Lower back pain when walking can happen when the muscles, joints, discs, or nerves in the lower spine are irritated by movement. In many cases, the body changes the way it walks to protect the painful area, and that can make the lower back feel even more strained.
Walking-related lower back pain may also be linked to stiffness in the lower back and pelvis, which can make the muscles work harder with each step. Sometimes the problem is not only in the back itself, since changes in the hips or knees can affect posture and walking and place extra stress on the lower spine.
Another possible cause is pressure on the nerves in the lower spine, which may happen with conditions such as spinal stenosis or sciatica. When this happens, the pain may get worse with walking or standing and may come with tingling, numbness, weakness, or pain that spreads into the buttocks or legs.
A medical evaluation is important if the pain lasts more than a few weeks, gets worse, or happens with leg weakness, numbness, or trouble walking. The most appropriate specialists are a family doctor, orthopedic specialist, or spine specialist. Self-medication should be avoided, especially when the pain is persistent or severe.