The Critical Body logo

Forearm Muscles, Bones and Anatomy

Your complete guide to the bones and muscles of the forearm.
Headshot of the Critical Body Personal Trainer Liam Brown
Written By Liam Brown
Last Updated on 19th March 2021
Diagram of the forearm extensor muscles
The forearm, which is sometimes referred to as the lower arm, is the region of the human body that lies between the elbow and the wrist. As you will see, however, many of the forearm muscles actually insert further down the upper limb into the hand because they’re responsible for flexing and extending the fingers.

The forearm muscles consist of flexors, which lie in the anterior compartment of the forearm, and the extensors, which lie in the posterior compartment [1]. The muscles of the forearm also consist of supinators, which turn the palm down, and pronators, which turn the palm up. Additionally, the brachioradialis is another forearm muscle, one which flexes the elbow.

Anatomically speaking, the term arm refers to the upper arm only, hence why forearm is a more correct term than lower arm.

The forearm anatomy consists of two elongated bones that run parallel to each other; the ulna, which lies medially; and the radius, which lies laterally. Together, these two bones form the radioulnar joint, which permits supination and pronation of the forearm.

Skin covers these bones, and most people have a higher quantity of hair on the top of their forearm (the posterior compartment) than on the underside (anterior compartment).

The ulnar and radial arteries supply blood to the forearm. The radial artery supplies blood to the posterior and lateral part of the forearm anatomy, while the ulnar artery supplies blood to the anterior and medial aspects [2].

Forearm muscles

Anatomy of the arm
The muscles of the forearm are split into two distinct compartments; the anterior compartment, which contains the flexors; and the posterior compartment, which contains the extensors.

The radial nerve supplies the extensor muscles, which are naturally weaker than the opposing flexors, while the median nerve supplies the flexor muscles [3].

Forearm flexors

The forearm muscles in the anterior compartment flex the forearm, wrist, and fingers. They also perform pronation, which is to say turning the palm down [4]. They’re divided into three layers; superficial muscles, which lie close to the skin; deep muscles, which lie near to the bones (radius and ulnar) or internal organs; and intermediate muscles, which lie between the superficial and deep forearm muscles.

These lower arm muscles are:

Flexor Carpi Radialis (superficial)
Flexor Carpi Ulnaris (superficial)
Pronator Teres (superficial)
Palmaris Longus (superficial)
Flexor Digitorum Superficialis (superficial/intermediate)
Flexor Pollicis Longus (deep)
Flexor Digitorum Profundus (deep
Pronator Quadratus (deep)

Forearm extensors

The forearm extensors function to extend the wrist and fingers and are separated into two layers; superficial and deep. While there are only 8 forearm flexor muscles, there are 12 unique forearm extensor muscles, 5 of which originate at the lateral epicondyle of the humerus.

The extensor muscles in the forearm are:

Extensor Carpi Radialis Longus (superficial)
Extensor Carpi Radialis Brevis (superficial)
Extensor Carpi Ulnaris (superficial)
Extensor Digitorum (superficial)
• Extensor Digiti Minimi (superficial)
Anconeus (superficial)
• Brachioradialis (superficial)
Extensor Pollicis Brevis (deep)
• Extensor Pollicis Longus (deep)
• Extensor Indicis Proprius (deep)
• Abductor Pollicis Longus (deep)
• Supinator (deep)

Forearm bones

A diagram of the ulna forearm bone
Proximally, at the elbow joint, the ulna articulates the humerus.

Distally, it forms a synovial pivot joint with the radius, which allows for pronation and supination. This joint is known as the radioulnar joint, and it helps to keep the ulna and radius together when we move our forearm.

The radius has more articulation points than the ulna. Proximally, at the elbow joint, it articulates with the capitulum of the humerus and the radial notch of the ulna.

Distally, the radius articulates between the carpal bones, the lunate (medially), and the scaphoid (laterally). As mentioned, the radius also articulates with the semilunar notch at the radioulnar joint.


  1. Mitchell, B., & Whited, L. (2020). Anatomy, Shoulder and Upper Limb, Forearm Muscles. StatPearls Publishing LLC.
  2. Wikipedia contributors. (n.d.). Forearm. Wikipedia.
  3. Boles, C. A., Kannam, S., & Cardwell, A. B. (2000). The Forearm. American Journal of Roentgenology, 174(1), 151–159.
  4. Muscles of the Anterior Forearm - Flexion - Pronation. (2020, August 15). TeachMeAnatomy.

Step-by-step workouts

Fitness model flexing his armBest forearm exercises and workout routines
All the equipment you need to do proper forearm exercise at homeForearm workouts at home without weights
A man's muscular forearmBodyweight forearm exercises for calisthenics
Man performing a seated dumbbell forearm curlDumbbell forearm exercises and workouts
Man performing a rope hammer curlBrachioradialis Exercises and workout

A bodybuilder showing his big vascular forearmHow to get bigger forearms naturally
Man performing bicep and forearm exerciseBicep and forearm workout routines
Man performing an arm workoutBicep, tricep, and forearm workouts

Shoulder and forearm workoutShoulder and forearm workout

A man performing kettlebell wrist curlsKettlebell forearm exercises and workout
A man performing a backpack wrist curlForearm workout with a backpack

Woman holding pink dumbbellsForearm workout for women

Man performing a reverse grip wrist curlForearm extensor exercises
A man performing resistance band forearm curlsResistance band forearm exercises

Toned woman in the gymHow to tone your forearms

Exercise drills

A person doing the dumbell wrist curl exerciseDumbbell wrist curl
Man doing wrist curls with a barbellBarbell wrist curl

A man using a forearm rollerWrist roller

A man doing a reverse dumbbell wrist curlReverse dumbbell wrist curl
Man performing a reverse wrist curl with a barbellReverse barbell wrist curl

A demonstration of the start and end positions for the behind the back wrist curl exerciseBehind the back wrist curl

A man doing a standing barbell wrist curlStanding wrist curl
Man performing a standing reverse wrist curlStanding reverse wrist curl

A man performing behind the back resistance band wrist curlsCable wrist curl

Person doing single arm dumbbell wrist curlsSingle dumbbell wrist curl
The end position of a plate wrist curlPlate wrist curl

A man doing a reverse forearm curlPalms down dumbbell wrist curls

The start and end positions for the forearm twist exerciseForearm twist exercise

Three EZ curls bar of various weightsEZ bar wrist curl

Stretches and rehab

Female runner stretching her handBest forearm stretches
The brachioradialis anatomyBrachioradialis stretch drills

Man performing some forearm myofascial releaseForearms myofascial release

A man doing a dumbbell wrist flexion exerciseDumbbell wrist flexion
Man doing a dumbbell wrist extension over a deskDumbbell wrist extension

Physiotherapist touching a woman's handSupinator stretch

Woman with her palms downForearm pronation and supination exercises
Senior woman with forearm painForearm rehabilitation exercises

A man doing dumbbell wrist extensionsEccentric forearm exercises

Common forearm problems

Woman with forearm tendonitisBrachioradialis pain after lifting
Man in the gym with an injuryForearm pain when lifting weights

A man performing a hardcore bicep workout with his spotterForearm pain when curling

Man holding his forearmForearm splints
Woman with forearm painForearms strains

Man with a painful forearmForearm cramping

Woman with a painful armTight forearms
Asian senior woman holding a handrailWeak forearms

Female runner looking tired and sweatingSweaty forearms

Skinny guy in a white vestSkinny forearms
Overweight woman drinking water in the gymFat forearms

Injured tennis playerTennis forearm pain

Woman with a strained forearm muscleForearm pain when gripping
The word fibromyalgia written on a screenFibromyalgia and forearm pain

Happy couple playing video gamesForearm pain from gaming

Woman with wrist pain from typingForearm pain from typing
Woman doing chin ups in the parkForearm pain from pull ups

Sporty woman holding a kettlebellKettlebell hitting forearm

A comparison of two men's armsBig biceps but small forearms
A man and a woman arm wrestlingOne forearm bigger than the other

Woman using a rowing machine outsideForearm hurts from rowing

Forearm products

Two hand grip trainersForearm exercise equipment
A wrist roller device for the forearmsWrist roller

Woman wearing a forearm braceforearm brace

A white forearm sleeveForearm compression sleeve
Man with tape on his armForearm strapping

Man wearing an elbow sleeveForearm weights

Person performing the wrist roller exerciseForearm blaster

A forearm compression sleeveForearm wraps

A wrist curl machine for working the forearm musclesWrist curl machine

The Grip Freak Hanging Wrist RollerGrip Freak Hanging Wrist Roller

The Rogue wrist roller in actionRogue Wrist Roller

DIY toolsDIY homemade Wrist roller

The Vikingstrength Wrist Roller in actionVikingstrength Forearm Blaster

GD wrist rollerGD Wrist Roller

The Pellor Wrist Roller and its packagingPellor Wrist Roller

The SideWinder Grip TwisterSidewinder Grip Twister

Image showing the Sidewinder Pro Xtreme wrist rollerSidewinder Pro Xtreme
An image showing the Sidewinder Pro PlusSidewinder Pro Plus

The SideWinder RevolutionSidewinder Revolution

The IronMind Twist Yo' Wrist featured imageIronMind Twist Yo Wrist

The IronMind One Wicked Wrist Roller featured imageIronMind Wrist Roller

The 4Arm Strong Arm Pump Device4Arm Strong

Man using a hand squeezer in the carBlack Diamond Forearm Trainer

The Marcy wrist and forearm developer in actionMarcy Wrist and Forearm Developer

The Bison-1M Forearm exerciserBison-1M Forearm Exerciser

The Core Prodigy Wrist Blaster featured imageCore Prodigy Wrist Blaster

Sports-specific articles

Muscular man holding a baseball batBaseball forearm workouts

A bucket of white riceRice bucket workout

Tennis player on the courtTennis forearm exercises

Muscular man doing indoor rock climbingRock climbing forearm workout

White rice in a wooden bucketRice bucket exercises for climbing

A man and a woman arm wrestlingForearms exercises for arm wrestling

Advanced forearm guides

Bodybuilder flexing his forearmForearm hypertrophy strategy guide

A forearm compression sleeveForearm occlusion training

A forearm before and after transformationThe forearm transformation guide

A muscular arm holding a dumbbellArnold Schwarzenegger forearm workout

A muscular man showing his fistsBruce Lee forearm training

A bodybuilder flexing his armPhil Heath forearms workout

A muscular man holding a dumbbell in his handThe Sylvester Stallone forearms guide
A man working out on the Total GymTotal Gym forearm exercises

Man working out on a TRXTRX forearm exercises

Forearm FAQs

Senior Asian couple folding their armsWhat is the average forearm size?

A bodybuilder's forearmWho has the biggest forearms in the world?
Fitness model showing his fistHow to get bigger forearms and wrists

A large forearms positioned next to a skinny man's armCan you build forearms bigger than your biceps?
Two guys showing their forearms musclesHow to get forearm veins
Man doing elevated push upsDo pushups work your forearms?

Man doing dumbbell curlsDo bicep curls work your forearms?
Man performing wide grip pull ups in the parkDo pull ups work your forearms?
Man performing a powerlifting bench pressDoes bench press work your forearms?

Powerlifting gripping a barbell in preperation for the deadliftDoes the deadlift work your forearms?
A man with wrist pain at the gymAre wrist curls bad?
Can you train forearms everyday featured imageCan you workout forearms everyday?

An image depicting the foot forearm correlationIs your foot as long as your forearm?
Are forearm exercises necessary featured imageHow often can you train forearms?
Are forearm exercises necessary featured imageAre forearm exercises necessary?

Two hands holding each otherWhat is the opposite of forearm?
A bodybuilder showing his veiny forearmWhy are Popeye's forearms so huge?
Overweight senior stroking her chinWhy do we get forearm and elbow creases?
Four human forearms and fistsWhat are considered long forearms?
A forearm and clenched fistArm vs forearm: What's the difference?
A barbell rack with bars of various weightsWhat's a good wrist curl weight?
Two men performing the Spartan handshake from Roman times, clasping one another's forearmsWhat's the significance of the forearm handshake?
Man adjusting his sleevesDo girls like men's forearms?
Muscular blacksmith holding a hammerWhat's the deal with blacksmith's forearms?
Man performing a wrist curlWhat are some good wrist curl alternatives?
Skinny man flexing his musclesAre 11 inch forearms normal?
veiny male forearmAre 12 inch forearms good?
Vascular male forearmsAre 13 inch forearms impressive?
A man's muscular forearmHow big are 14 inch forearms?
Close up of a man's fist and forearmHow to get 15 inch forearms
A bodybuilder's massive forearmCan you get 16 inch forearms naturally?
Bodybuilder flexing his armWho has 19 inch forearms?
Bodybuilder flexing his forearmHas anyone got 20 inch forearms?