Bones of the Hand, Wrist and Forearm - Mr. Brewer

Hand Bones -The hand is very similar to the foot, not only by some of the names, but also by the overall structure. -Phalanges are still phalanges. -Instead of “Tarsals” of the foot, you have “Carpals” of the hand. -Instead of the Fibula and Tibia, we have the Ulna and Radius.

Phalanges and Metacarpals Each of the phalanges are extensions of a metacarpal that are labeled 1-5. The 1 st Metacarpal is the metacarpal that is an extension of the “Thumb”. They progress in order to the 5 th metacarpal which is an extension of the “pinkie” finger. Notice that, just like the “great toe”, there are only 2 phalanges that represent the thumb.

Carpal Bones The Carpal bones are strategically organized to allow a variety of movements at the wrist and to absorb force.

Scaphoid Bone The Scaphoid Bone is one of the biggest concerns for athletic trainers when evaluation a hand/wrist injury. The Scaphoid bone is the most commonly fractured bone in the hand. Most common Mechanism Of Injury (MOI) is FOOSH. (Fallen On Out Stretched Hand) The Scaphoid has limited blood supply in some areas, and can result in slow healing time, or the need for surgery to repair and speed up the healing process.

Hamate The Hamate Bone is found at the proximal, ulnar side of the Wrist. The hamate bone has a unique feature called the “hook” of the Hamate. The hook is a curved, hook-like process the projects 1– 2 cm distal and radial. Many ligaments come and attach to the “hook” of the Hamate. Due to the fact that it is a protuberance, if landed on directly, the hook is vulnerable for a possible fracture.

Hook of the Hamate Fracture

Forearm Bones The forearm consists of two bones: – Radius and the Ulna Radius: Located on the “thumb” side of the wrist. At the proximal portion of the forearm, the Radial Head is able to roll like a wheel on the Ulna to allow for supination and pronation of the wrist/forearm. Ulna: Makes up the boney part of your elbow, specifically known as the olecranon process.

Ulnar Nerve The ulnar nerve is a nerve that most of us are familiar with, and perhaps you don’t even know it. The Ulnar Nerve travels down the arm posteriorly, and eventually reaches the “Cubital Tunnel”, AKA the Ulnar Groove. At this location specifically, we call the ulnar nerve the “Funny Bone”

Supination and Pronation -The structure of the Radius and Ulna allow for movements that allow us to do a variety of different things with our hands. -The video below shows you how the Ulna and Radius roll over one another to create these movements: - atch?v=yhZ9ZX-Ht24https:// atch?v=yhZ9ZX-Ht24

Radius and Ulna

Carpal Tunnel The Carpal tunnel is formed by fibrous ligaments and retinaculum that allow a passageway for a couple tendons and a nerve. The Median Nerve is the nerve that travels through the carpal tunnel, and is the nerve that causes pain when that space is reduced.

TFCC TFCC stands for Triangular Fibro-Cartilage Complex. The entire “complex” is comprised of the triangular fibrocartilage discus (TFC), and various ligaments that connect the Ulna to the Radius, and the Ulna to various Carpal bones. Very similar to the role of either Meniscus of the Knees, and that of the Acetabular Labrum at the Hip Joint. Triangular fibrocartilage discus (TFC): a articular disc that provides cushioning to reduce force, as well as a smooth articular surface to reduce bone-to-bone rubbing.

TFCC Conditions Common Mechanism of Injury: -Severe and/or repeated Ulnar deviation. - -Special Test: -Piano Key Sign: -