Picture a line in a patient file: “Swelling on the lateral side of the left knee.” Whose left is that, the writer's or the patient's? Anatomy answers with a single agreed rule, and that rule is the reason every course starts with the anatomical position.
Learn the anatomical position and directional terminology that grows out of it, and every later chapter gets easier to read. Skip it, and words like medial and distal will keep tripping you up all year.
Table of Contents
What Is the Anatomical Position, Exactly?
The anatomical position is the standard reference posture for describing the human body: standing upright, head and eyes facing forward, arms beside the body with palms facing forward, and feet together with toes pointing forward. Every directional term in anatomy assumes this pose, whatever position the person is actually in.
Think of it like a map. Every map agrees that north sits at the top, so nobody has to ask which way the page is facing. The anatomical position is the body's north.
Walk through the pose from the top. The head and eyes look straight ahead at the horizon. The arms hang by the sides, the palms face forward, and the thumbs point away from the body. The legs stay close together, with the feet parallel and the toes pointing forward. Figure 1 labels each feature.
Here's where most students slip, so slow down. Let your arms hang loose and your palms drift towards your thighs. That relaxed stance feels like the reference pose, but the pose asks for a single extra step: turn the palms to face forward.
Why bother with that extra step? Turning the palm forward (a forearm movement called supination) untwists the 2 forearm bones. The radius, the bone on the thumb side, then lies beside the ulna, the bone on the little-finger side, with no crossing. Turn the palm backwards and the radius crosses over the ulna, so the statement “the radius is lateral to the ulna” would stop being true. The extra step keeps a single description correct for every body.
Now the part that answers our opening problem. Left and right always belong to the person being described. Face a classmate and look at their right hand: it sits on your left.
A doubt always follows: the person might be lying on a bed, sitting, or curled on one side. The terms stay the same, because anatomists describe the body as if it stood in the reference pose. The chest side is still the front of the body (anterior) even in someone lying on their back (supine), and the back is still the back (posterior) even in someone lying face down (prone).
The pose earns its keep in physiotherapy as well. According to Norkin and White, the anatomical position is the zero starting position for measuring most joint ranges, so many goniometer (joint-angle protractor) readings you take later trace back to this pose.
With the pose fixed, every direction away from it needs a name. The names come in pairs, and the pairs come from just 3 lines.
Why Do Directional Terms Come in Pairs?
Directional terms come in pairs because the upright body has 3 lines you can travel along, and every line has 2 ends. Up and down give superior (higher, towards the head) and inferior (lower, towards the feet). Front and back give anterior and posterior. Side to side needs a reference line, the midline (an imaginary vertical line down the centre of the body), so medial means towards the midline and lateral means away from it.
Here are all 6 in one place. The table doubles as your revision sheet.
| Line | Term | Plain meaning | Also called | Example |
|---|---|---|---|---|
| Vertical | Superior | Higher, towards the head | Cranial | The head is superior to the neck. |
| Vertical | Inferior | Lower, towards the feet | Caudal | The umbilicus (navel) is inferior to the sternum. |
| Front to back | Anterior | Towards the front of the body | Ventral | The sternum is anterior to the heart. |
| Front to back | Posterior | Towards the back of the body | Dorsal | The heart is posterior to the sternum. |
| Side to side | Medial | Closer to the midline | None | The nose is medial to the ears. |
| Side to side | Lateral | Further from the midline | None | The eye is lateral to the nose. |
TeachMeAnatomy's 2024 guide to terms of location uses the heart and sternum to show how these words work: the heart is posterior to the sternum because it lies behind it. Flip the sentence and it stays true, since the sternum is anterior to the heart. Every position statement works in both directions, which gives you a quick self-test: if you can't flip it, you haven't understood it yet.
Medial and lateral cause a lot of slips, so use an anchor: medial sounds like middle, and whatever sits closer to the midline is medial to the other structure. Everything is relative, so the same eye gives 2 correct answers: the eye is lateral to the nose and medial to the ear. Always finish the sentence with a reference, such as medial to the nose or lateral to the ear.
Going deeper: ventral, dorsal, cranial, caudal and rostral
In humans, ventral and dorsal match anterior and posterior, while cranial and caudal match superior and inferior, because we stand upright. In four-legged animals the match breaks: the belly faces down, so ventral means towards the belly, and the cranial and caudal pair runs from head to tail. Human anatomy mostly keeps ventral and dorsal for embryology and neuroanatomy, where rostral (towards the nose end) also appears. The Terminologia Anatomica (1998) is the international standard vocabulary that anatomists use for the human body, so it is the reference to check when 2 textbooks disagree.
Those 6 words describe the head and trunk well. Limbs need a pair of their own, because limbs move and the trunk mostly stays put.
Proximal vs Distal: The Pair That Travels With the Limb
Proximal means closer to a structure's point of origin, and distal means further from it. Use them for anything with a beginning and an end, such as the upper limb, the lower limb, or a blood vessel.
Take the upper limb. Its point of origin is the shoulder, so the elbow is proximal to the wrist, and the wrist is distal to the elbow. In the lower limb the origin is the hip, so the knee is proximal to the ankle. Run a finger down your own arm from shoulder to fingertip and you have just travelled in the distal direction.
Superior and inferior answer one question: where is this on the standing body? Proximal and distal answer another: how far along this limb, counting from its root?
Here's the trap. In the reference pose the shoulder is superior to the hand, so proximal looks like a fancy word for superior. Raise your arm overhead and the illusion breaks: the hand now sits higher than the shoulder, yet it is still the distal end. Superior and inferior are tied to the standing pose, while proximal and distal are tied to the limb's own root. Figure 2 shows both positions side by side.
What happens if a report says “fracture of the distal radius” and the patient's arm was bent across the chest during the X-ray? Nothing changes: distal still points to the wrist end of the bone, away from the elbow. A report that said “lower end” would force the reader to hunt for a reference. That's why clinicians lean on proximal and distal for limbs.
So far every pair has described position along the body or along a limb. A few extra pairs describe depth and sides, and they hide some classic exam traps.
Depth, Sides, Palms and Soles: The Extra Pairs
Superficial means closer to the body surface, and deep means further inside, away from the surface. Think of it like an orange: the peel is superficial to the pulp, and the pulp is deep to the peel. In the body, the skin is superficial to the muscles beneath it.
Moore, Dalley and Agur describe external and internal as terms about nearness to the centre of an organ or cavity. That is a different job from superficial and deep, so keep the 2 sets apart in exam answers.
Ipsilateral means the same side of the body, and contralateral means the opposite side. A right wrist and a right knee are ipsilateral to each other, while a right wrist and a left knee are contralateral. A finding on both sides at once is bilateral, and in physiotherapy notes you will often see the affected limb compared with the contralateral one.
Hands and feet get surface names of their own, and the table below collects them with the other terms from this section.
| Term | Meaning | Quick example |
|---|---|---|
| Superficial | Closer to the body surface | The skin is superficial to the muscles. |
| Deep | Further from the body surface | The muscles are deep to the skin. |
| Ipsilateral | Same side of the body | Right wrist and right knee. |
| Contralateral | Opposite side of the body | Right wrist and left knee. |
| Bilateral | Both sides | Swelling of both ankles. |
| Palmar | Palm side of the hand | The palmar surface of the fingers. |
| Plantar | Sole of the foot | The plantar surface of the heel. |
| Dorsal (hand and foot) | Back of the hand, top of the foot | The dorsum of the foot. |
Everything so far names points: where one structure sits compared with another. Anatomists also cut the body, and the cuts have names too.
Sagittal, Coronal, Transverse: What Does Each Plane Cut?
A plane is an imaginary flat cut through the body in the anatomical position. The sagittal plane is vertical and runs front to back, which leaves you with left and right parts. A coronal plane is also vertical but runs side to side, giving front and back parts. A transverse plane is horizontal and separates upper from lower.
Sagittal has a story behind it. The name comes from the Latin word for arrow, through the sagittal suture of the skull, the seam that runs front to back along the midline. A sagittal cut that passes exactly through the midline is the median plane (also called the midsagittal plane), which gives 2 equal halves, as Moore, Dalley and Agur describe it. Any sagittal cut off to one side is parasagittal.
Coronal planes are also called frontal planes, and transverse planes are also called horizontal planes, or axial planes in imaging. Figure 3 shows all 3 cuts on a simple body block.
Kinesiology texts such as Neumann's use these same planes to classify joint movement, so the last column of the table below is worth a second look.
| Plane | Orientation | Divides the body into | Also called | Main movements |
|---|---|---|---|---|
| Sagittal | Vertical, runs front to back | Left and right parts | Median or midsagittal (through the midline); parasagittal (off to one side) | Flexion and extension, such as bending and straightening the elbow |
| Coronal | Vertical, runs side to side | Front and back parts | Frontal | Abduction and adduction, such as raising the arm out to the side |
| Transverse | Horizontal | Upper and lower parts | Horizontal; axial in imaging | Rotation, such as turning the head to look over your shoulder |
That puts every piece on the board. Time to use them on real sentences.
Using Directional Terminology on Real Anatomy Sentences
Quick pause. Here is what we hold so far: a fixed pose, 3 lines with 6 direction words, proximal and distal for limbs, the depth and side pairs, and 3 planes. Hold those, because now they start working together.
Start with the sentence from the opening: “Swelling on the lateral side of the left knee.” Decode it in order. Left means the patient's left, judged from the reference pose. Lateral means away from the midline, so the swelling sits on the outer side of that knee, the side facing away from the other leg.
Try a second line: “Tenderness over the palmar surface of the distal right forearm.” Right is the patient's right. Distal means towards the wrist end. Palmar means the palm-facing side in the reference pose. Three words, and you can point to the exact spot on a stranger's arm.
What happens if one word goes missing? Drop “left” and the reader must guess which limb to examine. Drop “lateral” and the reader must guess which side of the knee. Clinical notes spell out side and direction for exactly this reason, and an exam answer that does the same earns its marks.
Going deeper: a 4-point self-test
Cover the answers and say each term aloud: (1) the side the thumb sits on in the reference pose, (2) the wrist compared with the elbow, (3) the plane that separates front from back, (4) a right hand compared with a left foot.
Answers: lateral, distal, coronal, contralateral.
Once these words feel automatic, later chapters on muscle attachments and nerve courses read like plain description.
Anatomical position and directional terminology in 8 lines:
1. Anatomical position: upright, head and eyes forward, arms by the sides, palms forward, feet together and parallel, toes forward.
2. Forward palms untwist the forearm bones, so the radius is lateral and the ulna is medial.
3. Left and right belong to the person being described.
4. 3 lines, 6 words: superior and inferior, anterior and posterior, medial and lateral (near-equivalents: cranial and caudal, ventral and dorsal).
5. Proximal and distal follow the limb's root, while superior and inferior follow the standing body.
6. Superficial and deep describe distance from the surface; ipsilateral, contralateral and bilateral describe same, opposite and both sides.
7. Palmar is the palm side, plantar is the sole, and dorsal is the back of the hand or top of the foot.
8. Planes: sagittal (left and right), coronal (front and back), transverse (upper and lower); the median plane gives 2 equal halves.
Questions Students Ask About the Anatomical Position
What is the anatomical position in simple words?
It's the standard pose every anatomy description assumes: standing upright, eyes forward, arms by the sides with palms forward, feet together and parallel with toes forward. Anatomists always describe the body as if it were in this pose, even when the person is lying down or sitting. That way, a word like “anterior” means the same thing to everyone reading it.
Why are the palms turned forward in the anatomical position?
Forward palms untwist the 2 forearm bones. With the palm facing front, the radius lies on the thumb side and the ulna on the little-finger side, side by side. Turn the palm backwards and the radius crosses over the ulna, which scrambles descriptions like “the radius is lateral to the ulna”. The forward palm keeps one description true for every person, in every textbook.
In anatomy, does left mean the patient's left or the examiner's left?
Left and right always belong to the person being described. Face a patient and their right hand sits on your left, but the note still calls it the right hand. This holds even if the patient is lying down or turned away from you, because the description follows the body in the anatomical position. A note that says “left knee” always means the patient's left knee.
Are anterior and ventral the same thing?
In humans, yes: both mean towards the front of the body, because we stand upright. The two split apart in four-legged animals, where the belly faces down and ventral means towards the belly. In human anatomy you will mostly meet ventral and dorsal in embryology and neuroanatomy, while anterior and posterior dominate everyday descriptions.
What is the difference between proximal and superior?
Superior means higher on the standing body. Proximal means closer to a limb's point of origin, such as the shoulder for the arm. They agree when your arms hang by your sides, because the shoulder sits above the hand. Raise your arm overhead and they split: the hand is higher, but it stays distal. Proximal and distal follow the limb, wherever it goes.
What are the 3 anatomical planes?
Picture slicing a loaf. A vertical slice from front to back gives left and right parts, and that is the sagittal plane. Keep it vertical but cut side to side and the parts are front and back: the coronal plane. A flat horizontal slice gives upper and lower parts (transverse). Straight through the midline, a sagittal slice becomes the median plane, with 2 equal halves.
How can I remember which is medial and which is lateral?
Link medial to middle, since they sound alike and both point to the centre. Medial means closer to the midline, and lateral is the other one, further out towards the side. Then always finish the sentence with a reference. The eye is lateral to the nose but medial to the ear, so “medial or lateral” has no answer until you say “to what”.
This article is written for educational purposes for health-science students. It is not medical advice and never replaces clinical training, professional judgment, or your institution's curriculum. Real clinical decisions always require proper patient assessment under qualified supervision.
References
- Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. Wolters Kluwer.
- Neumann DA. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. Elsevier.
- Norkin CC, White DJ. Measurement of Joint Motion: A Guide to Goniometry. F.A. Davis.
- Federative Committee on Anatomical Terminology. Terminologia Anatomica: International Anatomical Terminology. Thieme; 1998.
- Jones O. “Anatomical Terms of Location.” TeachMeAnatomy. (2024).
