Origin, Insertion, and Action

What is the Origin of Sterncleidomastoid?

Sternum and Clavicle

What is the Insertion of Sterncleidomastoid?

Mastoid process of temporal bone

What is the Action of Sterncleidomastoid?

Acting together (bilateral), flex cervical portion of vertebral column and head; acting singly (unilateral), laterally flex and rotate head to side opposite contracting muscle

What is the Origin of Trapezius?

Occipital bone, ligamentum nuchae, and spinous process of thoracic vertebrae

What is the Insertion of Trapezius?

Clavicle and scapula (acromion and scapular spine)

What is the Action of Trapezius?

Depends on active region and state of other muscles; (1) may elevate, retract, depress, or rotate scapula upward, (2) elevate clavicle, or (3) extend neck

What is the Origin of Latissimus Dorsi?

Spines of inferior six thoracic vertebrae, lumbar vertebrae, crests of sacrum and ilium, inferior four ribs, inferior angle of scapula

What is the Insertion of Latissimus Dorsi?

Intertubercular groove of humerus

What is the Action of Latissimus Dorsi?

Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly

What is the Origin of Pectoralis Major?

Clavicle, sternum, and cartilage of 2nd to 6th ribs (sternocostal head)

What is the Insertion of Pectoralis Major?

Greater tubercle and intertubercular groove of humerus

What is the Action of Pectoralis Major?

As a whole, adducts and medially rotates arm at shoulder joint; clavicular head alone flexes arm at shoulder joint

What is the Origin of Rectus Abdominis?

Pubic crest and pubic symphysis

What is the Insertion of Rectus Abdominis?

Cartilage of 5th to 7th ribs and xiphoid process

What is the Action of Rectus Abdominis?

Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination and forced expiration and childbirth

What is the Origin of Deltoid?

(1) Anterior fibers: Acromial extremity of clavicle, (2) middle fingers: Acromion of scapula, (3) Posterior fibers spine of scapula

What is the Insertion of Deltoid?

Deltoid tuberosity of humerus

What is the Action of Deltoid?

Middle fingers abduct arm at shoulder joint; anterior fibers flex, and medially rotate arm at shoulder joint; posterior fibers extend and laterally rotate arm at shoulder joint

What is the Origin of Biceps Brachii?

(1) Long head: supraglenoid tubercle of the scapula, (2) Short head: Coracoid process of scapula

What is the Insertion of Biceps Brachii?

Radial tuberosity and bicipital aponeurosis

What is the Action of Biceps Brachii?

Flexes forearm at elbow joint, supinates forearm at radioulnar joints, and flexes arm at shoulder joint

What is the Origin of Triceps Brachii?

(1)Long head: projection inferior to glenoid cavity of scapula, (2) Lateral head: lateral and posterior surface of humerus superior to radial groove, (3) Medial head: entire posterior surface of humerus inferior to a groove for the radial nerve

What is the Insertion of Biceps Brachii?

Olecranon of ulna

What is the Action of Biceps Brachii?

Extends forearm at elbow joint and extends arm at shoulder joint

What is the Origin of Rectus Femoris?

Anterior Inferior iliac spine

What is the Insertion of Rectus Femoris?

(RF) Patella via quadriceps tendon and then tibial tuberosity via patellar ligament

What is the Action of Rectus Femoris?

(RF) All 4 heads (of the quadriceps) extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

What is the Origin of Vastus Medialis?

Linea aspera of femur

What is the Insertion of Vastus Medialis?

(VM) Patella via quadriceps tendon and then tibial tuberosity via patellar ligament

What is the Action of Vastus Medialis?

(VM) All 4 heads (of the quadriceps) extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

What is the Origin of Vastus Lateralis?

Greater Trochanter and linea aspera of femur

What is the Insertion of Vastus Lateralis?

(VL) Patella via quadriceps tendon and then tibial tuberosity via patellar ligament

What is the Action of Vastus Lateralis?

(VL) All 4 heads (of the quadriceps) extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

What is the Action of Bicep Femoris?

Long head arises from ishcial tuberosity: short head arises from linea aspera of femur

What is the Insertion of Bicep Femoris?

Head of fibula and lateral condyle of tibia

What is the Action of Bicep Femoris?

(BF) (The hamstring) flex leg at knee joint extend thigh at hip joint

What is the Origin of Semitendinosus?

Ischial Tuberosity

What is the Insertion of Semitendinosus?

Proximal part of medial surface of shaft of tibia

What is the Action of Semitendinosus?

(ST) (The hamstring) flex leg at knee joint extend thigh at hip joint

What is the Origin of Semimembranosus?

Ischial Tuberosity

What is the Insertion of Semimembranosus?

Medial condyle of tibia

What is the Action of Semimembranosus?

(SM) (The hamstring) flex leg at knee joint extend thigh at hip joint

What is the Origin of Gastrocnemius?

Lateral and medial condyles of femur and capsule of knee

What is the Insertion of Gastrocnemius?

Calcaneus by way of calcaneal tendon

What is the Action of Gastrocnemius?

Plantar flexes foot at ankle joint and leg at knee joint

What does Flexor?

Decrease joint angle

What does Extensor?

Increase joint angle

What does Abductor?

Moves bone away from midline

What does Adductor?

Moves bone closer to midline

What does Supinator?

Turns palm superiorly or anteriorly

What does Pronator?

Turns palm inferiorly or posteriorly

What does Levator?

Produces superior movement

What does Depressor?

Produces inferior movement

What does Tensor?

Makes a body part rigid

What does Sphincter?

Decrease size of opening

What does Extension?

Involves an increase in the angle between articulating bones; usually in the sagittal plane

What does Hyperextension?

Continuation of extension beyond the anatomical position

What does Flexion?

Involves a decrease in the angle between articulating bones; usually in the sagittal plane

What does Lateral flexion?

Movement of the torso in the frontal plane

What does Abduction?

Movement of a bone away from the midline; usually in the frontal plane

What is Adduction?

Movement of a bone toward the midline; usually in the frontal plane

What does Circumduction?

A combination of flexion, abduction, extension, and adduction in succession, in which the distal end of a part of the body describes a circle

What does Elevation?

Movement of a part of the body superiorly

What does Depression?

Movement of a part of the body inferioly

What does Supination?

Movement of the forearm in which the palm is turned anteriorly or superiorly

What does Pronation?

Movement of the forearm in which the palm is turned posteriorly or inferiorly

What is Inversion?

Movement of the soles of the foot medially so they face toward from each other

What is Eversion?

Movement of the soles of the foot laterally so they face away from each other

What does Dorsiflexion?

Bending the foot in the direction of the dorsum

What does Plantar Flexion?

Bending the foot in the direction of the plantar surface

What does Protraction?

Movement of a part of the body to the anterior; in the transverse plane

What does Retraction?

Movement of a part of the body to the posterior; in the transverse plane

What does Opposition?

Movement of the thumb across the palm to touch the tips of the fingers on the same hand

What does Rotation?

Movement of a bone around its own longitudinal axis, in the limbs, it may be medial or lateral

What is agonist?

Muscle that is the prime mover, and therefore doing most of the work specific movement

What is Antagonist?

The muscle that opposes the action of the agonist.

What is Synergist?

Muscle that works with assisting the larger agonist muscle