Using the Muscle Charts: Students should be aware of all muscles listed in the charts below. You will be required to know the action for all muscles in the chart, as well as innervation for all but one of the muscles. You will also be asked to know origins and insertions of some of these muscles, based on the color-coding as described below. If a box is shaded in light blue on the muscle charts, you are expected to know this information for the exam, as written here. This includes all actions, and innervations (except for the grey box by the psoas), and some origins and insertions. We may ask you about any of the information in the blue boxes. For the boxes shaded in light green, we will not ask you about that specific origin or insertion on the exam. However, you should have an understanding of the location of the muscle, including the general area of that origin and insertion so that you can understand so that you can understand the action of that muscle. For example, understanding that a muscle inserts on the proximal phalanx rather than the distal phalanx tells you that it can only act on the metatarsophalangeal joint, not the interphalangeal joints of that toe. Understanding origin and insertion of muscles around the hip can help you understand why one muscle may internally rotate the hip but another may externally rotate the hip. If you don’t have a general understanding of origin and insertion, it is difficult to understand the action of a muscle. ***Some sources provide differing synergistic movements for some muscles. Therefore, your book may differ from this chart on some of these small movements. This is also true for the origins and insertions. You will only be tested on the actions, origins, and insertions provided in this chart. Gluteal Muscles Muscle Action(s) Origin Insertion Innervation Extends, laterally rotates, Iliotibial tract (to Gerdy’s tubercle) Inferior gluteal Gluteus Maximus Iliac crest, sacrum, coccyx and abducts the hip Gluteal tuberosity of femur nerve Gluteus Medius Abducts and medially Posterior iliac crest Superior Greater trochanter of femur Gluteus Minimus rotates hip Lateral ilium gluteal nerve Lateral Rotators of the Hip Muscle Action(s) Piriformis Quadratus Femoris Superior Gemellus Laterally rotate the hip Inferior Gemellus Obturator Internus Obturator Externus Posterior Thigh Muscles Muscle Action(s) Origin Insertion Innervation Long Head: extends hip Long head: Tibial division of sciatic nerve Long head: Ischial tuberosity Biceps Femoris Long & Short Head: flexes and Head of fibula Short head: Common fibular (peroneal) Short head: Linea aspera laterally rotates knee division of sciatic nerve Medial condyle Semimembranosus Extends hip and flexes knee; of tibia Ischial tuberosity Tibial division of sciatic nerve medially rotates knee Pes anserine Semitendinosus insertion Anterior Thigh Muscles Muscle Action(s) Origin Insertion Innervation Transverse processes of Psoas Major Lesser trochanter, Flex the hip lumbar vertebrae merge to form the Iliacus Iliac fossa Iliopsoas Hip: flexion, abduction & lateral rotation Anterior superior iliac spine Sartorius Pes anserine insertion Knee: flexion & medial rotation (ASIS) Anterior inferior iliac spine Rectus Femoris Hip: flexion Knee: extension (AIIS) Femoral Vastus Quadriceps tendon to nerve Quadriceps Anterolateral femur Intermedius patella and then Muscle Greater trochanter, gluteal patellar ligament to Group Vastus Lateralis Extends knee tuberosity, linea aspera tibial tuberosity Vastus Medialis Linea aspera Medial Thigh Muscles Muscle Action(s) Origin Insertion Innervation Hip: Adduction, medial rotation Gracilis Pes anserine insertion Knee: Flexion, medial rotation Inferior ramus of pubis Adductor Brevis Obturator nerve Linea aspera of femur Adductor Longus Adducts, medially rotates, and Pubic tubercle flexes hip Pectineal line of Femoral nerve & obturator Pectineus Pectineal line of femur pubis nerve Adductor part: Adducts, medially Adductor part: Obturator Inferior ramus of rotates, and flexes hip Linea aspera nerve Adductor Magnus pubis Hamstring part: extends and Adductor tubercle Hamstring part: Tibial Ischial tuberosity laterally rotates hip division of sciatic nerve Lateral Thigh Muscle Muscle Action(s) Origin Insertion Innervation Tensor Fasciae Flexes, abducts and Iliac crest posterior to anterior Iliotibial tract (IT band, to Gerdy’s Superior gluteal nerve Latae medially rotates hip superior iliac spine (ASIS) tubercle) Leg: Anterior Compartment Muscles Muscle Action(s) Origin Insertion Innervation Extends MTP, PIP, & DIP Extensor Digitorum Lateral condyle of tibia; anterior fibula; of toes 2–5, dorsiflexes & Distal phalanges of toes 2–5 Longus interosseous membrane everts ankle Extends MTP & IP of Distal phalanx of great (1st) Extensor Hallucis Longus great (1st) toe, dorsiflexes Anterior fibula Deep fibular toe & inverts ankle (peroneal) Fibularis (Peroneus) Dorsiflexes and weakly nerve Anterior distal fibula Base of 5th metatarsal Tertius everts ankle Dorsiflexes & inverts 1st Metatarsal & first (medial) Tibialis Anterior Lateral condyle and proximal tibia ankle cuneiform Leg: Superficial Posterior Compartment Muscles Muscle Action(s) Origin/Insertion Innervation Flexes knee; Posterior surfaces of femoral Gastrocnemius plantar flexes epicondyles ankle Calcaneus (via calcaneal [Achilles] tendon) Plantar flexes Head and proximal shaft of fibula; Soleus Tibial nerve ankle medial border of tibia Weak knee flexor Plantaris and weak ankle Lateral supracondylar ridge of femur Posterior calcaneus plantar flexor Leg: Deep Posterior Compartment Muscles Muscle Action(s) Origin Insertion Innervation Flexor Digitorum Plantar flexes and weakly inverts ankle; Posteromedial tibia Distal phalanges of toes 2–5 Longus flexes MTP, PIP. & DIP of toes 2–5 Flexor Hallucis Plantar flexes & weakly inverts ankle; flexes Posterior inferior fibula Distal phalanx of great (1st) toe Longus MTP & IP of great toe Tibial nerve Tibialis Posterior Plantar flexes & inverts ankle Fibula, tibia 2nd -5th Metatarsals, distal tarsals Medially rotates tibia to unlock knee; flexes Popliteus Lateral condyle of femur Posterior, proximal tibia knee Leg: Lateral Compartment Muscles Muscle Action(s) Origin Insertion Innervation Fibularis Head and superior portion of fibula, Base of 1st metatarsal, medial (Peroneus) Longus Everts ankle, assist lateral condyle of tibia cuneiform Superficial plantar flexion of fibular Fibularis ankle Mid-lateral fibula Base of 5th metatarsal (peroneal) nerve (Peroneus) Brevis Dorsal Surface of Foot Muscle Action(s) Origin Insertion Innervation Extensor Hallucis Brevis Extends MTP joint of great toe Proximal phalanx of great toe Deep fibular Calcaneus (peroneal) Extensor digitorum Brevis Extends MTP & both IP joints of toes 2–4 Middle phalanges of toes 2–4 nerve Plantar Surface of Foot Muscle Action(s) Origin Insertion Innervation Adductor Transverse head: 3rd-5th MP joints Proximal phalanx of Adducts great toe (MTP) Hallucis Oblique head: Bases 2nd-4th metatarsals great toe Flexor Digiti Proximal phalanx of Flexes MTP joint of toe 5 5th Metatarsal Minimi Brevis toe 5 Dorsal Proximal phalanges Abducts toes (MTP) Interossei toes 2–4 Adjacent sides of metatarsals Plantar Proximal phalanges Lateral plantar nerve Adducts toes (MTP) Interossei toes 3–5 Abductor Digiti Proximal phalanx of 5th Abducts 5th toe (MTP) Minimi toe Aligns flexor digitorum longus Quadratus Flexor digitorum tendons to aid flexion of toes Plantae longus tendons 2–5 (all joints) Flexor Calcaneus Flexes MTP and PIP joints of Middle phalanges of Digitorum toes 2–5 toes 2–5 Brevis Abductor Proximal phalanx of Abducts great toe (MTP) Medial plantar nerve Hallucis great toe Flexor Hallucis Proximal phalanx of Flexes MTP joint of great toe Cuboid & lateral (3rd) cuneiform Brevis great toe 1st: Medial plantar Flexes MTP joints & extends Extensor digitorum Lumbricals Flexor digitorum longus tendons nerve 2nd -4th:: lateral PIP & DIP joints of toes 2–5 longus tendons plantar nerve .