Back Pain During Pregnancy's

Mechanical instability in the lumbar spine (lower back) and pelvis commonly results in lower back pain in pregnant women. 

Causes  

• The lumbar spine undergoes compensatory lordosis—an increase in the reverse C-shaped curvature—which causes excess strain on the lumbar joints, muscles, ligaments, and discs.
• The psoas muscle in the hip, which stabilizes the spine and helps in hip and leg movements, is shortened due to the compensatory lordosis, exacerbating the lower back pain symptoms.

 Lower back pain symptoms may start at any time during pregnancy. These symptoms may feel like: 

• A dull ache or sharp, burning pain in the lower back area
• One-sided pain in the right or left area of the lower and/or mid-back
• Pain that radiates into the back of the thigh and leg, and sometimes into the foot (similar to sciatica)
• Foot drop, a condition characterized by the inability to lift the front part of the foot while walking.