Understanding Flexion-Intolerant Low Back Pain in Functional Fitness

Flexion-intolerant low back pain (FILBP) is a prevalent issue among individuals engaged in functional fitness activities, including CrossFit. This condition is characterized by discomfort or pain during movements that involve bending forward at the lumbar spine. Exercises such as deadlifts, kettlebell swings, rowing, toes-to-bar, burpees, and devil's presses, which require significant lumbar flexion, can exacerbate symptoms.

Mechanisms Behind Flexion Intolerance

The lumbar spine's intervertebral discs are particularly susceptible to flexion-related stress. Repeated or sustained forward bending increases pressure on the anterior portion of these discs, potentially leading to disc herniation or bulging. This can irritate adjacent nerve roots, resulting in pain that may radiate to the buttocks or legs, commonly known as sciatica. Individuals with FILBP often experience heightened discomfort during activities involving forward bending and may find relief in positions that promote lumbar extension. However, while stretches like the "prayer stretch" may provide temporary relief, they can potentially exacerbate the problem by repeatedly placing the lumbar spine in a flexed position, which may aggravate underlying issues over time.

Common lumbar extension exercises that may provide relief include the "cobra" pose, repeated cobra movements, and the backward phase of a Glute-Ham Developer (GHD) sit-up. These exercises encourage spinal extension, which can help alleviate pressure on affected discs and reduce pain.

Impact on Functional Fitness and CrossFit

Functional fitness and CrossFit routines frequently incorporate high-repetition, high-intensity movements involving lumbar flexion. For example, a typical workout might include a sequence of 21 kettlebell swings, 15 toes-to-bar, and 9 deadlifts performed in rapid succession. While this workout can be effective for increasing fitness in individuals without FILBP, it can place significant stress on the lumbar spine for those with this condition. When executed with improper form or under fatigue, such routines may provoke increased symptoms in the back or legs.

Conclusion

FILBP presents a significant challenge for individuals participating in functional fitness and CrossFit. Consulting with a physical therapist who understands weightlifting and CrossFit, and modifying workouts to reduce lumbar flexion, can be effective steps toward managing symptoms and maintaining fitness goals. Understanding the underlying mechanisms and recognizing the impact of specific movements on the lumbar spine are crucial steps toward effectively addressing this condition.

If you're experiencing any of these symptoms and cannot resolve them, give us a call to see how we can help