Muscles MD3 Flashcards by Trent Tamate

Deltoid

origin: lateral 1/3 of clavicle, acromion, spine of scapula
insertion: deltoid tuberosity
innervation: axillary nn. (C5, C6)

action:

anterior deltoid: humeral flexion & internal rotation

lateral/middle deltoid: humeral abduction

posterior deltoid: humeral extension & external rotation

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Teres Major

origin: posterior surface of inferior angle of scapula
insertion: medial lip of intertubercular/bicipital groove
innervation: lower subscapular nn (C5, C6)
action: adduction & internal rotation of humerus

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Teres Minor

origin: mid part of lateral border of scapula
insertion: inferior facet of greater tubercle of humerus
innervation: axillary nn (C5, C6)

actions:

controls internal rotation of humerus (functional action)

external rotation of humerus

*part of rotator cuff (provide dynamic stability via eccentric contraction for shoulder stabilization/re-enforcement of GH joint capsule)

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Infraspinatus

origin: infraspinous/infraspinatus fossa of scapula
insertion: middle facet of greater tubercle of humerus
innervation: suprascapular nn (C5, C6)

actions:

controls IR of humerus (functional action)

ER of humerus

*part of rotator cuff (provide dynamic stability via eccentric contraction for shoulder stabilization/re-enforcement of GH joint capsule)

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Supraspinatus

origin: supraspinous/supraspinatus fossa of scapula
insertion: superior facet of greater tubercle of humerus
innervation: suprascapular nn (C5, C6)

actions:

prevent superior translation of humeral head during abduction (protect supraspinatus, bursae, etc. from getting pinched by humeral head & acromion) (functional action)

initiate abduction & assist deltoid in abduction of humerus

*part of rotator cuff (provide dynamic stability via eccentric contraction for shoulder stabilization/re-enforcement of GH joint capsule)

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Subscapularis

origin: subscapular fossa of scapula (anterior)
insertion: lesser tubercle of humerus
innervation: upper & lower subscapular nn (C5-C7)

actions:

control ER of humerus (functional action)

IR & adduction of humerus

*part of rotator cuff (provide dynamic stability via eccentric contraction for shoulder stabilization/re-enforcement of GH joint capsule)

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Pectoralis Minor

origin: ribs 3-5 (highly variable)
insertion: coracoid process of scapula
innervation: medial pectoral nn (C8, T1)

actions:

stabilizes shoulder, draws scapula anterior & depresses it inferiorly towards the thorax (helps upper extremity reach out forward)

divides axillary aa into its 3 parts

(1st part medial to pec minor, 2nd part posterior, 3rd part lateral)

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Serratus Anterior

origin: lateral aspects of ribs 1-8

insertion:

upper 4 heads- anterior surface of medial border of scapula,

lower 4- inferior angle of scapula

innervation: long thoracic nn (C5-C7)

actions:

protraction of scapula, holds medial border against thoracic wall, upward rotation/external rotation

long thoracic nn can be damaged during mastectomy (winged scapula), unable to raise arm above horizontal

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Pectoralis Major

origin:

clavicular- ant, medial 1/2 of clavicle

sternal- ant sternum, 1st 6 costal cartilages, external oblique aponeurosis

insertion: lateral lip of intertubercular/bicipital groove
innervation: lateral & medial pectoral nn (clavicle C5, C6, sternum C7-T1)

actions:

adduction & IR of humerus, draws scapula anterior & inferior

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Triceps brachii

origin:

long head- infraglenoid tubercle of scapula

lateral head- posterior humerus, superior to spiral groove (radial groove)

medial head- posterior humerus, inferior to spiral groove (radial groove)

insertion: olecranon process of ulna
innervation: radial nn (C6-C8)
actions: extension at elbow

heads recruited additively as needed, medial first (workhorse), lateral (strongest), long (last)

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Latissimus Dorsi

origin: spinous processes of T7-L5, inferior angle of scapula, thoracolumbar fascia, iliac crest of sacrum, inferior 3 or 4 ribs
insertion: floor of intertubercular/bicipital groove of humerus
innervation: thoracodorsal nn (C6-C8)
actions: adduction, IR & extension of the humerus

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Biceps brachii

brachial aa, musculocutaneous nn (C5, C6)

Long head

origin: supraglenoid tubercle, thru glenoid labrum (constant tension causes slap lesions)

Short head

origin: coracoid process
insertion: radial tuberosity (medial radius) & bicipital aponeurosis
action: primary supinator of forearm, also resistive elbow flexion (hand position dependent)

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Coracobrachialis

brachial aa, musculocutaneous nn (C5-C7)

origin: coracoid process
insertion: mid 1/3 of medial humerus
actions: humeral adduction, flexion @ GH joint (shoulder)
- musculocutaneous nn pierces it

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Brachialis

radial recurrent aa, musculocutaneous nn (C5, C6)

origin: anterior humerus
insertion: coronoid process & tuberosity of ulna
actions: primary elbow flexor (active throughout elbow flexion)
- musculocutaneous nn runs between biceps brachii & brachialis

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Brachioradialis

radial recurrent aa, radial nn (C5, C6)

origin: lateral supracondylar ridge of humerus
insertion: radial styloid process (distal radius)
actions: elbow flexion

only flexor in the posterior compartment, superficial layer

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Pronator teres

ulnar & radial aa, median nn (C6, C7)

origin: medial epicondyle of humerus & coronoid process of ulna
insertion: lateral aspect of mid radius
actions: pronation of forearm, elbow flexion
- superficial anterior compartment

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Flexor Carpi Radialis

radial aa, median nn (C6, C7)

origin: medial epicondyle of humerus
insertion: base of 2nd & 3rd metacarpals
actions: flexion & abduction of wrist
- superficial anterior compartment

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Flexor Carpi Ulnaris

ulnar aa, ulnar nn (C8, T1)

origin: medial epicondyle of humerus
insertion: pisiform, hook of hamate, base of 5th metacarpal
actions: flexion and adduction of wrist
- anterior superficial compartment

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Palmaris Longus

ulnar aa, median nn (C7, C8)

origin: medial epicondyle of humerus
insertion: flexor retinaculum & palmar aponeurosis
actions: wrist flexion, tenses palmar aponeurosis
- anterior superficial compartment

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Abductor Pollicis Longus

origin: proximal ulna, radius, interosseus membrane
insertion: base of 1st metacarpal
action: abduction & extension of thumb
innervation: radial nn (deep radial nn) (C7, C8)

*deep layer on posterior forearm

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Flexor Digitorum Superficialis

origin: anterior oblique line of radius, coronoid process of ulna, medial epicondyle of humerus
insertion: middle phalanges
innervation: median nn (C7, C8, T1)
action: flexion of middle phalanges @ PIP, then flexion of proximal phalanges @ MCP

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Flexor Digitorum Profundus

origin: ulna & interosseus membrane
insertion: distal phalanges (2-5)
innervation: median nn & ulnar nn (4th & 5th digits)
action: flexion of distal phalanges @ DIP

*deep anterior forearm

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Flexor Pollicis Longus

origin: radius
insertion: distal phalanx of thumb
innervation: median nn
action: flexion of thumb

*deep anterior forearm

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Pronator Quadratus

origin: ulna
insertion: radius
innervation: median nn
action: pronation of forearm

*deep anterior forearm

square “quad” shaped muscle

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Abductor pollicis brevis

origin: flexor retinaculum, scaphoid, trapezium insertion: lateral proximal phalanx of thumb innervation: median nn action: abduction of thumb \*thenar (palmar base of thumb) -intrinsic muscle

Flexor Pollicis Brevis

origin: flexor retinaculum, scaphoid, trapezium insertion: proximal phalanx of thumb innervation: median nn action: flexion of thumb @ MCP joint \*thenar, intrinsic

Opponens Pollicis

origin : flexor retinaculum, scaphoid, trapezium insertion: lateral 1st metacarpal innervation: median nn action: opposition of thumb \*thenar, intrinsic \*deep to flexor and abductor pollicis brevis

Adductor Pollicis

-ulnar nn.

Abductor Digiti Minimi

origin: pisiform insertion: medial 5th proximal phalanx innervation: ulnar nn action: abduction of 5th digit, aids in flexion of proximal 5th phalanx \*hypothenar (muscles on medial side of palm, pinky)

Flexor Digiti Minimi

origin: hook of hamate & flexor retinaculum insertion: medial 5th proximal phalanx innervation: ulnar nn. action: flexion of 5th proximal phalanx \*hypothenar

Opponens digiti minimi

origin: hook of hamate & flexor retinaculum insertion: medial border of 5th metacarpal innervation: ulnar nn. action: opposition of 5th digit/pinky \*hypothenar \*deep to flexor & abductor digiti minimi

Extensor Pollicis Longus

origin: posterior middle 1/3 of ulna insertion: distal phalanx of thumb innervation: radial nn. action: extension of thumb (IP, MCP, CMC jts) \*deep posterior forearm

Extensor Pollicis Brevis

origin: posterior distal 1/3 of radius insertion: proximal phalanx of thumb innervation: radial nn. action: extension of thumb @ MCP & CMC \*deep muscle of forearm (extrinsic)

Extensor Carpi Radialis Longus

origin: lateral supraepicondylar ridge of humerus insertion: posterior base of 2nd metacarpal innervation: radial nn. action: flexion & abduction of wrist, active during fist clenching \*medial to brachioradialis

Extensor Carpi Radialis Brevis

origin: lateral epicondyle of humerus (common extensor tendon) insertion: posterior base of 3rd metacarpal innervation: radial nn action: extension & abduction @ wrist

Extensor Digitorum

origin: lateral epicondyle of humerus (common extensor tendon) insertion: distal phalanges 2-5 (via extensor expansions) innervation: radial nn. action: extension of wrist & digits 2-5 primarily @ MCP joint

Extensor Indicis

origin: posterior distal 1/3 of ulna insertion: extensor hood of 2nd digit innervation: radial nn. action: independent extension of 2nd digit \*deep posterior forearm

Supinator

origin: lateral epicondyle of humerus, ulna, radial collateral & annular ligaments insertion: lateral, posterior & anterior proximal radius innervation: radial nn. action: supination of forearm \*deep posterior forearm

Lumbricals

origin: lateral 2: lateral side of FDP tendons of 2 & 3rd digits medial 2: FDP tendons of 3-5th digits insertion: lateral extensor expansions innervation: lateral 2: median nn. medial 2: ulnar nn. action: flexion @ MCP, extension @ IP joints

Interosseus Muscles

DAB (dorsal) & PAD (palmar) innervation: ulnar nn.

Extensor Hood

tendonous aponeurosis of 2-5th digits flatten and wrap around distal metacarpals & proximal phalanges forming a dorsal hood that holds extensor tendons in place

Pectineus

O/I: superior pubic ramus -\> pectineal line of humerus innervation: Femoral nn. Actions: adduction & flexion of thigh, internal rotation of humerus

Iliopsoas

psoas major + iliacus (join @ midpoint) O/I: lumbar vertebrae, iliac crest-\> lesser trochanter of femur innervation: lumbar rami (L1-3), femoral nn. actions: flexion of thigh, trunk flexion when legs grounded, maintains lordosis of lumbar spine (tightness of muscle = incr lordosis)

Sartorius

longest muscle in body, spans two joints (hip & knee) O/I: anterior superior iliac spine- \> pes anserine innervation: femoral nn. actions: "tailor's muscle", **flexion of thigh/hip**, **flexion of knee**, weak **ext rotation of thigh**, weak **abduction of thigh**, primarily synergistic

Quadriceps Femoris

Rectus Femoris: O: anterior inferior iliac spine -spans two joints (hip & knee), longest muscle in quadriceps femoris, "kicking muscle" Vastus Lateralis: O: greater trochanter of femur, lateral lip of linea aspera Vastus Intermedius: O: anterolateral shaft of femur Vastus Medialis: O: intertrochanteric line & medial lip of linea aspera of femur All come together to insert on **quadriceps tendon**-\> patella-\> patellar ligament to attach onto tibial tuberosity Should be 3:2 stronger than hamstring, commonly 3 x stronger Actions: flexion of hip/thigh (only rectus femoris), extension of knee (all) Innervation: femoral nn.

Adductor Brevis, Adductor Longus, Adductor Magnus

O/I: inferior ischial & pubic ramus-\> linea aspera & adductor tubercle of femur (adductor magnus, hamstring part) innervation: obturator nn. (all), magnus = obturator nn. (adductor part), tibial nn. (hamstring part) actions: adduct thigh (brevis, longus, adductor part of magnus), may flex thigh (brevis), ext thigh (hamstring part of magnus) \*obturator nn splits ant/post @ brevis magnus is most powerful adductor adductor hiatus (magnus) allows transmission of femoral aa & vv from adductor canal to popliteal fossa

Gracilis

O/I: inferior pubic ramus-\> pes anserine innervation: obturator nn. actions: adduction of thigh, flexion of knee, internal rotation of humerus when knee flexed

Obturator Externus

O/I: obturator membrane in obturator foramen-\> trochanteric fossa on greater trochanter of humerus innervation: obturator nn. actions: external rotation of thigh, stabilizes femoral head in acetabulum

Gluteus maximus

-largest and most superficial (superficial gluteal, primary movers of hip) O/I; iliac crest, sacrum, coccyx -\> iliotibial (IT) band, some fibers to gluteal tuberosity of femur innervation: inferior gluteal nn actions: mainly hip extension (esp. up inclines) & external rotation of femur

Gluteus Medius & Minimus

O/I: gluteal surface of ilium (beneath iliac crest, deep to gluteus maximus)-\> greater trochanter of femur innervation: superior gluteal nn. actions: abduction of thigh, internal rotation of femur, medius stabilizes pelvis during gait Trendelenburg sign/gait: weakness of these muscles

Tensor Fasciae Latae

O/I: anterior superior iliac spine -\> iliotibial band innervation: superior gluteal nn. actions: flexion @ hip, abduction and internal rotation of femur - fusiform muscle (wide in middle, narrow at ends)

Piriformis

O/I: Sacrum -\> greater trochanter of femur innervation: anterior rami of S1 & S2 actions: external rotation of extended thigh, abductor of flexed thigh - superior gluteal nn & vessels travel above piriformis - inferior gluteal nn. & vessels travel below piriformis, along w/ sciatic nn. - piriformis syndrome (sciatica)- irritation of sciatic nn by piriformis causes pain in butt radiating down leg (sciatic nn.)

Triceps Coxae

Obturator Internus: O/I: ischiopubic ramus & obturator membrane -\> medial part of greater trochanter of femur innervation: nn to obturator internus (L5, S1) actions: **external rotation** of extnded thigh, abduction of flexed thigh \*located b/w superior & inferior gemelli Gemelli: O/I: ischial spine (superior) & ischial tuberosity (inferior) -\> medial part of greater trochanter of femur (all 3 tendons of triceps coxae join and insert onto the medial greater trochanter) innervation: nn to obturator internus (superior), nn. to quadratus femoris (inferior) (L5, S1) actions: **external rotation** of thigh

Quadratus Femoris

O/I: ischial tuberosity -\> intertrochanteric crest innervation: nn. to quadratus femoris (L5, S1) actions: strong external rotation of thigh - located inferior to inferior gemellus

Semitendinosus, Semimembranosus (part of hamstring)

O/I: ischial tuberosity -\> pes anserine (semitendinosus), posterior medial condyle of tibia, popliteal fossa, popliteal ligament (semimembranosus) innervation: tibial branch of sciatic nn. actions: extension of hip, flexion of knee, internal rotation w/ flexed knee - commonly used in ACL repair (semitendinosus)

Biceps Femoris (workhorse of the hamstring)

``` O/I: ischial tuberosity (long head), linea aspera & lateral supracondylar line of femur (short head) -\> fibular head, LCL of knee ``` innervation: tibial branch of sciatic (long head), common peroneal branch of sciatic (short head) actions: hip extension, knee flexion, external rotation of flexed knee \*hamstring strains are twice as likely as quads, commonly d/t co-contracture (e.g. running), avulsion at ischial tuberosity

Pes Anserine

- insertion of tendons from Sartorius, Gracilis, SemiTendinosus (Say Grace SomeTimes) onto anteriomedial upper tibia - looks like a goose's foot - common site of tendinitis/bursitis

Tibialis Anterior

O/I: upper 1/3 & lateral condyle of tibia -\> medial cuneiform & base of 1st metatarsal innervation: deep peroneal nn (branch off common peroneal) actions: dorsiflexion, inversion of ankle - on lateral surface of tibia, most superficial, strongest dorsiflexor

Extensor Digitorum Longus

O/I: lateral condyle of tibia & anterior shaft of fibula-\> middle and distal phalanges innervation: deep peroneal nn. actions: extension of 4 digits (not hallicus), dorsiflexion - most lateral anterior leg muscle, lies on medial side of fibula

Extensor Hallucis Longus

O/I: anterior interosseus membrane-\> distal 1st phalanx innervation: deep peroneal nn. actions: extension of great toe, dorsiflexion - deep muscle, lies between EDL & tibialis anterior

Peroneus (Fibularis) Tertius

O/I: distal anterior fibula-\> 5th metatarsal innervation: deep peroneal nn. actions: aids in dorsiflexion, eversion of foot, ankle proprioception

Peroneus Longus

O/I: upper lateral fibula-\> 1st metatarsal & medial cuneiform innervation: superficial peroneal nn. actions: plantar flexion & eversion of foot - posterior to lateral malleolus, underneath foot, thru groove in cuboid - antagonistic to peroneus tertius (plantar flexion) and agonistic (eversion) - longer, more superficial, originates higher up on tibia vs brevis

Peroneus Brevis

O/I: lower lateral fibula-\> lateral base of 5th metatarsal innervation: superficial peroneal nn. actions: eversion of foot, plantar flexion - deep to peroneus longus, runs posterior to lateral malleolus - common avulsion site (Jones fx)

Gastrocnemius

O/I: posterior condyles of femur-\> achilles tendon innervation: tibial nn. actions: plantar flexion (propulsion phase of walking), knee flexion - medial & lateral heads, fast-twitch muscle

Soleus

- deep to gastrocnemius, joins it distally to become achilles tendon (most powerful tendon) - workhorse of plantar flexion, (active in standing and postural balance) - popliteal aa & tibial nn lay underneath it innervation: tibial nn

Plantaris

O/I: lateral supracondylar ridge of femur-\> achilles innervation: tibial nn actions: weak plantar flexion, may be more significant in proprioception - absent in 5-10%, used for grafting to hand tendons

Popliteus

O/I: lateral femoral condyle-\> proximal posterior tibia innervation: tibial nn. actions: knee flexion, opposite screw home mechanism (turns femur laterally) - inferior floor of popliteal fossa

Flexor Hallucis Longus

O/I: posterior mid fibula-\> distal 1st phalanx innervation: tibial nn. actions: powerful great toe flexor, supports medial longitudinal arch of foot - runs under flexor digitorum longus tendon under navicular bone

Flexor Digitorum Longus

O/I: posterior tibia-\> distal lateral 4 phalanges innervation: tibial nn. actions: flexion of phalanges, plantar flexion, supports longitudinal arches - passes over tibialis posterior @ distal tibia

Posterior Tibialis

deepest/most anterior muscle in posterior compartment innervation: tibial nn. actions: works w/ tibialis anterior to invert foot, supports medial longitudinal arch - inserts on navicular and cuneiform bones - b/w flexor digitorum longus & flexor hallucis longus

1st layer of plantar muscles

**Abductor Hallucis** O/I: calcaneus-\> medial 1st proximal phalanx innervation: medial plantar nn. actions: abduction & flexion of great toe **Flexor Digitorum Brevis** O/I: calcaneus-\> both sides of middle phalanges 2-5 innervation: medial plantar nn. actions: flexion of digits 2-5 **Abductor Digiti Minimi** O/I: calcaneus-\> lateral 5th proximal phalanx innervation: lateral plantar nn. actions: abduction & flexion of 5th digit

2nd layer of plantar muscles

**Quadratus Plantae** O/I: calcaneus-\> posterolateral flexor digitorum longus tendon innervation: lateral plantar nn actions: assists FDL in flexion of digits 2-5, keeps FDL stable when lumbricals pull on it during flexion **Lumbricals** O/I: FDL tendon to medial aspect of digits 2-5 innervation: lumbrical #1 = medial plantar nn, #2-4 = lateral plantar nn actions: flexion of proximal phalanges, extension of middle & distal phalanges of digits 2-5

3rd layer of plantar muscles

**Flexor Hallucis Brevis** O/I: cuboid & lateral cuneiform-\> base of 1st proximal phalanx innervation: medial plantar nn actions: flexion of great toe **Adductor Hallucis** (oblique & transverse heads) O/I: Plantar ligaments of MTP joints (oblique), base of metatarsals 2-4 (transverse)-\> lateral aspect of 1st proximal phalanx innervation: lateral plantar nn. actions: stabilizes transverse arch by bringin metatarsals medially **Flexor Digiti Minimi** O/I: base of 5th metatarsal-\> proximal 5th phalanx innervation: lateral plantar nn. actions: flexion of 5th proximal phalanx

4th layer of plantar muscles

**Plantar Interossei (3 muscles, PAD)** innervation: lateral plantar nn. actions: adduction of digits 2-4 **Dorsal Interossei (4 muscles, DAB)** innervation: lateral plantar nn. actions: abduction of digits 2-4 \*both involved in flexion @ MTP \*2nd toe is midline in the foot (cannot abduct)

Extensor Digitorum Brevis, Extensor Hallucis Brevis (dorsal foot muscles)

innervation: deep peroneal nn. actions: aids 'long' counterparts in extension of digits 2-4 (EDB), 1st toe (EHB)

SGT FOS

Sartorius- Femoral nn Gracilis- Obturator nn semiTendinosis- Sciatic nn

Muscles MD3 Flashcards

(77 cards)