Forearm Anatomy, Carpal Bones, and Common Musculoskeletal Injuries

Vocabulary based on the lecture regarding forearm anatomy, wrist structures, hand bones, and clinical injury classifications.

Study Groups

A learning strategy used to identify what you do not know through asking each other questions and achieving self-realization of knowledge gaps.

Radius

The lateral bone of the forearm characterized by a circular head, representing the distance from the center of a circle to its edge.

"That's rad"

A mnemonic device where giving a thumbs up helps identify the radius, as the bone follows the thumb back to the forearm.

Ulna

The medial bone of the forearm that forms the point of the elbow and contains a U-shaped notch.

Trochlear notch

A U-shaped landmark on the ulna that hugs the trochlea of the humerus.

Process

A general anatomical term for a landmark or piece of bone that sticks out.

Styloid process

A pointed landmark found on the distal ends of both the radius and the ulna, named after the Latin word for pen (stylus).

Semicolon ($;$)

A shorthand notation used during exams to mean "of the" when identifying specific landmarks on a bone.

Carpal

A term referring to the bones of the wrist; there are $8$ carpal bones in total.

Scaphoid

A carpal bone located on the thumb side, named after the word "skiff" because it resembles a boat without a sail.

Lunate

A carpal bone shaped like a crescent moon, named after the word "lunar."

Meta

A prefix meaning "beyond."

Metacarpals

The five bones located beyond the wrist that make up the palm of the hand, numbered $I$ through $V$ using Roman numerals starting from the thumb.

Phalanges

The plural term for the bones of the fingers, named after the way ancient Roman armies were organized into units.

Phalanx

The singular term for a finger bone, categorized as proximal, middle, or distal.

Thumb

A digit that only contains two phalanges (proximal and distal) and lacks a middle phalanx.

Dislocated shoulder

An injury where the head of the humerus disarticulates with the glenoid fossa of the scapula.

Separated shoulder

An injury where the acromion process of the scapula disarticulates with the clavicle.

Free floating bone

A description of the scapula, which is wired down in laboratory models but must be mobile in the body to allow for shoulder range of motion.

Broken clavicle

Also known as a broken collarbone; it is more common than a broken scapula because impact forces on the shoulder are transferred to this bone.

Separated elbow

A joint injury common in toddlers and children because their elbows are still malleable and not fully developed.

Broken wrist (Forearm)

A fracture of the distal radius and ulna typically caused by landing at an angle to brace a fall; it heals in about $6-8$ weeks.

Broken wrist (Carpal)

A fracture of the scaphoid and lunate typically caused by falling straight down; it can take $6-8$ months to heal due to limited blood supply.

Nutrient foramen

Openings in the bone for blood vessels; their abundance in long bones versus cuboidal bones explains why long bones heal faster.