Muscle Library

The Muscle Library, A–Z

Every muscle page in the library, alphabetically. Each covers where that muscle sends pain, what the pattern feels like, what it gets mistaken for, and how that muscle is examined and treated. If you know where it hurts but not which muscle, start with the Pain Finder instead. For the acupuncture points and motor points used on these muscles, see the Orthopedic Points reference.

By Region

The seven regions of the Pain Finder, each with every muscle in the library for that region. The full list, A to Z, follows below.

Head & Neck

Upper Trapezius: Pain climbs the side of the neck to the temple and behind the eye.

Sternocleidomastoid: Pain sits over the eye and in the ear, with dizziness on turning the head.

Suboccipitals: Pain runs from the base of the skull through the head to the eye.

Levator Scapulae: Pain at the corner of the neck and shoulder restricts turning the head to look behind.

Scalenes: Pain from the neck sends heaviness or tingling down the arm to the thumb side of the hand.

Temporalis: Pain throbs in the temple, and the upper teeth ache and react to cold.

Masseter: Pain fills the jaw and ear, and the lower teeth ache with chewing.

Splenius Capitis: Pain sits on the top of the head on one side.

Splenius Cervicis: Pain presses behind one eye, with blurred vision on that side.

Semispinalis Capitis: Pain bands around the side of the head, and the scalp burns or hurts to touch.

Longus Colli and Longus Capitis: Pain sits deep in the front of the neck, and the head is hard to lift from the pillow.

Digastric: Pain sits behind the ear, the lower front teeth ache, and the throat feels like it holds a lump.

Medial Pterygoid: Pain aches deep in the ear and hurts on swallowing, even with a clear ear exam.

Lateral Pterygoid: Pain sits deep in the jaw joint, and the jaw clicks and drifts to one side on opening.

Occipitofrontalis: Pain sits above one eyebrow, and the back of the head hurts to rest on a pillow.

Orbicularis Oculi: Pain aches along the side of the nose, and the lower eyelid twitches constantly.

Zygomaticus and Buccinator: Pain runs from beside the nose up the forehead, and the cheek aches chewing.

Platysma: Pain prickles on the skin of the jaw and chin, on the surface and not inside.

Shoulder & Upper Back

Infraspinatus: Pain sits deep in the front of the shoulder and stops the hand from reaching behind the back.

Supraspinatus: Pain aches deep in the shoulder cap when the arm lifts out to the side.

Subscapularis: Pain in the back of the shoulder restricts lifting and turning the arm, and a band of ache reaches the wrist.

Deltoid: Pain sits on the shoulder cap itself and appears in one direction of lifting.

Rhomboids: Pain burns at one spot between the shoulder blade and the spine.

Scalenes: Pain from the neck sends heaviness or tingling down the arm to the thumb side of the hand.

Teres Minor: Pain sits in one deep spot at the back of the shoulder, the size of a coin.

Teres Major: Pain aches deep at the back of the shoulder when reaching up and forward.

Latissimus Dorsi: Pain aches steadily at the lower tip of the shoulder blade, and no position changes it.

Middle Trapezius: Pain burns between the shoulder blade and the spine when the shoulders round forward.

Lower Trapezius: Pain aches deep at the top of the shoulder blade and returns within a day of massage.

Pectoralis Minor: Pain sits at the front of the shoulder, and the ring and little fingers go numb when the arm is raised.

Subclavius: Pain runs from the collarbone down the arm to the thumb, skipping the elbow and wrist.

Serratus Posterior Superior: Pain aches deep under the shoulder blade where nothing can reach.

Coracobrachialis: Pain sits at the front of the shoulder and down the back of the arm at the same time.

Arm & Hand

Triceps: Pain aches deep down the back of the arm into the outer elbow.

Brachioradialis: Pain at the outer elbow comes on with gripping and runs along the top of the forearm.

Forearm Extensor Group: Pain at the outer elbow comes on with twisting a jar lid and reaches the back of the wrist.

Forearm Flexor Group: Pain at the inner elbow reaches the palm-side wrist, and the fingers feel tight in the morning.

Thumb Muscles: Pain at the base of the thumb comes on with pinching and weakens the grip on a pen or a key.

Abductor Pollicis Longus, Extensor Pollicis Longus and Brevis: Pain at the thumb side of the wrist comes on with lifting and twisting the hand.

Biceps Brachii: Pain sits at the front of the shoulder close to the surface and worsens reaching overhead.

Brachialis: Pain at the base of the thumb comes from the upper arm, and the back of the thumb goes numb.

Anconeus: Pain sits at the bony point of the outer elbow and stays in that one spot.

Supinator: Pain at the outer elbow comes on with turning a doorknob and reaches the thumb web.

Pronator Teres: Pain aches deep in the front of the forearm, and the palm goes numb.

Palmaris Longus: Pain prickles in the middle of the palm when gripping a wheel or a tool.

Extensor Carpi Radialis Longus and Brevis: Pain at the back of the wrist comes on with gripping, and the hand drops what it holds.

Extensor Digitorum: Pain runs down the back of the forearm into one finger, and the fingers are stiff on waking.

Extensor Indicis: Pain aches on the back of the hand behind the index finger.

Flexor Carpi Radialis: Pain at the front of the wrist on the thumb side comes on when the hands bear weight, as in a push-up.

Flexor Carpi Ulnaris: Pain at the front of the wrist on the little-finger side comes on with wringing out a towel.

Flexor Pollicis Longus: Pain aches in the thumb pad and tip after writing or texting.

Interossei of the Hand: Pain runs along the side of one finger from the knuckle to the tip.

Lumbricals of the Hand: Pain aches along the side of one finger after writing, and the hand will not flatten.

Hypothenar Muscles: Pain aches at the outer edge of the palm when holding a phone one-handed.

Torso & Abdomen

Pectoralis Major: Pain in the chest worsens when the arm moves and spreads down the inner arm.

Serratus Anterior: Pain holds on the side of the ribs like a stitch and sharpens on a deep breath.

Rectus Abdominis: Pain bands across the back at belt height with a normal spine exam.

Abdominal Obliques: Pain reaches the groin with no hernia found, or burns like heartburn that antacids do not relieve.

Sternalis: Pain sits deep and steady behind the breastbone, and breathing does not change it.

Intercostals: Pain stabs in one rib space on a deep breath.

Diaphragm: Pain stitches under the lower ribs on a full breath, and the top of the shoulder aches on the same side.

Transversus Abdominis: Pain bands across the upper abdomen when coughing or bracing.

Pyramidalis: Pain sits in the midline just above the pubic bone and worsens sitting up from lying.

Iliocostalis Thoracis: Pain sits beside the mid-back spine and wraps around the ribs to the front of the chest.

Serratus Posterior Inferior: Pain aches over the lower back ribs and stays in one spot.

Iliopsoas: Pain in the low back stops the body from standing fully upright after sitting, with a pinch at the front of the hip.

Erector Spinae: Pain bands across the back as stiffness and eases once moving.

Low Back & Hip

Quadratus Lumborum: Pain grabs the low back on standing up and on rolling over in bed.

Gluteus Medius: Pain aches along the belt line and into the outer buttock, worst lying on that side at night.

Gluteus Minimus: Pain runs down the leg like sciatica with no numbness, worst rising from a chair.

Piriformis: Pain aches deep in the buttock and worsens with sitting.

Iliopsoas: Pain in the low back stops the body from standing fully upright after sitting, with a pinch at the front of the hip.

Erector Spinae: Pain bands across the back as stiffness and eases once moving.

Gluteus Maximus: Pain aches deep in the buttock after long sitting, and the tailbone feels bruised.

Obturator Internus: Pain sits between the tailbone and the anus, with a feeling of fullness in the rectum.

Obturator Externus: Pain feels inside the hip joint and is worst getting out of a car.

Quadratus Femoris and Gemelli: Pain sits deep beside the sit bone, lower than the piriformis, and is worst sitting.

Iliocostalis Lumborum: Pain sits in the low back and the buttock together on the same side.

Longissimus Thoracis: Pain sits in the buttock, but the tender spot is higher up the back.

Multifidi: Pain sits in one deep spot beside the spine and feels like pain in the bone.

Rotatores and Deep Paraspinals: Pain sits at one level of the spine, and that level catches when turning.

Levator Ani and Coccygeus: Pain at the tailbone worsens sitting, with a normal X-ray.

Thigh & Knee

Quadriceps: Pain at the front of the knee worsens going down stairs, and the knee can buckle without swelling.

Rectus Femoris: Pain aches deep in the kneecap at night and worsens going down stairs.

Vastus Lateralis: Pain runs down the outer thigh to the knee, the kneecap sticks, and lying on that side hurts.

Vastus Medialis: Pain aches at the inner front of the knee, and the knee gives out on stairs.

Vastus Intermedius: Pain aches in the front of the thigh rather than the knee, and the knee will not straighten after sitting.

Hamstrings: Pain aches in the back of the thigh on sitting, and the knee is tight to straighten.

Biceps Femoris: Pain aches at the back of the knee on sitting and runs up the outer back of the thigh.

Semitendinosus and Semimembranosus: Pain at the sit bone worsens sitting and runs down the inner back of the thigh.

Tensor Fasciae Latae (TFL): Pain aches at the outer hip lying on that side and runs down the outer thigh.

Adductor Group: Pain pulls in the groin, keeps returning, and reaches the inner knee.

Sartorius: Pain tingles sharply along the inner thigh, in the skin rather than the muscle.

Pectineus: Pain sits deep in the groin at the crease at the top of the thigh.

Gracilis: Pain stings in a hot line down the inner thigh, and no position relieves the line.

Popliteus: Pain sits right behind the knee and is worst walking downhill.

Leg, Ankle & Foot

Gastrocnemius: Pain cramps the gastrocnemius at night, and the instep aches after running.

Soleus: Pain in the heel is worst on the first steps of the morning.

Plantaris: Pain sits behind the knee and runs down toward the gastrocnemius, often after a sprint or a jump.

Tibialis Anterior: Pain runs along the front of the shin, and the big toe hurts to lift.

Tibialis Posterior: Pain runs along the Achilles line on uneven ground, and tendon treatment did not touch the pain.

Peroneal Group: Pain at the outer ankle holds on long after a sprain, and the ankle rolls easily.

Peroneus Tertius: Pain sits at the front of the ankle and the outer heel, and the sprain never healed.

Extensor Digitorum Longus: Pain aches on the top of the foot in tight shoes, and the foot catches on steps.

Extensor Hallucis Longus: Pain sits on the top of the foot at the big toe and worsens in a tight shoe.

Flexor Digitorum Longus: Pain aches in the ball of the foot and the toes with every step on a hard floor.

Flexor Hallucis Longus: Pain sits under the big toe when pushing off to walk or run.

Deep Foot Muscles: Pain aches in the arch and burns in the ball of the foot.

Extensor Digitorum Brevis and Extensor Hallucis Brevis: Pain sits in one coin-sized spot on top of the foot in front of the ankle.

Flexor Digitorum Brevis: Pain burns across the ball of the foot on standing and feels like a pebble in the shoe.

Abductor Hallucis: Pain runs along the inner side of the heel rather than under the heel.

Adductor Hallucis: Pain sits deep across the ball of the foot, which feels thick and numb, worst in narrow shoes.

Flexor Hallucis Brevis: Pain under the ball of the big toe prevents rising onto the toes.

Abductor Digiti Minimi (Foot): Pain sits under the little toe at the outer edge of the foot and worsens in narrow shoes.

Interossei of the Foot: Pain runs along one toe with nothing found, and the forefoot cramps in bed.

Lumbricals of the Foot: Pain runs under one toe, the toes cramp at night, and one toe has started to curl.

A to Z

A

Abdominal Obliques: Pain reaches the groin with no hernia found, or burns like heartburn that antacids do not relieve.

Abductor Digiti Minimi (Foot): Pain sits under the little toe at the outer edge of the foot and worsens in narrow shoes.

Abductor Hallucis: Pain runs along the inner side of the heel rather than under the heel.

Abductor Pollicis Longus, Extensor Pollicis Longus and Brevis: Pain at the thumb side of the wrist comes on with lifting and twisting the hand.

Adductor Group: Pain pulls in the groin, keeps returning, and reaches the inner knee.

Adductor Hallucis: Pain sits deep across the ball of the foot, which feels thick and numb, worst in narrow shoes.

Anconeus: Pain sits at the bony point of the outer elbow and stays in that one spot.

B

Biceps Brachii: Pain sits at the front of the shoulder close to the surface and worsens reaching overhead.

Biceps Femoris: Pain aches at the back of the knee on sitting and runs up the outer back of the thigh.

Brachialis: Pain at the base of the thumb comes from the upper arm, and the back of the thumb goes numb.

Brachioradialis: Pain at the outer elbow comes on with gripping and runs along the top of the forearm.

C

Coracobrachialis: Pain sits at the front of the shoulder and down the back of the arm at the same time.

D

Deep Foot Muscles: Pain aches in the arch and burns in the ball of the foot.

Deltoid: Pain sits on the shoulder cap itself and appears in one direction of lifting.

Diaphragm: Pain stitches under the lower ribs on a full breath, and the top of the shoulder aches on the same side.

Digastric: Pain sits behind the ear, the lower front teeth ache, and the throat feels like it holds a lump.

E

Erector Spinae: Pain bands across the back as stiffness and eases once moving.

Extensor Carpi Radialis Longus and Brevis: Pain at the back of the wrist comes on with gripping, and the hand drops what it holds.

Extensor Digitorum: Pain runs down the back of the forearm into one finger, and the fingers are stiff on waking.

Extensor Digitorum Brevis and Extensor Hallucis Brevis: Pain sits in one coin-sized spot on top of the foot in front of the ankle.

Extensor Digitorum Longus: Pain aches on the top of the foot in tight shoes, and the foot catches on steps.

Extensor Hallucis Longus: Pain sits on the top of the foot at the big toe and worsens in a tight shoe.

Extensor Indicis: Pain aches on the back of the hand behind the index finger.

F