Fingers Joints Flexion and Extension Quiz

Fingers Joints Flexion and Extension

• Objectives: Students will learn about the origin, insertion, nerve supply, and action of the primary muscles involved in metacarpo-phalangeal, proximal interphalangeal, and distal interphalangeal joint flexion and extension. They will also identify the range of motion and test procedures for each. Additionally, they will understand the effects of muscle weakness.

Metacarpo-phalangeal Joints Flexion Motion

• Primary Muscles: Flexor digitorum superficialis and Flexor digitorum profundus
• Range of Motion: 0° to 90° flexion, accompanied by interphalangeal joint extension.
• Anatomy of Flexor digitorum superficialis: Originates from the medial epicondyle of the humerus, medial ligament of the elbow, and medial border of the coronoid process and fibrous arch. Insertion is on the sides of the middle phalanges of the medial four fingers. Innervated by the median nerve. Primary action is flexing proximal interphalangeal joints and aiding in wrist flexion
• Anatomy of Flexor digitorum profundus: Originates from the medial olecranon and anterior/medial surface of the ulna. Insertion is on the distal phalanges of the medial four fingers. Innervations vary across the muscle; median for some parts, ulnar for others. The primary action is distal interphalangeal joint flexion.
• Effects of Weakness: Weakness in these muscles can lead to claw hand deformity.

Proximal Interphalangeal Joints Flexion Motion

• Primary Muscles: Flexor digitorum superficialis
• Accessory Muscle: Flexor digitorum profundus
• Range of Motion: 0° to 120°

Distal Interphalangeal Joints Flexion Motion

• Primary Muscle: Flexor digitorum profundus
• Range of Motion: 0° to 80°

Metacarpo-phalangeal Joints Extension Motion

• Primary Muscles: Extensor digitorum communis, Extensor indicis proprius, Extensor digiti minimi
• Range of Motion: 0° to 20°-30°
• Anatomy of Extensor digitorum communis: Originates from the lateral epicondyle of the humerus, via a common tendon. Insertion in the extensor expansion of the middle and distal phalanges of digits 2-5. Innervated by the radial nerve. Its action extends the metacarpophalangeal joints, proximal and distal interphalangeal joints, and has a supporting action on wrist and elbow extension.
• Anatomy of Extensor indicis proprius: Originates from the posterior distal third of the ulna and interosseous membrane, projects into the dorsal aponeurosis of the index finger. Innervated by radial nerve. Action is extending the index finger and aiding in wrist extension
• Anatomy of Extensor digiti minimi: Originates from the common extensor origin on the anterior aspect of the humerus' lateral epicondyle. Insertion: Extensor expansion of the little finger. Innervation: Radial Nerve. Action extends all joints of the little finger.

This quiz covers the anatomy and physiology of finger joint flexion and extension, focusing on the metacarpo-phalangeal and interphalangeal joints. Students will explore the primary muscles involved, their range of motion, and how muscle weakness affects joint movement. Test your knowledge of muscle origins, insertions, and nerve supplies.