The Uses of Finger Joints

Hand function is essential to activities of daily living, work duties and leisure activities.There are two joints in the thumb: the metacarpophalangeal joint and the interphalangeal joint. Three joints are also found in each of the remaining fingers: the metacarpophalangeal joint, proximal interphalangeal joint and the distal interphalangeal joint. Finger joints are powered by muscles that connect to the bones via tendons.

Thumb Joint Function

• The joints of the thumb provide mobility that is important to the function of the entire hand and arm.The thumb provides the ability to pinch in multiple positions. Tip pinch describes the ability to grasp an object between the tip of the thumb and another fingertip, most commonly the index finger. This allows a person to write, get dressed, pick up objects and use the hand as a stabilizer for the opposite hand, like holding paper while cutting with scissors. The thumb is also capable of lateral pinching, which provides the ability to hold an object between the thumb and side of the hand. This pinch is required to hold and turn a key and is also referred to as the key pinch.

Metacarpophalangeal Joints

• The metacarpophalangeal (MCP) joints, commonly referred to as the large knuckles, are positioned between the hand and the bottom of each finger. These joints bend and straighten, which allows a person to hold a book by the binding, drink from a coffee cup and carry a dinner plate. The MCP joints work together with other finger joints to make a tight fist.

Interphalangeal Joints

• Each finger is compromised of a proximal (PIP) and distal interphalangeal (DIP) joint. These joints allow the fingers to bend and straighten. The interphalangeal joints are used to grasp and hold onto an object such as the handle of a suitcase.In addition, intricate hand movements like playing the piano, sculpting pottery, writing and typing require the MCP, PIP and DIP joints to work together.

Finger Joint Injury

• Injury to any of the thumb or finger joints can cause significant disability, and specialized medical attention may be required. Due to the complex anatomy of the hand, orthopedic surgeons often obtain additional training to develop skills required for hand surgery. In addition, some physical and occupational therapists choose to specialize in the treatment of upper extremity injuries by becoming certified hand therapists (CHT).