Your back is a balanced network of bones, ligaments, muscles and nerves. All of these work together to balance and bear the weight of your body and the loads you carry.
Your spine has a series of curves — in your neck, upper back and lower back. These curves help absorb the impact of day-to-day living.
Any number of factors may contribute to lower back pain, including poor muscle tone, excess weight — especially around your middle — and improper or heavy lifting. In addition, poor posture and sitting or standing in one position for a long time puts extra stress on your back.
Among the causes of back pain:
Muscle strains. Strained muscles, tendons or ligaments or inflamed joints may cause pain along your spine.
Spasms. Muscle spasm is a common response to injury. The spasm is designed to immobilize the painful area and prevent further damage.
Osteoarthritis. This degenerative joint condition affects nearly everyone past age 60. Overloading, injury and aging can slowly cause deterioration of cartilage, the protective tissue that covers the surface of the joints of your vertebrae.