Upper Limb Joint Mechanics and Functionality Quiz

1. What are the articicular surfaces in the HR joint?

3. The contact between the sup surface of the radial head and the capitulum decreases as the elbow flexes.

4. Increased pressure per unit of surface area is observed with given loads in positions of flexion.

When articulating surfaces in the HR joint, it is important to note that the correct contact is made between the concave articular surface of the radial head and the convexity of the capitulum on the distal humerus. This contact increases as the elbow flexes, distributing pressure evenly and reducing pressure per unit of surface area.

Explanation

When articulating surfaces in the HR joint, it is important to note that the correct contact is made between the concave articular surface of the radial head and the convexity of the capitulum on the distal humerus. This contact increases as the elbow flexes, distributing pressure evenly and reducing pressure per unit of surface area.

2. What is the Carrying Angle?

An angulation that is only visible when the arm is at a 90-degree abduction angle from the body

The carrying angle refers to the angulation formed in the frontal plane of the elbow where the humerus aligns parallel to the ulna, making it more evident in the anatomical position. This angulation is valgus in nature, meaning the distal segment moves away from the midline relative to the proximal segment, a condition known as 'Cubitus valgus'. The incorrect answers provided do not accurately describe the concept of the carrying angle.

Explanation

The carrying angle refers to the angulation formed in the frontal plane of the elbow where the humerus aligns parallel to the ulna, making it more evident in the anatomical position. This angulation is valgus in nature, meaning the distal segment moves away from the midline relative to the proximal segment, a condition known as 'Cubitus valgus'. The incorrect answers provided do not accurately describe the concept of the carrying angle.

3. What is the average carrying angle?

20-25 degrees

8-10 degrees

3-5 degrees

The average carrying angle ranges from 13-15 degrees, with it being larger in females. In men, the average is around 5-10 degrees, while in females it averages around 10-15 degrees, according to various sources.

Explanation

The average carrying angle ranges from 13-15 degrees, with it being larger in females. In men, the average is around 5-10 degrees, while in females it averages around 10-15 degrees, according to various sources.

4. What are the stabilizing structures of the elbow?

The ulnar collateral ligament provides stability primarily in rotational movements of the elbow.

The brachialis muscle helps stabilize the elbow joint during flexion and extension.

The synovial fluid within the elbow joint cavity acts as the primary stabilizing structure.

5. What are the characteristics of the HU Joint Articular Surfaces?

The correct features of the HU Joint Articular Surfaces include a single joint capsule enclosing various joints, congruent articular surfaces providing structural stability, and motion occurring in the sagittal plane. The incorrect answers provided misrepresent these characteristics by introducing incorrect descriptions of the joint capsule, articular surfaces, load effects on the cartilage, and the plane of motion.

Explanation

The correct features of the HU Joint Articular Surfaces include a single joint capsule enclosing various joints, congruent articular surfaces providing structural stability, and motion occurring in the sagittal plane. The incorrect answers provided misrepresent these characteristics by introducing incorrect descriptions of the joint capsule, articular surfaces, load effects on the cartilage, and the plane of motion.

6. What are the implications of deviations from the average carrying angle?

Bone growth

Infection

Nerve damage

Upper Limb Joint Mechanics and Functionality Quiz

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