August 21, 2026
Lower back pain that worsens with bending backward and improves with bending forward can sometimes point to a lesser-known condition called Baastrup’s disease, in which adjacent spinous processes, the bony projections at the back of each vertebra, come into contact with one another and become a source of chronic pain.
While it is not as commonly discussed as conditions like disc herniation or spinal stenosis, Baastrup’s disease is an important consideration for patients with a specific pattern of back pain that has not responded to typical treatments.
Baastrup’s disease, also sometimes called kissing spine syndrome, occurs when the spinous processes of adjacent vertebrae become abnormally close together and begin to rub or press against one another, typically in the lower back. Over time, this repeated contact can lead to inflammation, the formation of a fluid-filled sac called a bursa between the affected spinous processes, and degenerative changes in the bone itself.
The condition is most commonly seen at the lower lumbar levels, where the natural curve of the spine already brings the spinous processes closer together than in other regions.
Several factors can contribute to the development of Baastrup’s disease, including age-related disc degeneration, which causes the disc space to narrow and brings adjacent vertebrae closer together, exaggerated lumbar lordosis, or an increased inward curve of the lower back, and repetitive extension movements that involve bending backward.
Because these changes tend to accumulate over time, Baastrup’s disease is more commonly diagnosed in older adults, though it can occur in younger patients with significant lumbar lordosis or a history of repetitive back extension activities.
The hallmark symptom pattern of Baastrup’s disease is midline lower back pain that worsens with spinal extension, such as standing up straight, arching the back, or lying on the stomach, and improves with spinal flexion, such as bending forward or sitting in a slightly hunched position. Patients often notice that certain activities requiring sustained backward bending, such as looking up at a high shelf or certain yoga poses, reliably reproduce their pain.
This directional pattern, worse with extension and better with flexion, can be a helpful clue that distinguishes Baastrup’s disease from other causes of lower back pain that may follow a different pattern.
Diagnosis typically begins with a detailed history focusing on the specific movements that worsen and improve a patient’s pain, followed by a physical examination that may reproduce symptoms with spinal extension and identify tenderness directly over the affected spinous processes. Imaging, particularly MRI, can confirm the diagnosis by showing the characteristic close approximation of adjacent spinous processes, along with associated findings like bursa formation, bone marrow edema, or degenerative changes at the affected level.
Because these imaging findings can sometimes be present without causing symptoms, correlating the imaging with the patient’s specific symptom pattern is an important part of confirming that Baastrup’s disease is truly the source of a patient’s pain.
Conservative treatment is typically the first approach for Baastrup’s disease and often includes physical therapy focused on flexion-based exercises and core strengthening, activity modification to reduce repetitive spinal extension, and anti-inflammatory medications to address pain and inflammation.
For patients who do not respond adequately to these conservative measures, targeted injections of corticosteroid and local anesthetic into the affected interspinous space can provide both diagnostic confirmation and therapeutic relief. In cases that remain resistant to conservative treatment, surgical options such as removal of the affected bursa or a portion of the spinous processes may be considered, though surgery is generally reserved for more severe or persistent cases.
Patients diagnosed with Baastrup’s disease often find that understanding their specific pain pattern, worse with extension and better with flexion, helps them make practical adjustments to daily activities that reduce symptom flares. Simple changes, such as avoiding prolonged standing with an arched back or modifying sleep positions to reduce spinal extension, can meaningfully reduce discomfort for many patients.
Because this condition is less well known than other causes of back pain, patients who suspect they may have this pattern of symptoms should feel comfortable specifically asking their physician about Baastrup’s disease as a potential diagnosis if their symptoms fit this distinctive pattern.
Baastrup’s disease is often overlooked, but the right diagnosis can finally explain pain that hasn’t responded to other treatments. Call (866) 467-1770 to describe your symptoms to our team, or Request a Consultation Online to get evaluated.