Muscle Origin & Insertions

Front 1

Sternocleidomastoid

Back 1

O --> manubrium & medial clavicle

I --> mastoid process & superior nuchal line of occipital bone

Front 2

Mylohyoid

Back 2

O --> medial surface of mandible

I --> hyoid bone & median raphe

Front 3

Thyrohyoid

Back 3

O --> thyroid cartilage

I --> hyoid bone

Front 4

Pectoralis Major

Back 4

O --> sternal end of clavicle, sternum, cartilage of ribs 1 - 6 & aponeurosis of external oblique

I --> sulcus & intertuburcular groove

Front 5

External Intercostals

Back 5

O --> inferior border of rib above

I --> superior border of rib below

Front 6

Diaphragm

Back 6

O --> internal surface of rib cage & sternum, costal cartilages of last 6 ribs & lumbar vertebrae

I --> central tendon

Front 7

Trapezius

Back 7

O --> occipital bone, spine of C7 & all thoracic vertebrae

I --> acromion, spine of scapula & lateral 1/3 of the clavicle

Front 8

Latissimus Dorsi

Back 8

O --> lower 6 thoracic vertebrae, lumbar vertebrae, lower 3 to 4 ribs & iliac crest

I --> floor of intertubercular sulcus of humerus

Front 9

Rhomboid Major

Back 9

O --> spinous processes of T2 - T5

I --> medial border of scapula

Front 10

Rhomboid Minor

Back 10

O --> spinous processes of C7 & T1

I --> medial border of scapula

Front 11

Rectus Abdominis

Back 11

O --> pubic crest & symphysis

I --> xiphoid process & costal cartilage of ribs 5 - 7