Osteopenia, or low bone mass affects approximately 34 million Americans every year. An additional ten million people have very low bone mass, or osteoporosis. While these conditions tend to be more prevalent in women, they can appear in both genders. Women, however, tend to lose bone mass earlier in life and at a faster frequency. In fact, women suffer an astounding 20 percent of bone mass loss in the first five to seven years following menopause. It goes without saying that a decrease in bone mass can result in some very unfortunate situations. For instance, we know that people tend to fall later in life, a time when their bone mass is at its lowest. This can lead to fractured bones such as a broken hip, a condition that results in significant disability and has a one-year mortality rate of about 24 percent.
The human body is amazing and ever-changing, as demonstrated by our bones. Our bones peak in overall mass between the ages of 17 and 30 years old. Then our bones enter into a maintenance stage where approximately the same amount of overall mass is present until around 50 years of age. From age 50 on however, there is rapid loss. We can use aerobic and resistance training methods to build and maintain bone mass early in life, but sometimes later in life that's not enough. If you're at risk or already diagnosed with bone loss, you should discussion treatment options with your primary care provider. Often times this will include calcium supplementation or hormone replacement therapy.
Our bones are constantly remodeling in response to stresses imposed on them. This principle, known as Wolff's Law was discovered in the late 19th century. Essentially it means that when bone is placed under stress, it grows bigger, and when it is not stressed it will become less dense and weaker. This concept is vital, because it helps to highlight the importance of weight bearing activities. While low-impact aerobic exercises like biking are great for your heart and lungs, they don't stimulate high levels of bone growth. Walking, jogging, or step aerobics, however, do generate higher levels of bone growth. Likewise, resistive strength training stimulates bone growth in a very positive way. There is also some evidence to suggest that use of a vibrating plate, a platform that moves under an individual's feet, can increase bone growth as well. As physical therapists, we use detailed examinations to determine the appropriate level of exercise for an individual and often prescribe a home exercise program to help them meet their goals.
In conclusion, it should be everyone's goal to increase bone mass as much as possible until it peaks around age 30. From there, practicing a healthy lifestyle including exercise can help to limit bone loss in mid-life. The switch in focus to preserving bone mass and limiting falls begins in later years. A physical therapist can be a helpful guide during every stage of this blueprint, and I encourage you to contact us with any questions or concerns you may have.