The

How Much Do We Need To Know On Muscles?”

Guide!

S Porter

Every year students ask me how much detail they need to know on muscles, the tables below give you the absolute minimum that you need to know to have a fighting chance of passing

Lower Limb Muscles

This is the least that you need to know for your exams, but if you learn more, then it will not be wasted.Muscle Origin Insertion Action

Gluteus maximus

outer surface of ilium, sacrum, coccyx, sacrotuberous ligament

75% iliotibial tract and 25% gluteal tuberosity of femur

extends & laterally rotates thigh; through iliotibial tract, it extends knee joint

Gluteus medius outer surface of ilium

greater trochanter

abducts thigh. Tilts pelvis when walking

Gluteus minimus outer surface of ilium

greater trochanter

abduct thigh; anterior fibers medially rotate thigh

Tensor fasciae latae

iliac crestiliotibial tract assists gluteus mx in locking

the knee into full extension

Piriformis lateral rotator of thigh

Superior gemellus

lateral rotator of thigh

Obturator internus

lateral rotator of thigh

Inferior gemellus lateral rotator of thigh

Pectineus lateral rotator of thigh

Obturator externus

lateral rotator of thigh

Sartoriusanterior superior iliac spine

upper medial surface of tibia

flexes, abducts, laterally rotates hip flexes knee – like looking at the sole of your own foot.

Iliacusiliac fossa

lesser trochanter

flexes thigh on trunk; if thigh is fixed, it flexes the trunk onto the thigh as in doing a sit up

Psoas 12th thoracic body; transverse

lesser trochanter along with

flexes thigh on trunk; if thigh fixed, it flexes trunk onto thigh as in doing a sit up

process, bodies & intervertebral discs of the 5 lumbar vertebrae

iliacus

Rectus femoris

straight head from anterior inferior iliac spine; reflected head from ilium above acetabulum

quadriceps tendon into patella; into tibial tuberosity by patellar tendon

extension of knee

Vastus lateralisupper end and shaft of femur

quadriceps tendon into patella; into tibial tuberosity by patellar tendon

extension of knee

Vastus medialisupper end and shaft of femur

into tibial tuberosity by patellar tendon

extension of knee

Vastus intermedius

shaft of femur

quadriceps tendon into patella; into tibial tuberosity by patellar tendon

extension of knee

Gracilisinferior ramus of pubis; ramus of ischium

upper part of shaft of tibia on medial surface

adducts thigh

Adductor longus body of pubis

posterior surface of shaft of femur

adducts thigh; assists in lateral rotation

Adductor brevis inferior ramus of pubis

posterior surface of shaft of femur

adducts thigh; assists in lateral rotation

Adductor magnus inferior ramus of pubis; ramus of ischium, ischial tuberosity

posterior surface of shaft of femur near linea aspera; adductor

adducts thigh and assists in lateral rotation; hamstring part extends thigh

tubercle of femur

Biceps femoris

long head ischial tuberosity; short head shaft of femur

head of fibulaflexes and laterally rotates leg; long head extends thigh

Semitendinosus ischial tuberosity

upper part medial surface of shaft of tibia

flexes and medially rotates leg; extends thigh

Semimembranosus

ischial tuberosity

medial condyle of tibia; forms oblique popliteal ligament

flexes and medially rotates leg; extends thigh

Tibialis anteriorshaft of tibia and interosseous membrane

medial cuneiform & base of first metatarsal

extends the foot; inverts foot at subtalar and transverse tarsal joints; supports medial longitudinal arch

Extensor digitorum

shaft of fibula and interosseous membrane

extensor expansion of lateral four toes extends toes; dorsiflexes

(extends) foot

Peroneus tertiusdorsiflexes (extends) foot; everts foot at subtalar and transverse tarsal joints

Extensor hallucis longus

shaft of fibula & interosseous membrane

base of distal phalanx of big toe

extends big toe; dorsiflexes (extends) foot; inverts foot at subtalar and transverse tarsal joints

Peroneus longus shaft of fibula

base of 1st metatarsal & medial cuneiform

plantar flexes foot; everts foot at subtalar & transverse tarsal joints; supports lateral longitudinal and transverse arches of foot

Peroneus brevis shaft of fibulabase of 5th metatarsal bone

plantar flexes foot; everts foot at subtalar & transverse tarsal joints; supports lateral longitudinal arch

Gastrocnemius medial and lateral

by way of Achilles

plantar flexes ankle, flexes knee

condyles of femur

tendon to calcaneum

Plantarislateral supracondylar ridge of femur

plantar flexes foot; flexes knee

Soleus shafts of tibia and fibula

by way of achilles tendon into calcaneum

powerful plantar flexor of ankle

Popliteuslateral condyle of femur

shaft of tibia

flexes knee, unlocks knee by laterally rotating femur on tibia

Flexor digitorum longus

shaft of tibia

distal phalanges of lateral four toes

flexes distal phalanges of lateral four toes; plantar flexes,supports medial and lateral longitudinal arches

Flexor hallucis longus

shaft of fibulabase of distal phalanx of big toe

flexes distal phalanx of big toe; plantar flexes foot; supports medial longitudinal arch

Tibialis posteriorshafts of tibia and fibula & interosseous membrane

tuberosity of navicular

plantar flexes foot; inverts foot at subtalar and transverse tarsal joints; supports medial longitudinal arch of foot

Extensor digitorum brevis

calcaneum

by four tendons into the proximal phalanx of big toe and long extensor tendons to 2nd, 3rd and 4th toes

extends toes,( looks like a bruise on top of the foot