Torso Muscle Functions

Semispinalis capitis

Extends head and neck, laterally flexes neck

Semispinalis cervicis and thoracis

Extends vertebral column and rotates toward opposite side

Spinalis cervicis

Extends neck

Spinalis thoracis

Extends vertebral column

Longissimus capitis and cervicis

Extends head, rotates and laterally flexes neck to the same side

Longissimus thoracis

extends vertebral column, rotates and laterally flexes neck to the same side

Iliocostalis cervicis

Extends and laterally flexes neck, elevates ribs

Iliocostalis thoracis

stabilizes thoracic vertebrae in extension

Iliocostalis lumborum

Extends vertebral column, depresses ribs

External intercostals

Elevates rib cage for normal inspiration

External and internal oblique

compresses abdominal wall, assists back muscles in trunk rotation and lateral flexion

Infraspinatus

lateral rotation of arm

Internal intercostals

depresses rib cage for expiration

Latissimus dorsi

prime mover of arm extension, adducts and medially rotates arm

Linea alba

area where rectus abdominis, external oblique, internal oblique, and transversus abdominis interlace

Pectoralis major

arm flexion, adducts and medially rotates arm

Pectoralis minor

elevates ribs, draws scapula down and medially

Rectus abdominis

flexes and rotates vertebral column, fix and depress ribs, stabilize pelvis

Rhomboid major

retraction of scapula

Serratus anterior

protract and hold scapula against chest wall, rotates scapula

Serratus posterior

elevates and depresses ribs

Supraspinatus

abducts arm

Teres major

extends, adducts, and medially rotates arm

Teres minor

lateral rotation at shoulder

Transversus abdominis

compresses abdominal contents

Trapezius

retraction, elevation, and depression of scapula; extends neck and stabilizes shoulder