Most of us know very little about our bones- they are hidden and not painful until we break one!

So let’s start with some anatomical facts and bone up (get the facts) on bones:

• At birth we have 300 immature bones; some of these join up; adults have 206 bones.
• The human hand has 27 bones; the face has 14.
• The longest bone in the body is the femur (thigh bone) which is about 1/4 of your height.
• Did you know that humans and giraffes have the same number of bones in their necks?

During our lifetime, our bones are in a continual cycle of breaking down and rebuilding. Bone strength represents the integration of bone density and bone quality. Most women will reach their 90% of their bone mass by the age of 18 and their peak bone mass by the age of 30 which emphasizes the importance of bone growth in childhood and adolescence through active and healthy lifestyles. As we age, and especially with hormonal changes associated post-menopause, the living bone tissue reabsorbs at a higher rate than rebuilding.

Bone thinning is classified as osteopenia or osteoporosis. Osteopenia, the less severe of bone weakening, is defined as having between -1 and -2.5 standard deviation of bone mineral density. Osteoporosis, the more severe of bone weakening, is diagnosed as having bone mineral density greater than -2.5 from the standard deviation. The stronger bones we have, the less likely we will fracture in a traumatic incident.

Physical activity can modify bone strength. When gravitation or muscle pull produces strain on the skeleton that is greater than optimal strain, bone formation occurs. In conjunction to other types of interventions, bone loss can be slowed and sometimes reversed. The improvements from exercise are likely from increased bone density and lessened endocrotial bone loss, not an increase in bone size. Women who engaged in a combination of exercise types had an average 3.2% less bone loss at the spine and 1.03% less bone loss at the hip than those who did not exercise.

Consider the following to protect your bones:

• Assessment of footwear and/or orthotics and adjustments if necessary.
• Review food intake with a doctor/nutritionist to check if you have the essentials for strong bones.
• Assessment of the load, type and intensity of your exercise program.
• Medical check-up to rule out other potential causes (like thyroid disease or medications that may cause bone loss).
• Don’t smoke and keep alcohol and caffeine intake to a minimum (these substances may lower bone density).

Written by: Reshma Rathod, PT