Kinesiology Muscles:

Brachialis

Action: - true flexion of the elbow. - Pulls on the ulna, but does not rotate making this muscle the only pure flexor of this joint. Origin: - Distal half of the anterior shaft of the humerus Insertion: - Coronoid process of the ulna. Location: - Anteriorly Innervation: - Musculocutaneous nerve (C5,C6)

Flexor Hallucis Longus

*Action* - Flexion of the great toe at the metatarsophalangeal and interphalangeal joints (MTP, PIP, DIP) - Inversion of the foot - Plantar flexion of ankle *Application* - Pulling from the underside of the great toe, the flexor hallucis longus muscle may work independently of the flexor digitorum longus muscle or together with it. - These muscles are used effectively in walking if the toes are used in maintaining balance as each step is taken. - Walking with the toes rather than over them is an important action for them. *Origin*: - Middle two-thirds of the posterior surface of the fibula *Insertion*: - Base of the distal phalanx of the great toe, plantar surface *Innervation*: - Tibial nerve (L5, S1, S2) *Location*: - Posterior

Tibialis Anterior

*Action* - Dorsiflexion of ankle - Inversion of the foot *Application* - when this muscle contracts concentrically, it dorsiflexes the ankle and is used as an antagonist to the plantar flexors of the ankle. - *Strongly supports the medial longitudinal arch* in inversion; when walking on the outside of the foot or ice skating. *Origin*: - Upper two-thirds of the lateral surface of the tibia *Insertion*: ! Inner surface of the medial cuneiform and the base of the first metatarsal ! Location ! Anterior

Extensor Hallucis Longus

*Action* - Dorsiflexion of the ankle - Extension of the great toe at the metatarsophalangeal and interphalangeal joints (?MTP, PIP, DIP?) - weak Inversion of the foot *Application* - the four dorsiflexors of the foot -tibialis anterior, extensor digitorum longus, extensor hallucis longus and peroneus tertius may be exercised by walking on the heels with ankle flexed dorsally and the toes exteneded. *Origin*: - Middle two-thirds of the medial surface of the anterior fibula. *Insertion*: - Top of the base of the distal phalanx of the great toe. *Innervation*: - Deep peroneal nerve (L4, L5, S1) *Location*: - Anterior

Peroneus (fibularis) Longus

*Action* - Eversion of the foot - Plantar flexion of ankle *Application* - passes posteroinferiorly to the lateral malleolus and under the foot from the outside to under the inner surface. - because of its line of pull, it's a strong evertor and assists in plantar flexion. *Origin*: - Head and upper two-thirds of the lateral surface of the fibula. *Insertion*: - Undersurfaces of the medial cuneiform and first metatarsal bone. *Innervation*: - Superficial peroneal nerve (L4, L5, S1) *Location*: - posterior/lateral

Peroneus (fibularis) Brevis

*Action* - Eversion of the foot - Plantar flexion of ankle *Application* - passes posteroinferiorly to the lateral malleoulus to pull on the base of the fifth metatarsal. - is a primary evertor of the foot and assists in plantar flexion. - it also aids in maintaining the lateral longitudinal arch as it depresses the foot. *Origin*: - Mid to lower two-thirds of the lateral surface of the fibula *Insertion*: - Tuberosity of the fifth metatarsal *Innervation*: - Superficial peroneal nerve (L4, L5, S1) *Location*: - Posterior/lateral

Peroneus Tertius (fibularis)

*Action* - Eversion of the foot - Dorsiflexion of ankle *Application* - *absent in some humans* - assists in dorsiflexion and eversion, which some authorities rever to it as the fifth tendon of the extensor digitorum longus. *Origin*: - Distal third of the anterior fibula *Insertion*: - Superior aspect of the base of the fifth metatarsal *Innervation*: - Deep Peroneal nerve (L4, L5, S1) *Location*: -Anterior/lateral

Extensor Digitorum Longus

*Action* - Extension of the four lesser toes at the metatarsophalangeal and proximal and distal interphalangeal joints. (MTP, PIP, DIP) - Dorsiflexion of ankle - Eversion of the foot *Application* - Strength is necessary here in order to maintain balance between the plantar and dorsal flexors. *Origin*: - Lateral condyle of the tibia, head of the fibula, and upper two-thirds of the anterior surface of the fibula *Insertion*: - Top of the middle and distal phalanxes of the four lesser toes *Innervation*: - Deep peroneal nerve (L4, L5, S1) *Location*: - Anterior

Flexor Digitorum Longus

*Action* - Flexion of the four lesser toes, at the metatarsophalangeal and the proximal and distal interphalangeal joints. (MTP, PIP, DIP) - Plantar flexion of ankle - Inversion of the foot *Application* - passing down the back of the lower leg under the medial malleolus and then forward, the flexor digitorum longus muscle draws the four lesser toes down into flexion towards and the heel as it plantarflexes the ankle. - it is important in helping other foot muscles maintain the longitudinal arch. *Origin*: - Middle third of the posterior surface of the tibia. *Insertion*: - Base of the distal phalanx of the four lesser toes *Innervation*: - Tibial nerve (L5, S1) *Location*: - Posterior

Tensor Fasciae Latae

*Action*: - Abduction of the hip - Flexion of the hip - Tendency to rotate the hip internally as it flexes - Anterior pelvic rotation *Application*: - Aids in preventing external rotation of the hip as it's flexed by other flexor muscles. - *used when flexion and internal rotation take place.* - although a weak movement, it* helps direct the leg forward* so that the foot is placed straight forward when walking and running. - From the supine position, raising the leg with definite internal rotation of the femur will call it into action. --- Hip abduction on side position *Origin*: - Anterior iliac crest and surface of the ilium just below the crest. *Insertion*: - 1/4 of the way down the thigh into the iliotibial tract, which in tun inserts onto Gerdy's tubercle of the anterolateral tibial condyle. *Innervation*: - Superior gluteal nerve (L4, L5, S1)

Gluteus Medius

*Action*: - Abduction of the hip - Lateral pelvic rotation to ipsilateral side - *Anterior fibers*: internal rotation,flexion of the hip and anterior pelvic rotation - *Posterior fibers*: external rotation, extension of the hip and posterior pelvic rotation. *Application*: - Typically the action along side the gluteus minimus when walking, is as the weight is suspended on one leg, they prevent the opposite pelvis from sagging. - *weakness of the gluteus medius and minimus can result in a Trendelenburg gait* which is characterized as by the trunk lurching to the side of the weakness when the controlateral pelvis drops. --- side-laying leg raises or hip abductions *Origin*: - Lateral surface of the ilium just below the crest *Insertion*: - Posterior and middle surfaces of the greater trochanter of the femur *Innervation*: - Superior gluteal nerve (L4, L5, S1

Gluteus Minimus

*Action*: - Abduction of the hip - Lateral pelvic rotation to ipsilateral side - Internal rotation as the femur abducts - Flexion of the hip - Anterior pelvic rotation *Application*: - along side the Gluteus Medius are both used in powerfully maintaining proper hip abduction while running. --- Running, hopping and skipping as body weight is shifted forcefully from one foot to the other. *Origin*: - Lateral surface of the ilium just below the origin of the gluteus medius. *Insertion*: - Anterior surface of the greater trochanter of the femur *Innervation*: - Superior gluteal nerve (L4, L5, S1)

Adductor Longus

*Action*: - Adduction of the hip - Assists in flexion of the hip - Assists in anterior pelvic rotation *Origin*: - Anterior pubis just below its crest *Insertion*: - Middle third of the linea aspera *Innervation*: - Obturator nerve (L3, L4)

Adductor Brevis

*Action*: - Adduction of the hip - External rotation as it adducts the hip - Assists in flexion of the hip - Assists in anterior pelvic rotation *Application*: - along with the other adductor muscles, provide powerful movement of the thighs toward each other. -- Squeezing the thighs together. *Origin*: - front of the inferior pubic ramus just below the origin of the adductor longus. *Insertion*: - lower two-thirds of the pectineal line of the femur and upper half of the medial lip of the lineas aspera *Innervation*: - Obturator nerve (L3-L4)

Adductor Magnus

*Action*: - Adduction of the hip - External rotation as the hip adducts - Extension of the hip *Application*: - used in the breaststroke kick and in horseback riding. *Origin*: - Edge of the entire ramus of the pubis and the ischium and ischial tuberosity *Insertion*: - whole length of the linea aspera, inner condyloid ridge and adductor tubercle *Innervation*: - Anterior: obturator nerve (L2-L4) - Posterior: sciatic nerve (L4, L5, S1-S3)

Gracilis

*Action*: - Adduction of the hip - Weak flexion of the knee - Internal rotation of the hip - Assists with flexion of the hip - Weak internal rotation of the knee *Application*: - also known as the *Adductor Gracilis*, performs as other adductors, but adds some weak assistance to knee flexion --- is in conjunction with the other adductors to perform the breaststroke kick and riding a horse. *Origin*: - Anteromedial edge of the descending ramus of the pubis *Insertion*: - Anterior medial surface of the tibia just below the condyle *Innervation*: - Obturator nerve (L2-L4)

Gluteus Maximus

*Action*: - Extension of the hip (powerful) - External rotation of the hip - Upper fibers: assist in hip abduction - Lower fibers: assist in hip adduction - Posterior pelvic rotation *Application*: - comes into action when movement of the pelvis and the femur approaches and goes beyond 15 degrees of extension. As a result, it *is not used extensively* in ordinary walking. - *Important for extension of the thigh with external rotation* - Powerful extension of the thigh in returning from a squat, especially with a BB. --- Running, hopping, skipping and jumping. *Origin*: - Posterior 1/4 of the crest of the ilium, posterior surface of the sacrum and coccyx near the ilium and fascia of the lumbar area. *Insertion*: - Oblique ridge (gluteal tuberosity) on the lateral surface of the greater trochanter and the iliotibial band of the fasciae latae *Innervation*: - Inferior gluteal nerve (L5, S1, S2)

Vastus Medialis (internus) (Quadriceps Group)

*Action*: - Extension of the knee *Application*: - Important in maintaining patellofemoral stability because of the oblique attachment of its distal fibers to the superior medial patella. -- Known as the (*VMO*) Vastus Medialis Obliquus. -- Utilized in the last 10 to 20 degrees of the knee extension. *Origin*: - Whole length of the linea aspera and the medial condyloid ridge *Insertion*: - Medial halt of the upper border of the patella and patellar tendon to the tibial tuberosity *Innervation*: - Femoral nerve (L2-L4)

Vastus Intermedius (Quadriceps Group)

*Action*: - Extension of the knee *Application*: - The *Vasti* muscles are primarily responsible for extending the knee while the hip is flexed or being flexed. *Origin*: - Upper two-thirds of the anterior surface of the femur *Insertion*: - Upper border of the patella and patellar tendon to the tibial tuberosity *Innervation*: - Femoral nerve (L2-L4)

Soleus

*Action*: - Plantar flexion of ankle *Application*: - *this muscle is one of the most important plantar flexors of the ankle; especially when the knee is flexed* - some anatomists believe that is nearly as important in this movement as the gastrocnemius. - used whenever the ankle plantar flexes and any movement with body weight on the foot with the knee flexed or extended calls it into action. - Running, jumping, hopping, skipping and dancing on the toes are all exercises that depend heavily on the soleus. *Origin*: - Posterior surface of the proximal fibula and proximal two-thirds of the posterior tibial surface *Insertion*: - Posterior surface of the calcaneus via the Achilles tendon *Innervation*: - Tibial nerve (S1, S2) *Location*: - Posterior

the Deep Six Lateral Rotator Muscles: 1 - Piriformis 2 - Gamellus Superior 3 - Gemellus Inferior 4 - Obturator Externus 5 - Obturator Internus 6 - Quadratus Femoris

*Action*: - External rotation of the hip *Application*: - The Six Lateral rotators are used powerfully in movements of external rotation of the femur, as in sports in which an individual takes off on one leg from preliminary internal rotation. -- Throwing a baseball, swinning a bat, involving the rotation of the hip. -- *tightness in the piriformis may contribute to compression of the sciatic nerve.* *Origin*: - Anterior sacrum, posterior portions of the ischium and obturator foramen *Insertion*: - Superior and posterior aspect of the greater trochanter. *Innervation*: - Piriformis: first and second sacral nerve (S1, S2) - Gamellus Superior: Sacral nerve (L5, S1, S2) - Gemellus Inferior: branches from sacral plexus (L4, L5, S1, S2) - Obturator Externus: obturator nerve (L3, L4) - Obturator Internus: branches from sacral plexus (L4, L5, S1, S2) - Quadratus Femoris: Branches from sacral plexus (L4, L5, S1)

Pectineus

*Action*: - Flexion of the hip - Adduction of the hip - External rotation of the hip - Anterior pelvic rotation *Application*: - as it contracts, it tends to rotate the pelvis anteriorly. The abdominal muscles pull up on the pelvis in front to prevent this tilting action. *Origin*: - Space 1 inch wide on the front of the pubis just above the crest (pectineal line). *Insertion*: - Rough line leading from the lesser trochanter down to the linea aspera (pectineal line of the femur) *Innervation*: - Femoral nerve (L2-L4)

Iliopsoas

*Action*: - Flexion of the hip - Anterior pelvic rotation - External rotation of the hip - Transverse pelvis rotation contralaterally when ipsilateral femur is stabilized. - Flexion of lumbar spine by *Psoas Major and Minor* - Lateral flexion of lumbar spine *Psoas Major and Minor* - Lateral pelvic rotation to contralateral side *Psoas Major and Minor* *Application*: - Iliopsoas is commonly referred as one muscle, but it is composed of the Iliacus and Psoas Major. - *The Psoas Minor attaches on the pubis above the hip joint therefore does not act on the hip joint and does not contribute to the iliopsoas muscle.* - Iliopsoas muscle is powerful in actions such as raisin the lower extremity from the floor while in a supine position. - Psoas Major's orientation on the lower back tends to pull the back anteriorly or in a supine position pulls up the lower back as the thigh is raised, for this reason lower back problems are often aggravated by this activity. abdominal muscles are often used to prevent back strain by pulling up on the front of the pelvis to flatten the back. *Origin*: - Illiacus: inner surface of the ilium - Psoas Major and Minor: lower boarders of the transverse processes (L1-L5), sides of the bodies of the last thoracic vertebra (T12), lumbar vertebrae (L1-L5), intervertebral fibrocartilages, and base of the sacrum. *Insertion*: - Iliacus and Psoas Major: Lesser trochanter of the femur and shaft just below. - Psoas Minor: pectineal line (of pubis) and iliopectineal eminence. *Innervation*: Lumbar nerve femoral nerve (L2-L4)

Rectus Femoris (Quadriceps Group)

*Action*: - Flexion of the hip - Extension of the knee - Anterior Pelvic rotation *Application*: - Pulling from the anterior inferior iliac spine of the ilium the rectus femoris muscle has a tendency to rotate the pelvis, down in front and up in back. Only the abdominal muscles prevent this from occurring. - *If the abdominal wall is relaxed it results in an increased lumbar curve because the pelvis is not being held up.* - Powerful extensor of the knee when hip is extended but is weaker when the hip is flexed. *Origin*: - Anterior inferior iliac spine of the ilium and groove (posterior) above the acetabulum. *Insertion*: - Superior aspect of the patella and patellar tendon to the tibial tuberosity. *Innervation*: - Femoral nerve (L2-L4)

Sartorius

*Action*: - Flexion of the hip - Flexion of the knee - External rotation of the thigh as it flexes the hip and knee - Abduction of he hip - Anterior pelvic rotation - Weak internal rotation of the knee *Application*: - Tends to pull the pelvis anteriorly (down in front) as this muscle contracts. Abdominal muscles must prevent this by posteriorly rotating the pelvis (pulling up in front), thus flattening the lower back. - this muscle is a *Two-joint muscle*, is effective as a hip flexor or a knee flexor. - referred to as the *tailor's muscle*, because it's active in all hip and knee movements used to sit in the tailors position. - *Longest muscle in the body*

Biceps Femoris (Hamstring group)

*Action*: - Flexion of the knee - Extension of the hip - External rotation of the hip - External rotation of the flexed knee - Posterior pelvic rotation *Application*: -- Hamstring curls - *the Hamstring muscle is made up of the Semitendinosus, Semimembranous and Biceps Femoris.* these muscles working together with the gluteus maximus in the extension of the hip when the knees are straight or nearly so. ---Running, jumping, skipping, and hopping using all these muscles. *Origin*: - Long Head: ischial tuberosity - Short Head: Lower half of the linea aspera, and lateral condyloid ridge *Insertion*: - Lateral condyle of the tibia and head of the fibula *Innervation*: - Long Head: sciatic nerve - tibial division (S1-S3) - Short Head: sciatic nerve - peroneal division (L5, S1, S2)

Semimembranous (Hamstring group)

*Action*: - Flexion of the knee - Extension of the hip - Internal rotation of the hip - Internal rotation of the flexed knee - Posterior pelvic rotation *Application*: - this muscle and the Semitendinosus are responsible for internal rotation of the knee, along with the popliteus muscle. - the manner in which they cross the joint is important in *providing dynamic* medial stability to the knee joint -- Leg curls and Internal rotation of the knee *Origin*: - Ischial tuberosity *Insertion*: - Posteromedial surface of the medial tibial condyle *Innervation*: - Sciatic nerve - tibial division (L5, S1, S2)

Popliteus

*Action*: - Flexion of the knee - Internal rotation of the knee as it flexes *Application*: - Is the *only true Flexor* of the leg at the knee --- All the other flexors are two joint muscles. - Vital in providing posterolateral stability to the knee - Assists in internal rotation of the lower leg at the knee and is *crucial* in internally rotating the knee to unlock it from the "screwed home" full extension position. *Origin*: - Posterior surface of the lateral condyle of the femur *Insertion*: - Upper posterior medial surface of the tibia *Innervation*: - Tibial nerve (L5, S1)

Gastrocnemius

*Action*: - Plantar flexion of ankle - Flexion of the knee *Application*: - Running jumping, hopping and skipping all depend significantly on this muscle; and propelling the body upward and forward depending significantly on the soleus - is a biarticular muscle, that is more effective as a knee flexor if the ankle is in dorsoflexion and more at plantar flexion of the foot if the knee is held in extension. - The Gastrocnemius and Soleus together are known as the Triceps Surea. -- the Triceps refer to the heads of the medial and lateral gastrocnemius and soleus and Surae referring to the calf *Origin*: - Medial head: posterior surface of the medial femoral condyle - Lateral head: posterior surface of the lateral femoral condyle *Insertion*: - Posterior surface of the calcaneus via the Achilles tendon *Innervation*: - Tibial nerve (S1, S2) *Location*: - Posterior

Tibialis Posterior

*Action*: - Plantar flexion of ankle - Inversion of the foot *Application*: - Passing down the back of the leg, under the medial malleolus, then forward to the navicular and medial cuneiform bones, this muscle pulls down from the underside and when contracted concentrically, inverts and plantarflexes the foot; as a result, *it supports the medial longitudinal arch.* - *Shine Splints*: used to describe a chronic condition, in which the tibialis posterior, tibialis anterior and extensor digitorum longus muscles are inflamed- Tendonitis of one or more of these structures may result in a stress fracture, periositis, tibial stress syndrome or compartment syndrome. common in long distance runners and sprinters. - in plantar flexion and inversion gives support to the longitudinal arch of the foot. *Origin*: - Posterior surface of the upper half of the interossues membrane and adjacent surfaces of the tibia and fibula. *Insertion*: - Inferior surfaces of the navicular, cuneiform, and cuboid bones, and bases of second, third, and fourth metatarsals *Innervation*: - Tibial nerve (L5, S1) *Location*: - Posterior

Vastus Lateralis (externus) (Quadriceps Group)

*Action*: - Extension of the knee *Application*: - all of the *Vasti* muscles function with the rectus femoris in knee extension. ---- jumping, running, walking and must be used in order to keep the knee straight when standing. -- has a slightly superior pull on the patella and as a result is blamed for common lateral patellar subluxation and dislocation problems. *Origin*: - Intertrochanteric line, anterior and inferior borders of the greater trochanter, gluteal tuberosity, upper half of the linea aspera and entire lateral intermuscular septum. *Insertion*: - Lateral border of the patella and patellar tendon to the tibial tuberosity *Innervation*: - Femoral nerve (L2-L4)

Semitendinosus (Hamstring group)

*Action*: - Flexion of the knee - Extension of the hip - Internal rotation of the hip - Internal rotation of the flexed knee - Posterior pelvic rotation *Application*: - *two-joint muscle* is most effective when contracting to either extend the hip or flex the knee. --- Hamstring curls or Leg Curls - Used in ordinary walking as extensors of the hip and allowing the gluteus maximus to relax in the movement.

Ankle Plantar Flexion

*Agonists* - Gastrocnemius - Soleus -- Flexor digitorum longus -- Flexor hallucis longus -- Peroneus (fibularis) longus -- Peroneus (fibularis) brevis -- Plantaris -- Tibialis posterior

Ankle Dorsiflexion

*Agonists* - Tibialis anterior - Extensor digitorum longus - Peroneus (fibularis) tertius - Extensor hallucis longus

Intrinsic Muscles of the foot

*First (superficial) Layer*: abductor hallucis, flexor digitorum brevis, abductor digiti minimi (quinti) *Second Layer*: quadratus plantae, lumbricals (four) *Third Layer*: Flexor hallucis brevis, adductor hallucis, flexor digiti minimi (quinti) brevis. *Fourth (deep) Layer*: Dorsal interossei (four), plantar interosseo (three). page 318

Serratus Anterior

Action: - Abduction (protraction): draws the medial border of the scapula away from the vertebrae. - Upward rotation: longer, lower fibers tend to draw the inferior angle of the scapula farther away from the vertebrae, thus rotating the scapula upward slightly. - Draws scapula forward with slight upward rotation. - used strongly when doing push-ups especially true in the last 5-10 degrees. Exercises: Bench Press and overhead press --Ex: throwing a baseball, punching, shooting and guarding. Origin: - surface of the upper nine ribs at the side of the chest. Insertion: - anterior aspect of the whole length of the medial border of the scapula.

Pectoralis Minor Muscle

Action: - Abduction (protraction): draws the scapula forward and tends to tilt the lower border away from the ribs. - Downward rotation: as it abducts, it draws the scapula downward. - Depression: when the scapula is rotated upward, it assists in depression. Innervation: - medial pectoral nerve (C8-T1) - in combination with the Serratus anterior is used in true abduction (protraction) without rotation such as a Push-up. Origin: - Anterior surfaces if the third to fifth ribs. Insertion: - Coracoid process of the scapula Innervation: - Medial pectoral nerve (C8-T1).

Latissimus Dorsi

Action: - Adduction of the glenohumeral joint. - Extension of the glenohumeral joint. - Internal rotation of the GH joint - Horizontal abduction of the GH joint -- Lattissimus Dorsi means the broadest muscle of the back. Origin: - Posterior crest of the ilium, back of the sacrum and spinous process of the lumbar and lower six thoracic vertebrae (T6-T12); slips from the lower three ribs. Insertion: - Medial lip of the interubercular groove of the humerus, just anterior of the insertion of the teres major. Innervation: -Thoracodorsal nerve (C6-C8)

Triceps Brachii

Action: - All Head: extension of the elbow - Long Head (LH): *Long head only* Extension, adduction and horiztonal abduction of the shoulder joint (GH). -- Push-ups and any balancing movement in ANY push-up movement in the upper extremities. -- The long head is an important extensor of the shoulder joint. Origin: - Long head (LH): Infragenoid tubercle of scapula. - Lateral Head (LatH): Upper half of posterior surface of the humerus - Medial head (MH): Distal 2/3rds of posterior surface of the humerus Insertion: - Olecranon process of ulna. Location: - Posteriorly Innervation: - Radial nerve (C7, C8)

Splenius muscle (Capitis, Cervicis)

Action: - Both sides: extension of the head (splenius capitis) and neck (splenius cervicis and capitis). - Right side: Rotation and lateral flexion to the right. - Left side: rotation and lateral flexion to the left. -- Any movement of the head and neck into extension, particularly extension and rotation. Origin: - Splenius Cervicis: spinous processes of the third through sixth thoracic vertebrae.C7-T4 (CA) - Splenius Capitis: lower half of the ligamentum nuchae and spinous process of the seventh cervical and upper three or four thoracic vertebrae. T3-6 (CE) Location: Posterior Insertion: - Splenius Cervicis: transverse processes of the first three cervical vertebrae. - Splenius Capitis: mastoid process and occipital bone.

External Oblique abdominal muscle

Action: - Both sides: lumbar flexion - Posterior pelvic rotation - Right side: lumbar lateral flexion to the right and rotation to the left, lateral pelvic rotation to the left. - Left side: Lumbar lateral flexion to the left and rotation to the right, lateral pelvic rotation to the right. --Rotation of the trunk when working independently of one another, when together they aide the rectus. Origin: - Borders of the lower 8 ribs at the side of the chest, dovetailing with the serratus anterior muscle. Insertion: - Anterior half of the crest of the ilium, the inguinal ligament, the crest of the pubis and the fascia of the rectus abdominis muscle at the lower front. Innervation: - Intercostal nerve (T8-T12, iliohypogastric nerve (T12, L1) and ilioinguinal nerve (L1).

Internal Oblique abdominal muscle

Action: - Both sides: lumbar flexion - Posterior pelvic rotation - Right side: lumbar lateral flexion to the right and rotation to the right, lateral pelvic rotation to the left. - Left side: lumbar lateral flexion to the left and rotation to the left, lateral pelvic rotation to the right. -- The left rotates to the left and the right to the right. Origin: - Upper half of the inguinal ligament, anterior two-thirds of the crest of the ilium and lumbar fascia Insertion: - Costal cartilages of the 8th, 9th, and 10th ribs and the linea alba. Innervation: -Intercostal nerves (T8-T12), iliohypogastric nerve (T12, L1) and ilioinguinal nerve (L1).

Levator scapulae

Action: - Elevation of scapula Origin: - Transverse process of C1-C4 Insertion: - Medial border of scapula above spine

Teres Major

Action: - Extension of the GH joint, particularly from the flexed position to the posteriorly extended position. - Internal rotation of the GH joint. - Adduction of the GH joint, particularly from the abducted position down to the side and toward the midline of the body. -- this muscle is only effective when the rhomboid muscles stabilize the scapula or move the scapula in a downward rotation. Origin: - Posteriorly on the inferior third of the lateral border of the scapula and just superior to the inferior angle. Insertion: - Medial lip of the intertubercular groove of the humerus just posterior to the insertion of the latissimus dorsi. Innvervation: - Lower subscapular nerve (C5,C6)

Anconeus

Action: - Extension of the elbow -- the chief function is to pull the synovial membrane of the elbow joint out of the way of the advancing olecranon process during extension of the elbow. -- is strengthened during any elbow extension exercise and contracts along with the triceps. Origin: - Posterior surface of lateral condyle of the humerus. Insertion: - Posterior surface of upper ulna and olecranon Location: - Posteriorly Innervation: - Radial Nerve (C7, C8)

Erector Spinae Muscles: Sacrospinalis

Action: - Extension, lateral flexion and ipsilateral rotation of the spine and head. - Anterior pelvic rotation. - Lateral pelvic rotation to contralateral side. Iliocostalis: lateral layer. - origin: medial iliac crest, thoracolumbar aponeurosis from sacrum, posterior ribs 3-12. - insertion: posterior ribs 1-12, cervical 4-7 transverse processes. Longissimus: middle layer - origin: medial iliac crest, thoracolumbar aponeurosis from sacrum, lumbar 1-5 transverse processes and thoracic 1-5 transverse processes, cervical 5-7 articular processes. - insertion: cervical 2-6 spinous processes, thoracic 1-12 transverse processes, lower nine ribs, mastoid process Spinalis: medial layer - origin: ligamentum nuchae, seventh cervical spinous process, thoracic 11 and 12 spinous processes, and lumbar 1 and 2 spinous processes. - insertion: secound cervical spinous process, thoracic 5-12 spinous processes, occipital bone. Innervation: - posterior branches of the spinal nerves

Teres Minor

Action: - External Rotation of the GH joint - Horizontal abduction of the GH joint - Extension of the glenohumeral joint - Stabilization of the humeral head in the glenoid fossa Origin: - Posteriorly on the upper and middle aspect of the lateral border of the scapula Insertion: - posteriorly on the greater tubercle of the humerus Innervation: - Axillary nerve (C5, C6)

Infrasoinatus

Action: - External rotation of the GH joint - Horizontal abduction of the GH joint. - Extension of the GH joint - Stabilization of the humeral head in the glenoid fossa. Origin: - Posterior surface of scapula below spine. Insertion: - Greater tubercle on posterior side of the humerus. Innervation: - Suprascapular nerve (C5,C6)

Biceps Brachii

Action: - Flexion of the elbow - Supination of the forearm - Weak flexion of the shoulder joint - Weak abduction of the shoulder joint when the shoulder joint is in external rotation. -- Is commonly known as two-joint (shoulder and elbow) or biarticular muscle. However it technically should be a three joint muslce (multiarticular) b/c shoulder, elbow and radioulnar. Origin ShortHead (SH): Coracoid process LongHead (LH): Supraglenoid tubercle Insertion: - Radial tuberosity - Bicipical aponeurosis Location: Anteriorly Innervation: - Musculocutaneous nervea and radial, medial nerves (C5,C6)

Transversus abdominis muscle

Action: - Forced expiraton by pulling the abdominal wall inward. -- chief muscle of forced expiration and is effective with the other abdominal muscles to hold the abdomen flat. Origin: - lateral third of the inguinal ligament, inner rim of the iliac crest, inner surface of the costal cartilages of the lower six ribs and lumbar fascia. Insertion: - crest of the pubis and the iliopectineal line abdominal aponeurosis to the linea alba Innervation: - intercostal nerve (T17-T12), iliohypogastic nerve (T12,L1) and ilioinguinal nerve (L1).

Subscapularis

Action: - Internal rotation of the GH joint - Adduction of the GH joint. - Extension of the GH joint. - Stabilization of the humeral head in the glenoid fossa. -- rotator cuff muscle tha holds the head of the humerus in the glenoid foss from in front and below. Origin: - Entire anterior surface of the subscapular fossa. Insertion: - Less tubercle of the humerus. Innervation: - Upper and lower subscapular nerve (C5,C6)

Pronator Teres

Action: - Pronation of the forearm -- movement of this muslce alone brings the back ot the hand to the face as it contracts -- Pronation of the forearm with a dumbbell in the hand localizes action and develops this muscle. Origin: - Distal part of the medial condyloid ridge of humerus, medial side of the proximal ulna Insertion: - Middle third ofl ateral surface of the radius Innervation: - Median nerve (C6, C7)

Pronator Quadratus

Action: - Pronation of the forearm -- commonly used in turning a screwdriver, to take out a screw. Origin: - Distal 1/4th of anterior side of the radius Insertion: - Distal 1/4th (fourth) of the anterior side of the radius. Location: - Anteriorly Innervation: - Median Nerve (palmar interosseous branch), (C6,C7)

Rhomboid (major and minor)

Action: - Rhomboid major & minor muscles work together - Retraction (adduction) - Downward rotation: from upward rotated position they draw scapula in downward rotation - Elevation: slight upward movement accompanying adduction Origin: - Spinous process of C7 and T1-T5 Insertion: - Medial border of scapula below spine

Subclavius muslce

Action: - Stabilization and protection of the sternoclavicular joint. - depression and abduction (protraction). - assists abduction and depression of the clavicle and the shoulder girdle, also protects and stablizes the sternoclavicular joint during upper extremity movements. - strengthened during activites such as dips, push-ups. Origin: - Superior aspect of the first rib at its junction with its costal cartilage. Insertion: - inferior groove in the midportion of the clavicle. Innervation: - Nerve fibers from C5 and C6

Supinator

Action: - Supination of the forearm Origin: - Lateral epicondyle of the humerus and neighboring posterior part of the ulna. Insertion: - Lateral surface of the proximal radius just below the head. Innervation: - Radial nerve (C6)

Pectoralis Major

Action: - Upper fibers (clavicular head): internal rotation, horizontal adduction, flexion up to about 60 degress, abduction (once the arm is abducted to 0 degress, the upper fibers assist in further abduction) and adduction (with the arm below 90 degrees of abduction) of the glenohumeral joint. - Lower fibers (sternal head): internal rotation, horizontal adduction, and adduction and extension of the glenohumeral joint from a flexed position to the anatomical position. Origin: - Upper fibers (clavicular head): medial half of the anterior surface of the clavical. - Lower fibers (sternal head): anterior surface of the costal cartilages of the first six ribs, and adjacent portion of the sternum. Insertion: - Flat tendon 2 or 4 inches wide to the lateral lip of the intertubercular groove of the humerus. Innervation: - Upper fibers: lateral pectoral nerve (C5-C7) - Lower fibers: medial pectoral nerve (C8, T1)

Trapezius

Action: - Upper fibers: elevation of scapula, extension & rotation of head - Middle fibers: elevation, upward rotation & adduction (retraction) - Lower fibers: depression, adduction & upward rotation. Origin: - Upper fibers: base of skull, occipital protuberance, and posterior ligaments of the neck, spinous process of C 7 and T1-1T2. Insertion: - Posterior aspect of lateral 3rd clavicle, medial border of acromion process, and upper border of scapular spine

Sternocleidomastoid muscle

Action: - extension of the head at the atlantooccipital joint. - flexion of the cervical spine. - Ride side: rotation to the left and lateral flexion to the right. - Left side: rotation to the right and lateral flexion to the left. -- Primarily responsible for flexion and rotation of the head and neck. Origin: - Manubrium of the sternum - Anterior superior surface of the medial clavicle Location: Lateral Insertion: - Mastoid process Innervation: - Spinal accessory nerve (Cr11, C2, C3)

Quadratus Lumborum Muscle

Action: - lateral flexion to the ipsilateral side - stabilizes the pelvis and lumbar spine - extension of the lumbar spine - anterior pelvic rotation - lateral pelvic rotation to contralateral side. -- Important in lumbar lateral flexion and in elevating the pelvis on the same side in the standing position. Origin: - posterior inner lip of the iliac crest Insertion: - approximately one-half the length of the lower boarder of the 12th rib and the transverse process of the upper four lumbar vertebrae. Innervation: -Branches of T12, L1 nerves.

Deltoid

Action: - Anterior fibers: abduction, flexion, horizontal adduction, and internal rotation of the glenohumeral joint. - Middle fibers: abduction of the glenohumeral joint. - Posterior fibers: abduction, extension, horizontal abduction, and external rotation of the glenohumeral joint -- used in any lifing movement, stabilizes the scapula as the deltoid pulls the humerus. Origin: - Anterior fibers: from the clavicle toward the anterior humerus during resisted flexion or horizontal adduction. Insertion: - Deltoid tuberosity on the lateral humerus. Innervation: - Axillary Nerve (C5,C6)

Coracobrachialis

Action: - Flexion of the GH joint - Adduction of the GH joint - Horizontal adduction of the glenohumeral joint -- not powerful but, move the arm horizontally toward and across the chest. Origin: Coracoid process of the scapula Insertion: - Middle of the medial border of the humeral shaft.

Brachioradialis

Action: - Flexion of the elbow (best when in neutral position) - Pronation of the forearm from supinated position to neutral. - Supination of the forearm from pronated position to neutral. -- is part of three muscles, known as "the mobile Wad of Three" on the lateral forearm. Other two muscles are extensor carpi radialis brevis and extensor carpi radialis longus. Origin: - Distal 2/3rds of lateral condyloid ridge of humerus Insertion: - Lateral surface of the distal end of the radius at styloid process Location: - Anteriorly Innervation: - Radial nerve (C5, C6)

Rectus Abdominis muscle

Action: (Trunk Flexion) - Both sides: lumbar flexion - Posterior pelvic rotation - Right side: weak lateral flexion to the right. - Left side: weak lateral flexion to the left. --Controls the tilt of the pelvis and the consequent curvature of the lower spine. -- Flattens lower back Origin: - crest of the pubis Insertion: - cartilage of the fifth, sixth and seventh ribs and the xiphoid process Innervation: - Intercostal nerves (T7-T12)

Multifidus

Actions - Lateral flexion - Trunk extension Origin - Posterior sacrum - Superior iliac spine Insertion - Spinous process of the vertebrae, excluding C1