responsible for shoulder abduction and flexion. The bicipital groove is located on the anterior side of the humerus and serves as a passage for the biceps tendon. The lesser tubercle is located on the anterior side of the humerus, near the anatomical neck, and serves as an attachment site for the subscapularis muscle. The humeral head is the rounded proximal end of the humerus that articulates with the glenoid cavity of the scapula to form the shoulder joint.

The latissimus dorsi muscle is responsible for shoulder hyperextension. This muscle is located in the back and connects the upper arm bone to the spine and pelvis. When the latissimus dorsi contracts, it pulls the upper arm bone backward, causing hyperextension of the shoulder joint. The other muscles listed, such as the teres major, anconeus, and infraspinatus, are not primarily involved in shoulder hyperextension.

Damage to the suprascapular nerve could result in weakness of the infraspinatus muscle. The suprascapular nerve innervates the infraspinatus muscle, which is responsible for external rotation and stabilization of the shoulder joint. If the suprascapular nerve is damaged, it can lead to weakness or paralysis of the infraspinatus muscle, affecting its ability to perform these functions effectively.

The Latissimus dorsi, subscapularis, and anterior deltoid muscles all contribute to the motion of medial rotation in the shoulder joint. Medial rotation refers to the movement of the arm or shoulder towards the midline of the body. These muscles work together to generate this motion, allowing for actions such as bringing the arm across the chest or rotating the arm towards the body.

Teres minor is the correct answer because it is one of the muscles that originates on the axillary border of the scapula and inserts on the greater tubercle of the humerus. The teres minor is a small muscle located on the lateral side of the scapula and it helps with the rotation and stabilization of the shoulder joint.

The correct answer is Pectoralis Major, clavicular portion. The pectoralis major muscle originates on the medial one-third of the clavicle and inserts on the lateral lip of the bicipital groove. It is responsible for flexion, adduction, and medial rotation of the arm at the shoulder joint.

When the shoulder is laterally rotated during abduction between 90 and 180 degrees, it allows the greater tubercle of the humerus to clear the acromion process. This movement prevents impingement or collision between the greater tubercle and the acromion, reducing the risk of injury and pain.

The most likely diagnosis for the client's shoulder pain and loss of motion due to inflammation and fibrosis of the shoulder joint is adhesive capsulitis. Adhesive capsulitis, also known as frozen shoulder, is a condition characterized by inflammation and thickening of the shoulder joint capsule, leading to pain and restricted movement. Impingement syndrome is a condition where the rotator cuff tendons become irritated and inflamed, causing pain and limited motion. Calcific tendonitis is the formation of calcium deposits in the tendons, leading to pain and inflammation. Subluxation of the long head of the biceps tendon refers to partial dislocation of the tendon, which may cause shoulder pain but is less likely to result in loss of motion.

The rotator cuff muscles primarily function to hold the humeral head against the glenoid fossa. The arthrokinematic motion of the shoulder joint that best facilitates this function is spin. Spin refers to the rotational movement of one joint surface on another, and in the case of the shoulder joint, it allows for smooth and controlled rotation of the humeral head within the glenoid fossa. This motion is important for maintaining stability and proper alignment of the shoulder joint during various arm movements.

Strong lateral capsular ligaments do not contribute to joint subluxation of the glenohumeral joint. Joint subluxation occurs when the humeral head partially dislocates from the glenoid fossa. Factors such as the weight of the upper extremity, gravity, and a shallow glenoid fossa can all contribute to joint subluxation by creating instability and allowing the humeral head to move out of its normal position. However, strong lateral capsular ligaments provide stability to the joint and help prevent subluxation.

The coracobrachialis muscle is a small muscle located in the upper arm. It originates from the coracoid process of the scapula and inserts into the medial surface of the humerus. It assists in flexion and adduction of the arm at the shoulder joint. If a person has pain in the bicipital groove, it could indicate inflammation or tendonitis of the coracobrachialis muscle. This is because the bicipital groove is the location where the long head of the biceps brachii muscle and the tendon of the coracobrachialis muscle pass through.

The teres major muscle is responsible for flexing the shoulder through its entire range. This muscle is located on the back of the upper arm and connects the scapula to the humerus bone. It works together with other muscles to allow for movements such as lifting the arm forward and upward. The teres major is a powerful muscle that assists in various actions involving the shoulder joint, including flexion.