The Science of Sciatica
Sciatica describes pain along the sciatic nerve path, usually from compression or irritation at the spine level. The nerve can be affected by disc material, bone spurs, or tight muscles along its path. Similar to general low back pain, sciatica often involves disc dysfunction, but with the added complexity of nerve root compression or irritation. When the nerve is irritated, it can cause pain, numbness, or weakness anywhere along its path from the back to the foot. The location and type of symptoms help identify where the problem originates. In some cases, sciatica may occur alongside degenerative disc disease or spinal stenosis, requiring careful assessment to address all contributing factors.
Contributing Factors
Prolonged sitting is one of the biggest culprits I see with sciatica. When you sit, especially with poor posture, you increase the pressure on your lumbar discs by up to 40% compared to standing. This forward-slumped position narrows the spaces where nerves exit your spine, potentially compressing the nerve roots that form your sciatic nerve.
Poor lifting mechanics multiply the problem. When you bend at your waist with a rounded back instead of squatting down, you can increase disc pressure by 300%. Combined with lifting weight away from your body, this creates massive compressive and shearing forces on your lower spine. Repetitive bending, twisting, and lifting - especially first thing in the morning when your discs are most hydrated and vulnerable - sets up the perfect storm for disc problems.
Your movement patterns throughout the day matter tremendously. Tight hip flexors from prolonged sitting pull on your lower back, forcing your lumbar spine into excessive extension. Weak glutes fail to stabilize your pelvis during walking and stair climbing, placing extra demands on your spine. Even something as simple as how you get out of bed or your car can repeatedly stress the exact structures that are already irritated.