Torso Muscles

The torso or body trunk is the largest and central part of the human body, to which the neck and limbs are connected. It holds most of the major organs in the body, including the heart, lungs, intestines, liver, and sexual organs. In fact, the brain is the only major organ that is not located within the torso.

It houses some of the most vital muscles responsible for maintaining posture, supporting the spine, enabling breathing, and facilitating a wide range of movements. The torso muscles include both large, visible muscles, like the pectorals and abdominis muscles, as well as deep, stabilizing muscles that lie closer to the spine and organs, like the diaphragm and erector spinalis.

These muscles work together to provide strength, flexibility, and protection for internal systems, playing a crucial role in nearly every motion we make, from sitting upright to twisting, lifting, and even breathing.

List of Torso Muscles

Anatomically, the torso includes the following muscles based on the regions they are located in:

At the front:

• Thoracic or chest muscles
• Abdominal muscles
• Pelvic floor muscles
• Perineal muscles

At the back

• Back muscles

All these regions are interconnected, yet each contains its own functional and structural muscle groups that are impossible to list in one place. The following are the muscles that are structurally and functionally most important for the torso or trunk.

Muscles That Form the Anterior, Lateral, and Posterior Sides of the Torso

Here is a list of the primary muscles forming the front, sides, and back of the torso. These mainly involve the largest and often superficially located muscles of the chest, abdomen, and back.

Name	Part of Torso it Forms	Location in the Body
Pectoralis minor	Anterior torso	Chest
Intercostals	Anterior torso	Chest
— External Intercostals	–	–
— Internal Intercostals	–	–
— Innermost Intercostals	–	–
Transversus thoracis	Anterior torso	Chest
External oblique	Anterior and lateral torso	Abdomen
Internal oblique	Anterior and lateral torso	Abdomen
Transversus abdominis	Anterior and lateral torso	Abdomen
Rectus abdominis	Anterior torso	Abdomen
Pyramidalis	Anterior torso	Abdomen
Serratus anterior	Lateral torso	Chest
Pectoralis major	Lateral torso	Chest
Latissimus dorsi	Lateral, and posterior torso	Back
Trapezius	Posterior torso	Back
Rhomboid major	Posterior torso	Back
Rhomboid minor	Posterior torso	Back
Serratus posterior superior	Posterior torso	Back
Serratus posterior inferior	Posterior torso	Back
Erector spinae group	Posterior torso	Back
— Spinalis	–	–
— Longissimus	–	–
— Iliocostalis	–	–
Deltoid*	Posterior torso	Shoulder (upper arm)
Teres major*	Posterior torso	Shoulder (upper arm)
Teres minor*	Posterior torso	Shoulder (upper arm)

Primary Torso Movements and the Muscles Involved

Movement	Description	Muscles Involved
Flexion	Bending your torso forward, like when touching your toes	Rectus abdominis, internal obliques, external obliques
Extension	Arching your back or bending backward	Erector spinae group
Lateral Flexion	Bending your torso to the side, like reaching down your leg.#	Internal obliques, external obliques, quadratus lumborum, erector spinae
Rotation	Twisting your upper body to the side, like looking behind you	Internal obliques, external obliques, transversospinales group
Stabilization/Compression	Bracing your core to keep your torso steady, like during a plank	Rectus abdominis, external oblique, transversus abdominis, multifidus, pelvic floor muscles