Get to know your lower back

Your lower back, or lumbar spine, is made up of five bones called vertebrae. They are the largest vertebrae in your spine, increasing in size from upper most to bottom, with the fifth at the base of your spine the largest of all. Its large size reflects the fact that it bears all of your weight from above as well as some tremendous forces generated from below, particularly by your powerful thigh and buttock muscles when you stand, walk and run. With these forces acting on it all day long, little wonder this is the most frequent site of all musculoskeletal pain, accounting for about 40-50% of cases.

Lying between each vertebra are flexible discs that act as shock absorbing cushions and allow movement between your vertebrae. Your discs also increase in size from top to bottom also reflecting the high levels of compression they must withstand.

In a neutral position, your lumbar spine naturally curves forwards so that your weight is evenly distributed throughout your vertebra and discs. This arch provides greater biomechanical stability and is essential for your upright posture. Your lumbar arch is sculptured by forces it experienced during crawling and walking and is not fully developed until the age of around eight years old.

Your lumbar spine is surrounded and affected by the largest and most powerful muscles in your body. More muscle mass is found at the base of your spine than any other part of your spine, again reflecting your lower backs’ high workload. From above, muscles extending down your entire spine, your ribs and even as far away as your shoulder place pressure on your lower back. A myriad of muscles interconnecting the vertebrae themselves also place significant pressure on your spine.

The greatest forces acting on your back are voluntary muscular contractions, that is, you have control of the most influential factor determining the health of your back. Looking at what these muscles are doing often provide vital clues as to how you are overloading your back.