Understanding what lies beneath is key to your injury prevention and for continuing to run healthily and happily

Words: Dr Juliet McGrattan

As women runners, having an awareness of our bone health can help us avoid injuries. However, there’s more to bone health than you might imagine. Our current lifestyle can have a direct impact on our bones in later life, so it’s vital that we become informed and take simple steps to protect our bones and our future.

Anatomy lesson

The bony skeleton of the body is an engineering masterpiece. There are 206 bones in the adult body; they are strong, yet light and allow our bodies to move freely. Bones are made largely of collagen, a structural protein, and a mineral called calcium phosphate which adds strength. A rich network of blood vessels runs through and around bones to supply their needs and joints are supported by ligaments and activated by muscles. There are five different categories of bone in the body and they’re classified according to their shape:

■ Long bones – femur (thigh bone) and humerus (upper arm bone). Finger bones and metatarsals in the feet fall into this category because, even though they’re small, they’re longer than they are wide.

■ Short bones – square-shaped bones in the wrist and foot.

■ Flat bones – the skull and the shoulder blade.

■ Irregular bones – odd shapes like the vertebrae (back bones) or the jaw.

■ Sesamoid bones – these are embedded into tendons such as the patella (knee cap).

Bones contain different amounts of compact and cancellous bone tissue. Compact bone is the hard outer shell of bones and makes up around 80 per cent of our bone mass. Cancellous bone is the softer, spongier bone inside. It’s the air spaces in cancellous bone that make the skeleton so light. Vertebrae (back bones) have a small amount of compact bone and lots of cancellous bone whereas the long bones have more compact bone and less cancellous, making them stronger and more rigid.

How bones work

Bones do far more than just provide a skeleton to hang the rest of our body on. They are living tissues that have many different roles in the body including:

■ Enabling us to move. From tiny movements like pressing the button on our watch to running and jumping over roots, bones make it all possible.

There are 206 bones in the adult body which are strong yet light and allow our bodies to move freely

■ Protecting our internal organs. Ribs protect our heart and lungs, our pelvis protects our uterus and bladder, and our skull bones protect our brains.

■ Making blood cells. Bones are filled with bone marrow and red marrow makes over a million red blood cells every second. It also makes platelets for blood clotting and white blood cells to support our immune system.