The back consists of large, complex muscles that support your trunk and spine. There are many types of back muscles, and they are all essential, helping you walk, bend, twist, and hold your body upright. Unfortunately, the muscles in your back are also prone to injury, and back pain is one of the most common reasons people go to see their doctor.
Knowing about the different muscles in your back, how they work, and what you can do to strengthen them will help keep this critical muscle group healthy.
What Are Back Muscles?
Back muscles are skeletal muscles made up of tiny elastic fibers bound tightly together. They are part of the musculoskeletal system, which includes your bones, tendons, ligaments, cartilage, joints, muscles, and tissue — all working together to allow you to move.
Where Are Your Back Muscles Located?
There are many muscles in your back. They start slightly below your skull, cover your shoulders, and extend across the back and down to your upper hips. Many back muscles also connect to your ribs, the bones that support your spine, your shoulder blades, and your neck.
How Many Back Muscles Are There?
There are a total of 40 muscles in the back, consisting of 20 muscle pairs. This number can vary slightly depending on which muscles you count, though. For example, the serratus posterior superior and the serratus posterior inferior are two back muscles that are also key to helping you breathe, so they can also be counted as accessory or respiratory muscles.
What’s the Function of Back Muscles?
All back muscles fall into two primary groups: extrinsic and intrinsic. Intrinsic muscles are found deeper inside the body while extrinsic muscles are more external, and their movements are noticeable. These external muscles are further divided into two sub-groups, creating three main categories of back muscles:
Superficial muscles. These are in the extrinsic group and the first thing that comes to mind when people think of their back muscles. Superficial muscles support shoulder and neck movements, and four major muscles fall into this group:
- Latissimus dorsi (lats) — the largest muscle in the upper body, which runs from the shoulders to the lower back and supports extending and rotating your arms and shoulders.
- Levator scapulae — a small muscle that runs from the side of your neck to the scapula, or shoulder blade, which helps you raise your shoulders.
- Rhomboids — these muscles connect your scapula to the spine and help you bring your shoulders inward.
- Trapezius (traps) — these extend from the neck to the lower back in a V shape and allow you to move, raise your arms, and stand up straight.
Intermediate muscles. Two muscles make up the second extrinsic group. They connect to the ribs and spine and play a critical role in breathing. These two sets of intermediate muscles support your rib cage as your lungs expand and depress when you breathe:
- Serratus posterior superior — helps you breathe in
- Serratus posterior inferior — helps you breathe out
Superficial and intermediate muscles are also sometimes called immigrant muscles. This is because they were initially muscles that belonged to the arms and legs but moved to the back during the development of the fetus.
Intrinsic muscles. Intrinsic muscles are considered the only true back muscles. They are well-developed, large muscles that fuse with the bones that support your spine. Intrinsic muscles help you maintain your posture, bend, rotate your body, or flex your back.
Intrinsic muscles are divided into three categories, making up many smaller, interconnected muscles. The prominent intrinsic muscle groups include:
- Erector spinae — a large group of muscles arranged in three columns around the spine.
- Splenius muscles — found between your upper back and neck
- Transversospinal — muscles lining the upper spine
Signs Something Could Be Wrong With Your Back Muscles
Different things can cause your back muscles to hurt. They can sprain (or twist) if you pull them in an awkward movement or exercise. Muscles can also strain or tear when there is too much pressure on them or you stretch them too far.
Traumatic injury — for example, while playing sports or during a car accident — is a typical cause of severe muscle strain. Other causes can include not getting enough rest between activities, trying to hastily recover from a quick movement (like loss of balance), or lifting heavy objects.
Factors such as age, weight, and fitness level can also contribute to various back injuries. Signs that something could be wrong with your back muscles include:
- Bruising on the muscles
- Decreased mobility
- Limited range of motion
- Numbness in your back
- Pain and stiffness in your back
- Spasms (often very painful)
- Weakness in your muscles
Around 90% of adults will have back pain at one point in their lives. In some cases, the pain results from a mild strain and will go away after a few days of rest. If you’re experiencing any persisting back or muscle pain symptoms, talk to your doctor immediately to find out about treatment options.
How to Strengthen the Back Muscles
The muscles in your back are fundamental to everyday life. Considering the importance of back muscles to movement and posture, keeping them strong and healthy is a good idea.
Core exercises can target your back and strengthen the muscles in these areas to help prevent injury. Activities like pilates and yoga are two good examples, but many other exercises can also work your back muscles, including:
- Cables exercises
- Rowing (machine or suspended)
Even if you don’t exercise, there are a few other things you can keep in mind about taking care of your back muscles:
- Flexibility — Stretching and yoga can help keep your back flexible and relax your tight muscles.
- Lifting — Remember to always lift with your legs, keep items close to your body, and avoid lifting extremely heavy objects.
- Warming-up — Make sure to always warm up before doing anything strenuous.
- Weight — Conditions such as obesity, where you carry a lot of extra weight, can also contribute to pain in your back muscles.