Building bone density starts decades before osteoporosis is a concern. At the same time, it is never too late to start building bone density even if you have already been diagnosed with osteoporosis. Bone, just like any other tissue in the body, constantly undergoes a process of new cell growth and old cell breakdown. Different factors, generally lifestyle choices, change this ratio and may start to cause problems with bone formation. Osteoporosis does not impact all bones equally, but instead is an indicator that bones that have low density are not being stimulated to grow for a variety of reasons, like inadequate loading. Certain types of stress to the bone caused by movement and weight-bearing stimulate new growth. Bone takes about 10 years to completely turn over, so every 10 years you get a new skeleton!
Mechanics of Bone Growth
Mechanical deformation, like forces from gravity, ground reaction, and muscle contraction, stimulates bone growth and resorption. Muscles attach to our bones in order to move us around. This means bone responds to the movement of our muscles as well as the impact of bearing weight. When the muscle contracts and pulls on the bone, internal forces of the bone cause the bone tissue to resist this pulling action. In physics, this is called stress. Stress to the bone stimulates mechanical signaling within the bone, telling it to lay down extra calcium in the areas under stress. Putting the bone under stress causes positive change up to a certain point. Once the bone reaches stress that it cannot resist, failure of the bone results in one or more fractures. The more positive stress we create, the more the bone adapts and the higher the threshold for a fracture will be. The more we contract our muscles at increasing higher loads, the more bone growth we stimulate. Weight-bearing activity through the bone has the same effect.
Building Bone Density
Several factors determine bone density, including nutrition, hormones, and activity levels. While food choices and even certain medications help to improve bone density, movement is the most overlooked component of a bone density building program. When it comes to building bone density, not all exercise is created equal. For example, swimming might be a great exercise but does not provide enough impact for building healthy bones. The types of movement chosen for bone health are very important.
Body alignment matters for building bone density. Your skeleton requires full-weight bearing in order to maximize bone density, meaning our alignment needs to be vertical. Daily habits, like excessive amounts of time spent sitting in chairs, alter our alignment. Bone density is impacted by shoe choices, walking mechanics, and the types of exercises we choose to do. For example, wearing a heeled shoe forces the pelvis to push forward changing the way our feet, knees, and hips bear the weight of our torso. For every one degree of heel that is worn, there is one degree of spine, hip, and knee joint reaction (have we convinced everyone to ditch the heels yet?!). Standing with the pelvis pushed forward or our trunk leaning forward changes the weight-bearing forces to the bones.
Start building bone density today by working on body alignment, exploring different footwear options, and getting more walking into your day. We suggest starting with stretching, most importantly the calf stretch, and seeing a trained professional to assist you with walking mechanics and footwear choices. It is never too late or too early to start!