The Elbow Joint: Functions And Location! Quiz

The triceps are responsible for elbow extension, which is the action of straightening the arm at the elbow joint. When the triceps contract, they pull on the forearm bone (ulna), causing it to extend and the angle between the upper arm (humerus) and the forearm to increase. This movement is the opposite of elbow flexion, which is the action of bending the arm at the elbow joint. Therefore, the correct answer is "Elbow Extension".

The prime movers in elbow flexion are the muscles responsible for initiating and carrying out the movement. In this case, the brachialis, biceps, and brachioradialis are the primary muscles involved in flexing the elbow joint. These muscles work together to contract and shorten, causing the forearm to move towards the upper arm. The biceps muscle is the most well-known and prominent muscle in this group, but the brachialis and brachioradialis also play important roles in elbow flexion.

The bony end landmark of the ulna that forms the prominent posterior point of the elbow is the olecranon process. This bony projection can be easily palpated and is important for the attachment of muscles and ligaments involved in elbow movement. The olecranon process acts as a lever during extension of the forearm and provides stability to the elbow joint. The other options mentioned, such as the olecranon fossa, coronoid process, and radial head, are not the correct answer as they are different anatomical structures within the elbow joint.

The weakness of the biceps brachii muscle suggests trauma to the musculocutaneous nerve. The musculocutaneous nerve innervates the biceps brachii muscle, which is responsible for flexing the elbow joint. If there is weakness in this muscle, it indicates damage or trauma to the musculocutaneous nerve, which supplies the motor function to the biceps brachii muscle.

The muscles that would act on the forearm to neutralize forearm supination are the pronator teres and pronator quadratus. These muscles work together to rotate the forearm inward, counteracting the outward rotation of supination. The triceps and anconeus muscles are responsible for extending the forearm, while the brachialis and brachioradialis muscles are involved in flexion of the forearm. Therefore, the correct answer is pronator teres and pronator quadratus.

The muscle that originates on the humeral lateral condyle and inserts on the radial styloid process is the brachioradialis. This muscle is located in the forearm and is responsible for flexing the forearm at the elbow joint. It is innervated by the radial nerve and plays a role in stabilizing the wrist during certain movements.

The bony landmark located at the posterior lateral side of the radius at the distal end is called the styloid process.

Elbow extension occurs in the sagittal plane through a frontal axis. The sagittal plane divides the body into left and right halves, while the frontal axis runs from side to side. Elbow extension refers to straightening or extending the elbow joint, which involves the movement of the forearm away from the upper arm in the sagittal plane around the frontal axis.

When a patient performs a chair push up to strengthen the elbow triceps, it is considered a closed chain activity. In a closed chain activity, the distal segment of the body (in this case, the hands) is fixed or in contact with a stable surface (the chair), while the proximal segment (the upper body) moves. In this exercise, the hands are fixed on the chair while the upper body moves up and down, making it a closed chain activity.

The interosseous membrane is a broad, flat membrane located at the posterior lateral side of the radius at its distal end. It serves as a connection between the radius and ulna bones in the forearm, providing stability and support to the joint. The interosseous membrane helps to distribute forces between the two bones during movement and also allows for slight rotation of the radius around the ulna.

Point tenderness at the common flexor origin at the elbow is a characteristic symptom of medial epicondylitis, also known as golfer's elbow. This condition is caused by inflammation or irritation of the tendons that attach to the medial epicondyle, resulting in pain and tenderness on the inner side of the elbow. Lateral epicondylitis, also known as tennis elbow, would cause pain on the outer side of the elbow. Tendonitis of the biceps tendon would cause pain in the front of the elbow, and Volkmann's ischemic contracture is a condition characterized by muscle and nerve damage due to decreased blood flow, which would not typically present with point tenderness at the common flexor origin.

The muscle that originates on the lateral epicondyle of the humerus and inserts on the anterior surface of the proximal radius is the Supinator.

The Brachialis muscle originates on the distal half of the humerus (anterior surface) and inserts on the coronoid process and the ulnar tuberosity of the ulna.

The medial collateral ligament spans the elbow longitudinally on the little finger side of the elbow. It is responsible for providing stability to the inner side of the elbow joint and preventing excessive side-to-side movement.

The weakness of the pronator teres muscle could indicate trauma to the Median Nerve. The pronator teres muscle is innervated by the Median Nerve, which means that damage or trauma to this nerve can result in weakness or paralysis of the muscle. The other nerves listed (Musculocutaneous, Ulnar, and Radial) do not innervate the pronator teres muscle, so damage to these nerves would not cause weakness in this specific muscle.

The carrying angle at the elbow exists because the medial structures extend farther distally than the lateral structures. This anatomical difference causes the forearm to naturally angle away from the body when the arm is fully extended.

Lateral epicondylitis, also known as tennis elbow, is a common elbow pathology caused by repetitive wrist extension activities. It is characterized by inflammation and pain on the outer side of the elbow. This condition is commonly seen in individuals who engage in activities such as tennis, painting, or typing, which involve repetitive use of the wrist and forearm muscles. Medial epicondylitis, on the other hand, refers to inflammation and pain on the inner side of the elbow, and is caused by repetitive wrist flexion activities. Tendonitis of the biceps tendon and Volkmann's ischemic contracture are unrelated conditions.

The correct answer is "There is more supination than pronation." This means that the forearm has a greater range of motion in the supination direction compared to pronation.

The brachialis muscle is the most effective (strongest) elbow flexor with the forearm in the neutral position. This is because the brachialis muscle is located deep to the biceps brachii and attaches to the ulna, which allows it to generate a greater force for flexion. The biceps brachii is also a strong elbow flexor, but it is more effective when the forearm is supinated (turned palm up). The brachioradialis and coracobrachialis muscles are also elbow flexors, but they are not as strong as the brachialis.

Weakness in the Triceps brachii muscle may indicate trauma to the radial nerve. The radial nerve innervates the Triceps brachii, responsible for extending the elbow joint. Damage to this nerve can lead to weakness or paralysis of the Triceps brachii muscle, affecting elbow extension and overall arm function.

When the shoulder is flexed and the elbow is flexed, the biceps brachii muscle is in a shortened position. This means that the muscle is already contracted, and further flexion at both joints would not allow the muscle to generate a strong contraction. This is known as active insufficiency, where the muscle is unable to produce an optimal force due to being in a shortened position at both joints. Therefore, shoulder flexion and elbow flexion would potentially make the biceps brachii muscle actively insufficient.