Lab Terms: Appendicular Muscles

Psoas Major

Round muscle adjacent to iliacus; flexes hip and rotates femur laterally; flexes vertebral column

Iliacus

Originates on the iliac fossa; flexes hip and rotates femur laterally, flexes vertebral column

Thoracolumbar Fascia

Aponeuroses of oblique muscles of the posterior abdominal wall

Iliopsoas

Composed of two muscles as they join at the inguinal ligament

Pectineus

Small muscle medial to the iliopsoas; adducts and flexes femur

Sartorius

Runs diagonally across anterior side of thigh from the ilium to the medial surface of tibia; abducts femur and rotates leg laterally

-Origin: Anterior superior iliac spine

-Insertion: Proximal surface of tibia

-Action: Flexes and laterally rotates hip; flexes knee

Tensor Fasciae Latae

Muscle located on the superior, lateral aspect of the thigh; abducts femur

Iliotibial Tract

Fibrous band extending from the iliac crest and gluteus maximus muscle, down the lateral thigh to the lateral condyle of the tibia

Quadriceps Femoris

Composed of four muscles

Vastus Lateralis

Runs vertically on lateral side of thigh; extends lower leg

Vastus Intermedius

Directly beneath the rectus femoris; extends lower leg

Rectus Femoris

Runs vertically on anterior side of thigh; extends lower leg

Vastus Medialis

Runs vertically on medial side of thigh; extends lower leg

Gracilis

Runs vertically from pubis along medial side of the thigh to the tibia; adducts thigh, flexes and rotates lower leg

-Origin: Ischiopubic Ramus

-Insertion: Proximal surface of tibia

-Action: Adducts hip; flexes knee

Adductor Longus

Most superficial adductor on medial side of thigh; adducts, flexes, and externally rotates lower leg

Adductor Brevis

Small adductor between longus and magnus; adducts, flexes, and externally rotates lower leg

Adductor Magnus

Largest adductor on medial side of thigh; adducts, flexes, and externally rotates lower leg

Hamstrings

Muscles on posterior side of thigh

Semimembranosus

Most medial of hamstrings; flexes lower leg, extends and medially rotates leg

Semitendinosus

Between the semimembranosus and biceps femoris; flexes lower leg, extends and medially rotates thigh

-Origin: Ischial tuberosity

-Insertion: Proximal surface of tibia

-Action: Flexes knee, extends hip

Biceps Femoris

Two-headed muscle, most lateral; flexes lower leg, extends thigh and rotates it laterally

Biceps Femoris (2nd Head)

Two-headed muscle, most lateral; flexes lower leg, extends thigh and rotates it laterally

Medial Meniscus

C-shaped fibrocartilage located between the medial condyles that provides cushion within the knee joint

Lateral Meniscus

C-shaped fibrocartilage located between the lateral condyles that provides cushion within the knee joint

Anterior Cruciate Ligament

Ligament connecting the posterior side of the femur to the anterior surface of the tibia, preventing anterior sliding of the tibia

Posterior Cruciate Ligament

Ligament connecting the anterior side of the femur to the posterior surface of the tibia, preventing posterior sliding of the tibia

Fibular (Lateral) Collateral Ligament

Ligament located on the lateral surface of the knee joint, providing stability and preventing hyperadduction of the leg at the knee

Tibial (Medial) Collateral Ligament

Ligament located on the medial surface of the knee joint, providing stability and preventing hyperabduction of the leg at the knee

Gastrocnemius

Calf muscle; flexes foot and knee

-Origin: Lateral and medial condyles of the femur

-Insertion: Calcaneal tuberosity via calcaneal (Achilles) tendon

-Action: Flexes knee; plantar flexes foot

Soleus

Beneath the gastrocnemius; plantar flexes foot

Plantaris

Small muscle on posterior side of knee; flexes foot and knee

Popliteus

Deep muscle in the posterior region of the knee; flexes and rotates leg

Calcaneal Tendon

Tendon that connects gastrocnemius and soleus to calcaneus

Flexor Digitorum Longus

Originates on posterior surface of tibia; inserts on phalanges; flexes digits

Tibialis Posterior

Originates on tibia and fibula; inserts on metatarsals; inversion and plantar flexion of foot

Flexor Hallucis Longus

Originates on posterior side of fibula; inserts on hallux; flexes hallux

-Origin: Posterior surface of fibula

-Insertion: First digit

-Action: Flexes first digit

Tibialis Anterior

Originates on lateral condyle of tibia; inserts on first metatarsal; dorsiflexes and inverts foot

-Origin: Lateral surface of tibia

-Insertion: Medial cuneiform and first metatarsal

-Action: Dorsiflexes and inverts foot

Extensor Hallucis Longus

Originates on fibula; inserts on distal phalanx of hallux; extends hallux

Extensor Digitorum Longus

Originates on tibia and fibula; inserts on digits 2-5 (has 4 tendons); extends and dorsiflexes digits/foot

Extensor Hallucis Brevis

Muscle on top of the foot; originates on the calcaneus; inserts on the hallux; helps to extend the hallux

Extensor Digitorum Brevis

Four-part muscle deep to the tendons of the extensor digitorum longus; originates on the calcaneus; inserts on digits 2-5; helps extend digits 2-5

Fibularis Longus

Originates on tibia and fibula; inserts on first metatarsal; flexes and everts foot

-Origin: Lateral surface of fibula

-Insertion: Medial cuneiform and first metatarsal

-Action: Plantar flexes and everts foot

Fibularis Longus (Lateral Aspect)

Originates on tibia and fibula; inserts on first metatarsal; flexes and everts foot

-Origin: Lateral surface of fibula

-Insertion: Medial cuneiform and first metatarsal

-Action: Plantar flexes and everts foot

Fibularis Brevis

Originates on distal part of fibula; inserts on fifth metatarsal; flexes and everts foot - muscle in medial distal end of tibia that extends to the foot

Fibularis Tertius

Originates on anterior surface of fibula; inserts on fifth metatarsal; flexes and everts foot

Gluteus maximus

Largest and most superficial gluteal muscle; extends thigh

Gluteus Medius

Middle gluteal muscle; abducts and rotates thigh medially

-Origin: Gluteal surface

-Insertion: Greater trochanter

-Action: Abducts hip; medially and laterally rotates hip

Gluteus Minimus

Deepest gluteal muscle; abducts thigh

Piriformis

Pyrimidal muscle inferior to gluteus medius; rotates thigh laterally

Superior Gemellus

Inferior to the piriformis; runs from the ischial spine to the greater trochanter

Inferior Gemellus

Inferior to the obturator internus; runs from the ischial tuberosity to the greater trochanter; aids in lateral rotation of the hip

Obturator Internus

Located inferior to the superior gemellus and aids in lateral rotation of the hip

Obturator Externus

Deep to the quadratus femoris; aids in lateral hip rotation

Quadratus Femoris

Most inferior of the deep hip rotators

Trapezius (posterior aspect)

Large V-shaped muscle on upper back

-Origin: External occipital protuberance; superior nuchal line; spinous processes of C7-T12

-Insertion: Clavicle; acromion process; spine of scapula

-Action: Rotates, retracts, elevates, and depresses scapula, extends neck

Trapezius (Lateral Aspect)

Large V-shaped muscle on upper back

-Origin: External occipital protuberance; superior nuchal line; spinous processes of C7-T12

-Insertion: Clavicle; acromion process; spine of scapula

-Action: Rotates, retracts, elevates, and depresses scapula, extends neck

Trapezius (Anterior Aspect)

Large V-shaped muscle on upper back

-Origin: External occipital protuberance; superior nuchal line; spinous processes of C7-T12

-Insertion: Clavicle; acromion process; spine of scapula

-Action: Rotates, retracts, elevates, and depresses scapula, extends neck

Deltoid

Triangular shoulder muscle; major abductor of humerus

-Origin: Clavicle, acromion process, and spine of scapula

-Insertion: Deltoid tuberosity

-Action: Flexes, extends, and abducts shoulder joint

Levator Scapulae

Inserts on medial border and superior angle of scapula; adducts scapula

Levator Scapulae (Lateral Aspect)

Inserts on medial border and superior angle of scapula; adducts scapula

Rhomboid Major

Rectangular muscle on upper back; elevates and retracts scapula

Rhomboid Minor

Superior to rhomboid major; elevates and retracts scapula

Supraspinatus

Extends from the supraspinous fossa to humerus; abducts humerus

Infraspinatus

Originates on the infraspinous fossa; rotates humerus laterally

Teres Major

Extends from lateral border of the scapula to the lesser tubercle of the humerus; medially rotates the arm

Teres Major (Anterior Aspect)

Extends from lateral border of the scapula to the lesser tubercle of the humerus; medially rotates the arm

Teres Minor

Originates on the lateral border of the scapula, inserts on humerus; extends and rotates humerus laterally

Subscapularis

Originates on subscapular fossa; major medial rotator of arm

Serratus Anterior

Extends from upper posterior ribs towards medial border of scapula; draws scapula towards rib cage

Latissimus Dorsi

Originates on the lower ribs and inserts on the humerus; medially rotates humerus; helps with forces inhalation when upper limb is fixed

Latissimus Dorsi (Anterior Aspect)

Originates on the lower ribs and inserts on the humerus; medially rotates humerus; helps with forced inhalation when upper limb is fixed

Pectoralis Major

Major chest muscle; adducts humerus medially; helps with forced inhalation when upper limb is fixed

Pectoralis Minor

Small chest muscle deep to the pectoralis major; acts on scapula; helps with forced inhalation when upper limb is fixed

Coracobrachialis

Small muscle in armpit region; flexes and adducts humerus synergistically with pectoralis major

Brachialis

Between triceps and biceps; flexes forearm

Brachialis (Insertion)

Between triceps and biceps; flexes forearm

Biceps Brachii

Two-headed muscle on the anterior side of the upper arm; elbow flexor and forearm supinator

-Origin: Supraglenoid tubercle and coracoid process

-Insertion: Radial tuberosity

-Action: flexes elbow and shoulder; supinates forearm

Triceps Brachii

Three-headed muscle on the posterior side of the upper arm; extends forearm

-Origin: Infraglenoid tubercle and posterior shaft of humerus

-Insertion: Olecranon process

-Action: Extends elbow and shoulder

Brachioradialis

Originates on the lateral supracondylar ridge of humerus; inserts on the styloid process of the radius; flexes forearm

Extensor Carpi Radialis Longus

Originates on lateral ridge of humerus; inserts on second metacarpal; abducts the hand

Extensor Carpi Radialis Brevis

Originates on lateral epicondyle, inserts on third metacarpal; abducts the hand

Abductor Pollicis Longus

Originates on radius and ulna; inserts on first metacarpal; abducts thumb

Extensor Pollicis Brevis

Originates from the dorsal surface of the radius; extends the first phalanx of the thumb and abducts the hand

Extensor Pollicis Longus

Originates dorsolaterally from the middle part of the ulna; extends the second phalanx of the thumb and abducts the hand

Extensor Digitorum

Originates on lateral humeral epicondyle, inserts on digits; extends fingers

-Origin: Lateral epicondyle of humerus

-Insertion: Digits 2-5

-Action: Extends digits 2-5

Extensor Digiti Minimi

Slender muscle on the ulnar side of the extensor digitorum, originates on the lateral epicondyle of the humerus; extends proximal phalanx of little finger

Extensor Indicis

Narrow muscle medial to and parallel with the extensor pollicis longus, originates on the posterior surface of the ulna; inserts on the tendon of the extensor digitorum of the index finger; extends distal and middle phalanges

Extensor Carpi Ulnaris

Originates on the olecranon process of ulna; inserts on fifth metacarpal; adducts wrist

Anconeus

Short, triangular elbow muscle on posterior side; extends elbow joint and abducts ulna during pronation

Flexor Digitorum Profundus

Originates on proximal two-thirds of ulna; inserts on four distal phalanges; flexes wrist and digits

Flexor Carpi Ulnaris

Originates on the humerus and ulna; inserts on carpals and metacarpals; flexes wrist with power

Palmaris Longus

Originates on medial humeral epicondyle; inserts on palmar aponeurosis; flexes wrist weakly

Flexor Digitorum Superficialis

Originates on humerus, ulna, and radius; inserts on middle phalanges of four digits; flexes wrist, hand, and digits

-Origin: Medial epicondyle of the humerus

-Insertion: Digits 2-5

-Action: Flexes digits 2-5

Flexor Carpi Radialis

Originates on humerus; inserts on metacarpals; flexes wrist and abducts hand

Supinator

Two heads, one originates on ulna and the other on the humerus; inserts laterally on radius; supinates forearm/hand

Supinator (Anterior Aspect)

Two heads, one originates on ulna and the other on the humerus; inserts laterally on radius; supinates forearm/hand

Pronator Teres

Originates on humerus; inserts on radius; pronates forearm/hand

Flexor Pollicis Longus

Originates on radius and ulna; inserts on thumb; flexes thumb distally

Pronator Quadratus

Originates on ulna; inserts on radius; pronates forearm/hand

Thenar Muscles

Group of muscles in the lateral portion of the palm including flexor pollicis brevis, abductor pollicis brevis, and opponens pollicis