Prime movers/Agonists
(muscles)

- work "leader"
- muscles that produce a specific movement

**brachialis is the prime mover for forearm flexion

Antagonist
(muscles)

- work in opposition
- muscles that oppose particular movement

**triceps brachii is the antagonist for forearm flexion

Synergists
(muscles)

- work together
- muscles that add force to a movement
muscles that reduce undesirable or unnecessary movement

Naming Rules

- Location
- Shape of muscles
- Relative size of muscle
- Direction of muscle fibers
- Number of origins (heads)
- Location of origins and insertions
- Action

Epicranius

- front belly and the occipital belly
- muscle on top of your cranium

Frontal belly

covers the forehead and dome of the skull
Origin: galea aponeurotica
Insertion: Skin of eyebros
Action: raises eye brows and wrinkles forehead skin

Occipital Belly

overlies posterior occipital bone; fixes galea oponeurotica
Origin: occipital and temporal bones
Insertion: galea aponeurotica
Action: fixes aponeurosis and pulls scalp backward

Orbicularis oculi

circular muscle around eye
Origin: frontal and maxillary bones
Insertion: tissue of eyelid
Action: blinks, squints, and draws eyebrows down

Orbicularis Oris

circular muscle around mouth
Origin: maxilla and mandible
Insertion: skin and muscles at angles of mouth
Action: closes lips, purses and protrudes lips, kisses and whistles

Zygomaticus major and minor

muscles extending diagonally from cheek to corner of the mouth.
Origin: zygomatic bone
Insertion: skin and muscle at the corner of mouth
Action: smiles - brings the corber of the mouth toward the bone

Mentalis

V-shaped chin muscle
Origin: mandible
Insertion: skin of chin
Action: protrudes lower lip, wrinkles chin

Buccinator

horizontal muscle, DEEP to masseter (buckle cheek area)
Origin: molar region of maxilla and mandible
Insertion: orbicularis oris
Action: draws corber of mouth laterally, compresses cheek, side-to-side movement - not really smiling

Platysma

sheet-like superficial neck muscle
(turtle neck)
Origin: fascia of chest muscle
Insertion: lower mandible and corber of mouth
Action: depresses mandibles, pulls lower lip back and down

Erector spinae

consist of three columns on each side of the vertebrae
Action: prime mover of back extension when contract together
Action: lateral bending when contract unilaterally
**Sit up straight <--uses both sides simultaneously

Breathing muscles

Diaphragm, external intercostals (11 pairs), internal intercostals (11 pairs)

External intercostals

11 pairs lie between 12 pairs of ribs
Action: elevate rib cage, aid in inspiration, synergists of diaphragm <-- INHALE
MORE SUPERFICIAL MUSCLES

Internal intercostals

11 pairs lie between 12 pairs of ribs; deep to external ones
Action: depress rib cage, aid in forced expiration
**antagonists to diaphragm and external intercostals
EXHALE

Abdominal area and layers

Each layer has three areas - medial and sides
1st layer: Medial = aponeurosis; sides = external obliques
2nd layer: Medial = rectus abdominus; sides = internal obliques
3rd layer: Medial = aponeurosis; sides = transverse abdominis

external oblique

largest and superficial lateral of the abdominal muscles, fibers run downward and medially
Connected to each other through the aponeurosis

Internal oblique

deep to external oblique, fibers run upward and medially
A: when pairs contract simultaneously, aid in flexing and compressing abdominal wall
A: when acts individually, aid in truck rotation and lateral flexion

Transversus abdominis

lateral muscles deep to internal oblique; fibers run horizontally
A: compresses abdominal contents

Rectus abdominis

the only medial muscles - located in the second layer of abdominal area
8 sections, top two can be covered by Pectorals
A: flex and rotate lubar region of vertebral column, depress ribs

Serratus anterior

Anterior Thoracic cage
muscle on the lateral rib cage; deep to scapula.
Origin: ribs 1-8
Insertion: anterior surface of scapula
Action: prime mover to protract and hold scapula against chest
**AKA - Boxer's muscle
zig-zag on the back, then cover the ribs

Trapezius

superficial muscle of posterior thoracic cage
Origin: occipital bone, C7 and all thoracic vertebrae
Insertion: along acrominon and scapula and clavicle
Action: stabilizes, raises, retracts, and rotates scapula <-- shoulder dhrug

Latissimus dorsi

broad, flat lower back muscle on the posterior thoracic cage
Origin: vertebrae and lower ribs
Insertion: humerus
Action: rotates arm medially; used in swimming and hammering
Action: **prime mover of arm extension and adduction <--from out at shoulder in to sides

Deltoid

thick, triangular muscle on posterior thoracic cage
Origin: clavicle, acromion and scapula
Insertion: humerus
Action: prime mover of arm abduction <--to move arm out from side.
Action: antagonist of pectoralis major and latissimus dorsi

Anterior arm muscles

Biceps Brachii, Bracialis, Brachioradialis

Triceps brachii

three-headed large muscle on the posterior arm
Origin: scapula and humerus
Insertion: proximal ulna
Action: prime mover of forearm extension, antagonist of brachialis and biceps brachii
**equivalent of brachialis on the backside

Iliopsoas

A pair of anterior pelvis muscles
Action: prime mover of hip or thigh flexion

Sartorius

Superficial thigh muscle running obliquely - anterior pelvis muscle
**longest muscle in the body
Origin: iliac spine
Insertion: tibia
Action: flexes, abducts, and laterally rotates thigh; aka tailor's muscle
**Take a bow muscle

Quadriceps femoris

group of 4 muscles in the anterior thigh
-Rectus femoris - superficial straight muscle
-Vastus lateralis - forms lateral aspect of thigh
-Vastus medialis - forms medial aspect of thigh
-Vastus intermedius - covered by rectus femoris - a little bit of muscle a lot of aponeurosis
ACTION: a prime mover of knee extension

Adductors

group of three medial muscles - run from the hip bone to the medial thigh
-Magnus adductor
-Longus adductor
-Brevis adductor
ACTION: adducts, flexes, and medially rotates thigh

Hamstrings

Group of three muscles located in the Posterior Thigh
Biceps femoris, Semiteninosus, semimembranosus
Origin: Ischium
Insertion: Tibia
Action: Prime movers of thigh extension and knee flexion

Biceps femoris

lateral,two-headed muscle located in the hamstring-posterior thigh muscles

Semitendinosus

superficial medial smaller muscle located in the hamstring-posterior thigh muscles.
Visually appears half muscle and half tendon

Semimembranosus

medial; broader but deep to semitendonous.
located in the hamstring-posterior thigh muscles
Visually, a big chunk is covered by membrane

Tibialis anterior

superficial anterior muscle in the leg
Origin: tibia
Insertion: Metatarsal bone
Action: prime mover of dorsiflexion

Extensor digitorum longus

Extensor = when you contract this muscle you extend something
digitorum = digits (toes)
longus = long

runs lateral to tibilas anterior
ACTION: prime mover of toe extension

Fibularis

most lateral leg muscle - includes longus and brevis sections
ACTION: dorsi flexes and everts foot

Gastrocnemius

- superficial muscle with two prominent bellies
- calf muscle
- muscle goes halfway to calf then to its tendon.
ACTION: prime mover for plantar flexes when knee is extended; flexes knee when foot is dorsiflexed
**shares the achilles tendon with soleus

Soleus

deep to gastrocnemius - part of the calf muscle
ACTION: prime mover for plantar flexes
**shares the achilles tendon with gastrocnemisu