Muscles
Browse muscles with trigger-point locations, referred pain patterns and clinical notes.
94 results
Foot
Abductor hallucis
Abducts and flexes the big toe; supports the medial arch.
Shoulder
Abductor pollicis
Thenar muscle; abducts the thumb.
Hip
Adductor longus
Adducts and flexes the hip.
Hip
Adductor magnus
Adducts and extends the hip.
Shoulder
Adductor pollicis
Adducts the thumb toward the index finger.
Shoulder
Anterior deltoid
Flexes and internally rotates the shoulder.
Shoulder
Biceps brachii
Flexes the elbow and supinates the forearm; assists shoulder flexion.
Leg
Biceps femoris
Hamstring extending the hip and flexing the knee.
Shoulder
Brachialis
Primary elbow flexor regardless of forearm rotation.
Shoulder
Brachioradialis
Flexes the elbow with the forearm in neutral.
Shoulder
Coracobrachialis
Flexes and adducts the shoulder.
Back
Diaphragm
Primary muscle of inspiration; influences trunk and pelvic floor function.
Head
Digastric
Two-bellied suprahyoid that opens the jaw and elevates the hyoid during swallowing.
Shoulder
Extensor carpi radialis
Extends and radially deviates the wrist.
Shoulder
Extensor digitorum
Extends the fingers and assists wrist extension.
Foot
Extensor digitorum brevis
Extends the medial four toes.
Leg
Extensor digitorum longus
Extends toes 2–5; dorsiflexes the ankle.
Leg
Extensor hallucis longus
Extends the big toe; dorsiflexes the ankle.
Back
External oblique
Side-bends and rotates the trunk; flexes the trunk.
Shoulder
Flexor carpi radialis
Flexes and radially deviates the wrist.
Foot
Flexor digitorum brevis
Flexes the proximal IP joints of toes 2–5.
Leg
Flexor digitorum longus
Flexes toes 2–5; assists plantarflexion and inversion.
Shoulder
Flexor digitorum superficialis
Flexes the proximal interphalangeal joints of fingers 2–5.
Leg
Flexor hallucis longus
Flexes the big toe; supports push-off.
Shoulder
Flexor pollicis longus
Flexes the thumb's interphalangeal joint.
Foot
Foot interossei
Spread and stabilize the toes during push-off.
Head
Frontalis
Anterior belly of the occipitofrontalis; raises the eyebrows and wrinkles the forehead.
Leg
Gastrocnemius
Plantarflexes the ankle; flexes the knee.
Hip
Gluteus maximus
Powerful hip extensor and external rotator; the largest muscle in the body.
Hip
Gluteus medius
A leading cause of lateral hip pain and 'low back' pain that doesn't respond to spinal treatment.
Hip
Gluteus minimus
Hip abductor and stabilizer; deepest of the gluteal group.
Hip
Gracilis
Adducts the hip and flexes the knee.
Back
Iliocostalis lumborum
Erector spinae extending the lumbar spine; assists side bending.
Hip
Iliopsoas
Primary hip flexor; psoas major also influences lumbar lordosis.
Shoulder
Infraspinatus
The most common rotator cuff source of deep anterior shoulder pain — pain felt at the front but coming from the back of the scapula.
Back
Intercostal muscles
Move ribs during breathing and stabilize the rib cage.
Back
Internal oblique
Rotates the trunk to the same side; assists trunk flexion.
Head
Lateral pterygoid
Protrudes and opens the jaw; the only muscle that meaningfully depresses the mandible.
Back
Latissimus dorsi
Extends, adducts and internally rotates the shoulder; pulls the trunk to a fixed arm.
Neck
Levator scapulae
Classic cause of the 'stiff neck' that won't rotate — sharp pain at the angle of the neck and shoulder.
Back
Longissimus thoracis
Erector spinae extending the thoracic and lumbar spine.
Neck
Longus colli
Deep cervical flexor; stabilizes and flexes the cervical spine.
Back
Lower trapezius
Depresses and upwardly rotates the scapula; key for healthy overhead motion.
Head
Masseter
Primary cause of jaw pain, ear pain and bruxism-related headache — the strongest muscle of mastication per gram.
Head
Medial pterygoid
Inner jaw elevator; protrudes and laterally shifts the mandible.
Shoulder
Middle deltoid
Powerful abductor of the shoulder past 15°.
Back
Middle trapezius
Retracts the scapula; stabilizes the shoulder blade during arm use.
Back
Multifidus
Deep spinal stabilizer at every segmental level; key for low back resilience.
Hip
Obturator internus
Deep hip external rotator; influences pelvic floor.
Head
Occipitalis
Posterior belly of the occipitofrontalis; tenses the scalp and refers pain into the head.
Hip
Pectineus
Adducts and flexes the hip.
Shoulder
Pectoralis major
Adducts, flexes and internally rotates the shoulder.
Shoulder
Pectoralis minor
Tilts the scapula anteriorly and depresses it; contributes to thoracic outlet symptoms.
Leg
Peroneus brevis
Everts and plantarflexes the foot.
Leg
Peroneus longus
Plantarflexes and everts the ankle.
Hip
Piriformis
A common mimic of true sciatica — buttock pain radiating down the leg, sometimes with neural symptoms.
Leg
Popliteus
'Unlocks' the knee from full extension; rotates the tibia internally.
Shoulder
Posterior deltoid
Extends and externally rotates the shoulder.
Shoulder
Pronator teres
Pronates the forearm; weak elbow flexor.
Hip
Quadratus femoris
Deep external rotator and adductor of the hip.
Back
Quadratus lumborum
One of the most common muscular sources of low back pain — deep, hard-to-localize pain that worsens with standing.
Foot
Quadratus plantae
Assists FDL in flexing the toes.
Back
Rectus abdominis
Flexes the trunk; stabilizes the pelvis.
Leg
Rectus femoris
Two-joint quadriceps: flexes the hip and extends the knee.
Back
Rhomboid major
Retracts and downwardly rotates the scapula.
Back
Rhomboid minor
Retracts the scapula together with rhomboid major.
Hip
Sartorius
Flexes, abducts and externally rotates the hip; flexes the knee.
Neck
Scalenes
Three deep neck muscles that refer pain into the chest, upper back, shoulder and down the arm — frequent mimics of cervical radiculopathy.
Leg
Semimembranosus
Deepest hamstring extending hip, flexing and internally rotating the knee.
Neck
Semispinalis capitis
Strong head extensor; rotates the head slightly.
Leg
Semitendinosus
Hamstring extending the hip and flexing the knee; rotates tibia internally.
Shoulder
Serratus anterior
Protracts and upwardly rotates the scapula; critical for overhead reach.
Back
Serratus posterior inferior
Depresses the lower ribs during expiration.
Back
Serratus posterior superior
Elevates the upper ribs during inspiration.
Leg
Soleus
Plantarflexes the ankle independent of knee position; key for running endurance.
Neck
Splenius capitis
Extends and rotates the head to the same side.
Neck
Splenius cervicis
Extends and rotates the neck to the same side.
Neck
Sternocleidomastoid (SCM)
The SCM refers pain to the forehead, eye, cheek and ear — a frequent and overlooked source of facial pain, headache and dizziness.
Shoulder
Subclavius
Depresses the clavicle and stabilizes the sternoclavicular joint.
Neck
Suboccipital muscles
Four small muscles between the occiput and upper cervical spine; fine-tune head position and proprioception.
Shoulder
Subscapularis
Largest rotator cuff muscle; powerful internal rotator and anterior glenohumeral stabilizer.
Shoulder
Supinator
Supinates the forearm; primary mover when the elbow is extended.
Shoulder
Supraspinatus
Source of deep shoulder pain that intensifies with abduction — often misread as pure rotator cuff tendinopathy.
Head
Temporalis
Fan-shaped jaw elevator over the temporal bone; closes and retracts the mandible.
Hip
Tensor fasciae latae
Flexes, abducts and internally rotates the hip; tensions the IT band.
Shoulder
Teres major
Adducts and internally rotates the shoulder; co-active with latissimus.
Shoulder
Teres minor
External rotator of the shoulder; member of the rotator cuff.
Leg
Tibialis anterior
Dorsiflexes and inverts the ankle.
Leg
Tibialis posterior
Plantarflexes and inverts the ankle; supports the medial arch.
Shoulder
Triceps brachii
Extends the elbow; long head extends the shoulder.
Neck
Upper trapezius
The upper fibers of the trapezius are one of the most common sources of tension headaches, neck stiffness and referred temple pain.
Leg
Vastus intermedius
Extends the knee; lies deep to rectus femoris.
Leg
Vastus lateralis
Extends the knee; largest of the quadriceps.
Leg
Vastus medialis
Extends the knee; oblique fibers (VMO) stabilize the patella medially.