Severe Lower Back Pain When Sitting or Bending

Lower back pain can be an intermittent discomfort or a continuous ache. Sometimes, the pain may be particularly severe when you sit down, rise up from a chair, or straighten your back after bending forward.

While in most cases the underlying cause of the pain can be identified, sometimes back pain may be non-specific with no identifiable cause.¹Casser HR, Seddigh S, Rauschmann M. Acute Lumbar Back Pain. Dtsch Arztebl Int. 2016;113(13):223–234. doi:10.3238/arztebl.2016.0223

Here are a few possible causes for severe low back pain in such situations.

Axial back pain

Pain that is localized to the lower back is called axial back pain. This condition can be acute or chronic and causes one or more of the following symptoms²Förster M, Mahn F, Gockel U, et al. Axial low back pain: one painful area--many perceptions and mechanisms. PLoS One. 2013;8(7):e68273. Published 2013 Jul 2. doi:10.1371/journal.pone.0068273:

• Severe lower back pain upon slight movements
• Pain felt when external pressure is applied to the lower back
• A constant ache deep within the lower back

See Axial Back Pain: Most Common Low Back Pain

Axial back pain may be caused by various underlying causes. Degenerated discs, herniated discs, degenerated facet joints, and dysfunction of the sacroiliac joint are common mechanical pain generators of the lower back. The ligaments of the spinal canal and/or lumbar vertebrae or the weakening of spinal muscles can also cause axial back pain.³Vora AJ, Doerr KD, Wolfer LR. Functional Anatomy and Pathophysiology of Axial Low Back Pain: Disc, Posterior Elements, Sacroiliac Joint, and Associated Pain Generators. Physical Medicine and Rehabilitation Clinics of North America. 2010;21(4):679-709. doi:10.1016/j.pmr.2010.07.005

Read more about Causes of Lower Back Pain

If the lower back pain increases while seated, and typically improves after standing, it may indicate a herniated disc in the lumbar region (lower part of the spine).⁴Alamin TF, Agarwal V, Zagel A, Qeli A. The effect of standing vs. variants of the seated position on lumbar intersegmental angulation and spacing: a radiographic study of 20 asymptomatic subjects. J Spine Surg. 2018;4(3):509–515. doi:10.21037/jss.2018.08.03

See Lumbar Herniated Disc: What You Should Know

Increased activity of the trunk muscles

If you have chronic low back pain, it is possible that your trunk muscles are over-activated when you perform certain tasks. Common examples of such tasks include⁵Lima M, Ferreira AS, Reis FJJ, Paes V, Meziat-Filho N. Chronic low back pain and back muscle activity during functional tasks. Gait & Posture. 2018;61:250-256. doi:10.1016/j.gaitpost.2018.01.021:

• Bending forward to pick up or put down an object
• Sit and/or stand
• Climb stairs

The increase in muscle pain during these activities occurs due to an abnormal adaptation of these muscles to guard the spine. Certain groups of muscles may be activated more than others, causing pain while performing specific tasks.⁵Lima M, Ferreira AS, Reis FJJ, Paes V, Meziat-Filho N. Chronic low back pain and back muscle activity during functional tasks. Gait & Posture. 2018;61:250-256. doi:10.1016/j.gaitpost.2018.01.021

See Back Muscles and Low Back Pain

Coccydynia (tailbone pain)

Soreness or pain in the tailbone (coccyx) commonly occurs due to trauma and can become chronic and debilitating.⁶Lirette LS, Chaiban G, Tolba R, Eissa H. Coccydynia: an overview of the anatomy, etiology, and treatment of coccyx pain. Ochsner J. 2014;14(1):84–87. Typical symptoms include severe pain during one or more of the following actions⁷Foye PM. Coccydynia. Physical Medicine and Rehabilitation Clinics of North America. 2017;28(3):539-549. doi:10.1016/j.pmr.2017.03.006:

• Sitting down
• Leaning partly backward while sitting
• Sitting on hard surfaces
• Standing up from a seated posture

Coccydynia pain is abruptly relieved after standing up. Patients typically prefer to sit by leaning forward or lean onto one buttock or the other while sitting to avoid the tailbone pain.⁷Foye PM. Coccydynia. Physical Medicine and Rehabilitation Clinics of North America. 2017;28(3):539-549. doi:10.1016/j.pmr.2017.03.006

Sacral tumors

While rare, tumors or cancer in the sacrum (lower part of the spine) can cause pain while sitting and/or during the process of standing up. The most common type of tumor affecting this region is the sacral chondrosarcoma. The symptoms of this condition are vague, often causing a delay in diagnosis.⁸Pillai S, Govender S. Sacral chordoma : A review of literature. Journal of Orthopaedics. 2018;15(2):679-684. doi:10.1016/j.jor.2018.04.001

Early symptoms include⁸Pillai S, Govender S. Sacral chordoma : A review of literature. Journal of Orthopaedics. 2018;15(2):679-684. doi:10.1016/j.jor.2018.04.001:

• Lower back pain
• Pain while sitting

As the tumor increases in size, sciatica (radiating nerve pain in the leg), urinary tract infections, and/or loss of bowel and bladder functions may occur.⁸Pillai S, Govender S. Sacral chordoma : A review of literature. Journal of Orthopaedics. 2018;15(2):679-684. doi:10.1016/j.jor.2018.04.001

See Types of Spinal Tumors

Other examples of sacral tumors are giant cell tumor and plasmacytoma of the sacrum.⁸Pillai S, Govender S. Sacral chordoma : A review of literature. Journal of Orthopaedics. 2018;15(2):679-684. doi:10.1016/j.jor.2018.04.001

When to see a doctor

If you have lower back pain and/or severe pain during functional movements that is not relieved by self-care and medication, it is advised to seek medical attention. A doctor can help diagnose and treat the cause of your pain and also rule out serious conditions such as tumors, fractures, or infections of the spine.

See When Back Pain May Be a Medical Emergency

In case of non-specific back pain, treatment options typically follow several combinations of nonsurgical treatments such as physical and/or massage therapy, prescription or over the counter (OTC) medication, and/or injections to see what works best.

See Non-Surgical Treatments for Lower Back Pain

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Treatments for Lower Back Pain