Plate AT-B

Bones

Landmarks, fracture patterns, pressure points, and the cord levels that decide function.

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AT-B-29

In 3D: 25
Reviewed: 29
High yield: 19

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TEXT ONLY — NOT A SEPARATE PART OF THIS MODEL: Bone as tissue · Coccyx

Upper limb

5 structures

Upper limb

Carpals: scaphoid

The scaphoid is a boat-shaped wrist bone on the thumb side of the near row of carpals, lying in the floor of the anatomical snuffbox, and it is the carpal bone most often fractured.

Why the exam cares

After a fall on an outstretched hand, the nurse reports snuffbox tenderness even when the first X-ray is normal, because this fracture often does not show at first and a missed one can lose its blood supply. Once the thumb spica splint is on, the nurse checks circulation in the fingers and makes sure the client keeps the repeat-imaging visit.

How to find it

Ask the client to extend the thumb away from the hand. The hollow that opens at the base of the thumb, on the back of the wrist, is the anatomical snuffbox.
Its thumb-side ridge is two tendons (abductor pollicis longus and extensor pollicis brevis). Its other ridge is one tendon (extensor pollicis longus).
The scaphoid lies in the floor of that hollow, with the trapezium just beyond it. The radial pulse can also be felt in the same floor.
It sits just past the end of the radius, so it takes the force of a fall on the outstretched hand.

Assessment

Neurovascular checks under the thumb spica

Critical

Swelling under a rigid splint can cut off blood flow and press on nerves in the hand. The nurse checks the fingers for color, warmth, capillary refill, sensation, and movement, compares them with the other hand, and reports numbness, tingling, pale or cold fingers, or pain out of proportion to the injury right away. Before discharge the nurse teaches the client to elevate the hand above the heart, move the fingers often, and return at once for those same signs.

Fracture

Snuffbox tenderness with a normal X-ray

Watch

After a fall on the outstretched hand, the nurse presses gently into the floor of the snuffbox and reports tenderness to the provider even if the film is clear. The nurse expects a thumb spica splint and repeat imaging in about 10 to 14 days, and does not reassure the client that it is only a sprain.

Fracture

Why the follow-up visit matters

Watch

Blood enters the scaphoid at its far end and flows back toward the near end, so a fracture can starve the near piece of bone and it can die (avascular necrosis) or fail to heal. The nurse teaches the client to keep the splint on as instructed even if the wrist feels better, and confirms the follow-up appointment is scheduled and understood.

Reduction of Risk PotentialPhysiological Adaptation

Upper limb

Hand: metacarpals and phalanges

The hand's skeleton beyond the wrist is five metacarpals in the palm, whose rounded heads form the knuckles, and fourteen phalanges in the fingers: two in the thumb and three in each other finger.

Why the exam cares

After a hand is splinted or wrapped, the nurse checks every fingertip and acts right away on a pale, cool finger, slowed capillary refill, or new numbness or tingling, because the splint or swelling can cut off blood flow or press on a nerve. After a closed-fist injury, the nurse also looks for a tooth wound over the knuckle and reports it, because it is treated as a human bite.

How to find it

Ask the patient to make a fist: the knuckles that stand out are the heads of the metacarpals.
The fifth metacarpal runs along the little-finger edge of the hand to the smallest knuckle.
Each finger bends at two joints past the knuckle; the thumb bends at one.
The nail bed sits over the last phalanx of each digit and is where capillary refill is checked.

Assessment

Neurovascular check of the fingers

Critical

The nurse checks each fingertip for color, warmth, capillary refill (normally back within about 2 seconds), sensation on both sides, and the ability to bend and straighten, and compares with the other hand. A pale, cool fingertip or refill that has slowed since the last check means poor blood flow: the nurse loosens a tight outer wrap per facility policy and notifies the provider at once. New numbness, tingling, weakness, or pain that keeps rising or is not relieved by the ordered pain medicine is also reported promptly, because the splint or swelling may be pressing on nerves and blood vessels.

Fracture

Boxer fracture

Watch

A punch with a closed fist can break the neck of the fifth metacarpal and flatten the little-finger knuckle. The nurse asks how it happened and inspects the skin over the knuckle; a tooth wound there is reported to the provider because it is treated as a human bite, with cleaning and antibiotics, and can infect the joint. The nurse removes rings before swelling traps them, elevates the hand, and splints as ordered.

Procedure

Splinting in position of function

A resting hand splint holds the wrist slightly extended, the knuckles bent, the fingers gently curled as if holding a can, and the thumb out from the palm, never with the fingers flat, because knuckle joints held straight for a long time stiffen in a shape that cannot grip. A fracture splint may need a different position, so the nurse follows the provider's order. The nurse pads bony points and leaves the fingertips visible for checks.

Reduction of Risk PotentialBasic Care and Comfort

Upper limbHigh yield

Humerus

The humerus is the upper arm bone, running from the ball-shaped head at the shoulder down to the elbow.

Why the exam cares

After a fall on an outstretched arm, the nurse's repeated neurovascular checks catch the dangerous findings early: pain that keeps climbing and worsens when the fingers are stretched, a pale or cold hand in a child with a break just above the elbow, or a wrist that will not lift after a mid-shaft break or a tight cast. The deltoid injection is placed by finding the acromion first, so the needle stays out of the shoulder joint above and away from the radial nerve and brachial artery below.

How to find it

The acromion is the bony tip of the shoulder; the deltoid site starts two to three finger-widths below it and stays above the armpit line.
The surgical neck sits just below the head and the bumps of the tubercles; it is the usual break point in older adults, and the axillary nerve wraps around it.
The radial nerve runs in a groove on the back of the mid-shaft, so a mid-shaft break threatens wrist and finger extension.
Just above the elbow the bone thins (the supracondylar region), with the brachial artery and median nerve in front; the ulnar nerve runs behind the inner (medial) knob, the medial epicondyle.

Fracture

Supracondylar fracture in a child

Critical

A child who falls on an outstretched arm can break the humerus just above the elbow, where the brachial artery lies against the bone, so the nurse checks the radial pulse, capillary refill, color, warmth, sensation, and finger movement, and repeats the check after every splint, cast, or position change. A pale, cold hand or a fading pulse means the artery is pinched or injured; pain that keeps climbing despite ordered pain medicine and worsens when the fingers are passively stretched is the early sign of compartment syndrome, where a lost pulse is a late sign the nurse never waits for. For any of these findings the nurse loosens any tight dressing, keeps the arm at heart level rather than raised, and calls the provider at once, because delay can cost the forearm muscle.

Fracture

Proximal humerus fracture in older adults

In bone weakened by osteoporosis, a fall onto the hand or shoulder often breaks the humerus at the surgical neck. The nurse checks the radial pulse, feeling over the outer shoulder and the hand, and finger movement, then supports the arm in a sling. The nurse also starts fall-prevention and bone-health teaching, because the next fall may break a hip.

Nerve

Radial nerve and wrist drop

Watch

A mid-shaft break, a tight splint or cast, or an arm left hanging over a chair edge can press on the radial nerve. The nurse asks the patient to lift the wrist and straighten the thumb, and checks feeling on the back of the hand between the thumb and index finger. A wrist that has newly stopped lifting is reported promptly so the cast or arm position can be corrected before the nerve damage lasts.

Injection site

Deltoid injection site

Watch

The nurse finds the acromion, measures two to three finger-widths down, and injects at 90 degrees into the thickest center of the deltoid, above the armpit line. Too high, the needle can enter the shoulder bursa and joint and cause lasting shoulder pain and stiffness; too low, it risks the radial nerve and brachial artery. The site holds a small volume, about 1 mL in adults, so it is used for vaccines and other small doses, not large or irritating ones.

Reduction of Risk PotentialPhysiological AdaptationPharmacological and Parenteral Therapies

Upper limbHigh yield

Radius and ulna

The two bones of the forearm, running from elbow to wrist, with the radius on the thumb side and the ulna on the little-finger side.

Why the exam cares

A fall on an outstretched hand commonly breaks the wrist end of the radius, and the nurse's job after casting is to catch compartment syndrome early with repeated neurovascular checks. The radial artery runs along the lower radius, so this is also where the nurse counts a pulse and checks hand circulation before an arterial stick.

How to find it

The radial styloid is the bony knob on the thumb side of the wrist; the radial pulse is felt on the palm side, just toward the middle of the wrist from it, pressed gently against the radius.
The ulnar styloid is the bump on the little-finger side of the wrist, at the lower end of the ulna.
The point of the elbow (olecranon) is the top of the ulna. The ulnar nerve runs in a groove behind the bony knob on the inner side of the elbow, which belongs to the humerus (medial epicondyle), just beside the olecranon. Bumping that spot is what makes the little finger tingle.

Fracture

Colles fracture

Watch

A fall on the outstretched hand breaks the radius near the wrist and tips the fragment backward, so the wrist looks like a dinner fork from the side. The nurse splints the arm as found, elevates it, applies ice, removes rings before swelling traps them, and checks the fingers for color, warmth, capillary refill, sensation, and movement before and after reduction. In an older adult this break often points to osteoporosis, so the nurse expects bone-density follow-up and fall-prevention teaching.

Assessment

Cast checks and compartment syndrome

Critical

Each check compares the casted hand with the other hand: capillary refill under about 3 seconds, color, warmth, swelling, numbness, and finger movement. Pain out of proportion to the injury that worsens when the nurse passively stretches the fingers is the earliest sign of compartment syndrome, so the nurse reports it right away, because rising pressure can kill muscle and nerve within hours and a lost pulse is a late sign. While waiting for the provider, the nurse keeps the arm at heart level, not above it, since elevation lowers blood flow into a compartment that is already starved.

Pulse point

Radial pulse and the Allen test

Watch

The nurse counts the radial pulse with two fingertips for 30 seconds and doubles it when the rhythm is regular, or counts a full minute when it is irregular. Before a radial arterial blood gas, the nurse presses both the radial and ulnar arteries while the patient makes a tight fist, has the patient open the blanched hand, then releases only the ulnar artery. Color should return within about 7 seconds; if it does not, the ulnar artery may not supply the hand alone, so that radial artery is not punctured and the nurse notifies the provider.

Reduction of Risk PotentialBasic Care and Comfort

Upper limb

Scapula

The scapula is the shoulder blade, a flat triangular bone on the upper back that lies over ribs 2 to 7 and forms the shoulder socket at its outer corner.

Why the exam cares

Bone muffles breath sounds, so the nurse listens to the back of the lungs between the scapulae and below their lower tips, not over the bone. In a thin patient lying on the back, the scapular ridges are a common place for pressure injuries.

How to find it

The spine of the scapula is the hard ridge across the upper back. Its inner end sits about level with the T3 spinous process, and most of the lung heard below it from behind is lower lobe.
The inferior angle, the bottom tip, sits at about the T7 spinous process with the arms at the sides. The lung bases lie lower, near T10 in quiet breathing, so the nurse keeps listening below the tip.
Asking the patient to fold the arms across the chest pulls both scapulae outward and uncovers more lung between them.
The acromion is the bony point at the top of the shoulder, at the outer end of the scapular spine. The nurse measures down from it to find the deltoid injection site.

Auscultation

Posterior lung fields

The nurse sits the patient up with the arms crossed, starts above the scapulae at the apices, and works down between each scapula and the spine, comparing left with right at each level. The nurse finishes below the inferior angles at about T10 for the bases. A stethoscope placed on the bone picks up faint sound that is easy to chart wrongly as diminished breath sounds.

Landmark

Acromion for the deltoid site

The nurse palpates the acromion and measures 2 to 3 fingerbreadths down the outer arm into the thickest part of the deltoid. Injecting too close to the acromion can reach the shoulder joint and cause lasting shoulder injury; injecting too low risks the radial nerve and brachial artery.

Pressure point

Scapular ridges in the supine patient

In a thin, immobile patient lying on the back, the spine and inferior angle of the scapula press into the mattress with little tissue over them. The nurse inspects the upper back at every turn and uses a 30-degree side-lying tilt to take weight off the bone. Keeping the head of the bed at 30 degrees or lower when the condition allows reduces sliding and shear.

Reduction of Risk PotentialBasic Care and Comfort

Sources

Source	License
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 InternationalThe 3D plates. Modified: element meshes merged per structure, simplified, compressed, and recoloured for the web.	CC-BY-4.0
OpenStax Anatomy and Physiology 2e (CC BY 4.0)Informed the anatomical facts. The prose is original to this portal.	CC-BY-4.0
MedlinePlus / NIH	Public Domain (US Gov)
Nursing Nerds editorialEvery sentence in the atlas entries, each passed through independent clinical review.	Original