An Overview of Flat Back Syndrome

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Flat back syndrome is also called fixed sagittal imbalance. In this condition, the normal curve in your lower spine is reduced or absent. A major symptom is difficulty standing for long periods of time.

Flat back syndrome can be present at birth. It can also happen for other reasons, including:

  • Degeneration or trauma
  • Spinal surgery

Treatment often involves physical therapy, bracing, or surgery.

This article looks at flat back syndrome, its causes, and diagnosis. It also discusses treatment options.

Woman in plank pose outside
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Symptoms of Flat Back Syndrome

Your spine normally has two curves. Your lumbar spine in your lower back and your cervical spine in your neck curve inward. Your thoracic spine in your upper back curves outward. These curves are part of your spine's natural alignment. They help you balance and maintain your center of gravity.

When these curves are diminished, you can have trouble standing up straight. You may stoop forward, especially at the end of the day. You may even feel like you're falling forward. To stand up straight, you might have to flex your hips and knees and adjust your pelvis.

In a person with flat back syndrome, the lumbar spine doesn't have its natural curvature. This causes the head and neck to pitch forward, which can make it hard to walk and do day-to-day activities. You may feel tired from the strain of trying to stay balanced.

The body compensates for flat back syndrome by carrying the head and neck forward. This can cause strain and chronic pain in the neck, upper back, and shoulders.

Causes of Flat Back Syndrome

Some causes of flat back syndrome include:

Flat back syndrome can also happen after spine surgery. In the past, this was common after surgery to correct scoliosis, an abnormal curvature of the spine. The devices implanted during these surgeries could cause flat back syndrome, especially with age. Updated surgical techniques have reduced this complication.


Some people are born with flat back syndrome. For others, it develops over time as a result of a medical condition like arthritis.

Diagnosing Flat Back Syndrome

To begin, your doctor will ask your about your medical history, including any spine deformities or back surgery. You will also undergo a physical exam, including:

A gait exam assesses how well you walk. This is done because your gait might have changed to compensate for the loss of spinal curvature.

Finally, X-ray imaging will help your doctor see how your spine is aligned. Other possible sources of your symptoms will need to be considered before the diagnosis can be confirmed.


Your doctor will take a medical history and perform a series of physical exams. An X-ray can help confirm the diagnosis.

Treating Flat Back Syndrome

Treatment for flat back syndrome usually begins with exercise and physical therapy. This typically includes stretching and strengthening exercises to improve posture. The goal is to reverse the pattern of muscle imbalance that keeps the lower back flat.

Exercises to strengthen core, buttocks, back, neck, and rear shoulder muscles include:

A gentle hamstring stretch is a good way to improve the alignment of your lumbar spine. Hold the stretch for about 30 seconds at a time. Repeat three to five times once or twice a day.

Your physical therapist can recommend exercises and other forms of treatment. This may include bracing to provide better support.

Some patients may need surgical correction. There are a few options, including:

  • Polysegmental wedge osteotomy
  • Pedical subtraction osteotomy
  • Posterior vertebral column resection


Flat back syndrome is usually treated with exercises that strengthen the muscles in the neck, back, and core. In rare cases, surgery may be needed.


Flat back syndrome is caused by a loss of the curvature in your lower spine. It can be present at birth or it can happen as a result of surgery or a medical condition.

People with flat back syndrome carry their head and neck too far forward. This can cause pain and difficulty balancing.

Flat back syndrome can be diagnosed with a medical history, physical exam, and X-ray imaging. Treatment typically includes physical therapy and exercise, though sometimes surgery is necessary.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kim D, Menger RP. Spine sagittal balance. In: StatPearls [Internet]. Treasure Island, Fla: StatPearls Publishing; 2021.

  2. National Health Service. Common posture mistakes and fixes.

  3. Roussouly P, Nnadi C. Sagittal plane deformity: an overview of interpretation and management. Eur Spine J. 2010;19(11):1824–1836. doi:10.1007/s00586-010-1476-9

By Anne Asher, CPT
Anne Asher, ACE-certified personal trainer, health coach, and orthopedic exercise specialist, is a back and neck pain expert.