Question 1

Question

Describe the anatomical structure of the wrist and and hand.

Question 2

Highlight the fundamental movements of the wrist and hand.

Question 3

Discuss the joints that are found in the wrist and hand.

Question 4

Mention the last group of joints considered to be part pf the wrist are carpometacarpal joints:

Answer 1

Question 1: Anatomical Structure of the Wrist and Hand

The wrist and hand are complex anatomical structures that consist of bones, ligaments, tendons, muscles, and nerves, playing crucial roles in various functions, including grasping, manipulation, and sensation.

Wrist (Carpus)

The wrist comprises 8 carpal bones organized into two rows:

1. Proximal Row (lateral to medial):

   • Scaphoid
   • Lunate
   • Triquetrum
   • Pisiform

2. Distal Row (lateral to medial):

   • Trapezium
   • Trapezoid
   • Capitate
   • Hamate

The proximal row articulates with the radius and the articular disc of the ulna, while the distal row connects to the metacarpal bones of the hand.

Hand (Manus)

The hand consists of:

1. Metacarpals: Five long bones (I-V) that form the palm.
2. Phalanges: Bones of the fingers, each finger having three phalanges (proximal, middle, distal) except for the thumb, which has two (proximal and distal).

Soft Tissue Structures

• Ligaments: The wrist and hand are stabilized by numerous ligaments, including the collateral ligaments, dorsal ligaments, and palmar ligaments.
• Tendons: Flexor and extensor tendons facilitate movement, connecting muscles to bones.
• Muscles: Intrinsic muscles (located within the hand) and extrinsic muscles (originating in the forearm) control the movements of the hand and fingers.
• Nerves: Major nerves, including the median, ulnar, and radial nerves, serve the wrist and hand, providing motor and sensory functions.

Question 2: Fundamental Movements of the Wrist and Hand

The wrist and hand can perform a wide range of movements:

1. Wrist Movements:

   • Flexion: Bending the wrist forward (decreasing the angle between the palm and the forearm).
   • Extension: Straightening the wrist (increasing the angle between the palm and the forearm).
   • Radial Deviation (Abduction): Movement of the wrist towards the thumb side.
   • Ulnar Deviation (Adduction): Movement of the wrist towards the little finger side.
   • Circumduction: A circular movement that combines flexion, extension, abduction, and adduction.

2. Hand Movements:

   • Finger Flexion and Extension: Bending and straightening the fingers at the metacarpophalangeal and interphalangeal joints.
   • Abduction and Adduction: Moving fingers away from and towards the midline of the hand.
   • Opposition (specific to the thumb): Moving the thumb across the palm to touch the tips of the fingers.
   • Pinching and Grasping: Coordinated movements that involve multiple muscles and joints to hold objects.

Question 3: Joints Found in the Wrist and Hand

The wrist and hand contain several types of joints:

Wrist Joints

1. Radiocarpal Joint: The primary joint between the radius and the proximal row of carpal bones, allowing flexion, extension, and radial/ulnar deviation.
2. Intercarpal Joints: Joints between adjacent carpal bones, allowing for slight movements to facilitate wrist mobility.
3. Midcarpal Joint: A functional joint between the proximal and distal rows of carpal bones that contributes to wrist mobility.

Hand Joints

1. Carpometacarpal (CMC) Joints: Joints between the carpal bones and the bases of the metacarpals. The CMC joint of the thumb (saddle joint) allows for a greater range of motion compared to the other CMC joints.
2. Metacarpophalangeal (MCP) Joints: Joints between the metacarpals and proximal phalanges, allowing for flexion, extension, abduction, and adduction of the fingers.
3. Interphalangeal (IP) Joints: Joints between the phalanges. Each finger has two (proximal and distal IP), while the thumb has one IP joint, allowing flexion and extension.

Question 4: Carpometacarpal Joints

The last group of joints considered part of the wrist are the carpometacarpal (CMC) joints, which connect the carpal bones of the wrist to the metacarpal bones of the hand.

Key Features

• Location: There are five CMC joints, one for each metacarpal (I-V).
• Types of Movement:
  • The 1st CMC joint (thumb) is a saddle joint, allowing for a wide range of movements including opposition, flexion, and extension.
  • The 2nd to 5th CMC joints allow for limited movement, primarily contributing to stability and support during grasping and pinching motions.

The CMC joints play a pivotal role in the functional capacity of the hand, particularly regarding grip strength and precision of movement.