Fitness Corner
Fall 2002
Osteoporosis:
The Silent Crippler
How strong are you?
Article by The Army Physical Fitness Research Institute 

Osteoporosis is a debilitating disease, often called "the silent disease", as the mechanism of the disease has no symptoms. Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures of the hip, spine, and wrist.¹

The most common causes of osteoporosis range from physical inactivity, old age, malnutrition in the form of insufficient calcium intake, and low or depleted hormone levels as seen in estrogen-depleted postmenopausal women.

According to the National Institutes of Health (NIH), 10 million people have osteoporosis and another 18 million have low bone mass indicating the potential for osteoporotic conditions. This is a dreadfully debilitating disease that is largely preventable.

The purpose and organization of the skeleton is threefold and reveals the importance of bone strength. The primary purposes of the skeleton are:

• To provide support for loads against gravity and to aid in locomotion by providing sites for muscular attachment
• To provide a protective barrier for vital organs and bone marrow
• To serve as a mineral reservoir able to support blood levels of calcium and phosphorous when required. ²

Bones are dynamic, living tissue and are constantly rebuilding or remodeling. This remodeling is a dynamic process of breakdown and renewal, thereby maintaining the mechanical integrity of the bone by replacing fatigue-damaged older bone with new bone.

Reproductive hormones, calcium intake and mechanical loading are the three primary factors influencing and regulating bone remodeling.

1. The National Osteoporosis Foundation and The National Institutes of Health.
2. The American College of Sports Medicine. (2000) ACSM Guidelines for Exercise Testing and Prescription. Lippincott, Williams & Wilkins. Philadelphia, PA. Pp 288-293