Florence Springer remembers she was waiting for a phone call to go shopping. When the phone rang, she rose to answer it. "I took two steps and there was nothing there," she said. She fell.

Until that moment six years ago, Florence Springer, then age 78, had led an active, mobile and independent life. The moment she fell, she says, "My life came to an end. Everything stopped." Her hip was broken, and her best efforts to resume a normal life style failed. Despite her injury, Mrs. Springer remains a lively and spirited woman, but she is a chair-ridden invalid now who had to give up her apartment, move in with her son and eventually go into a nursing home.

Mrs. Springer's experience is not unusual. Falls, a commonplace event for children and a nuisance for adults, are often a catastrophe for the elderly. Fractures resulting from falls and from weakened bone structures can in a matter of seconds cause a permanent and traumatic change in a person's life and are a major cause of invalidism and immobility.

Almost 200,000 persons a year over age 50 suffer hip fractures, with roughly 10 percent of those dying as a result. The total cost of these injuries is estimated to be in excess of $1 billion annually. Studies of nursing home populations suggest that roughly 8 percent of their residents are there because they have fractured their hips.

In addition, an estimated 15 million persons in the United States--about 75 percent of them women--suffer from osteoporosis, a bone-weakening condition that is one of the most frequent causes of hip fractures among the elderly.

What the figures cannot measure, however, is the psychological damage that results from a fracture--especially a hip fracture, one of the most common of such injuries.

"Anyone who's sustained a major fracture, particularly to a lower extremity, really lives in fear of that happening again," said Dr. Howard Levine, a Washington rheumatologist. "And many times you'll hear the statement, 'I don't exactly know how it happened. The next thing I knew I was on the ground and my hip was broken.' If you have no way of establishing what it was that led up to your hip fracture, you live in fear of the same thing happening again because you feel you have no control over it.

"Many times, these persons will become a cardiac cripple, disabled on an anticipatory basis, for fear that the same thing is going to happen again. Those people will begin to avoid places that have stairs and escalators, start sending other people out to do their shopping. They'll avoid theaters, they'll avoid crowds where they can be jostled."

Levine described a patient in her early 80s whom he had treated for arthritis, using cortisone. Despite her arthritis, Levine said, the woman was extremely active and independent, driving her own car and moving about on her own. Levine said the woman was "a hard-nosed, independent lady. If you tried to help her out of a chair, which she really needed because of her arthritis, she would jerk her arm away and tell you, 'I can do it myself.' "

About a year or two ago, however, the woman broke her osteoporosis-weakened hip while getting out of bed. She successfully underwent surgery and had her hip replaced, Levine said, and then received physical therapy. But the woman is "absolutely petrified of the same thing happening again," Levine said. Now she insists on being driven wherever she goes. When she visits her daughter, he said, she will do so only if her daughter agrees to meet her at the car.

"She has a phobia now," Levine said. "She's a sad, almost dithering sort of lady. She's mentally alert, but afraid."

The elderly are susceptible to falls for several reasons, according to Dr. Patience White, a rheumatologist at George Washington University Hospital. They have more trouble maintaining their balance than younger persons, for one thing, so they fall more often. And when they do fall, their reflexes are slower and they are less able to protect themselves.

Since it is the hips that end up absorbing many falls, they get damaged frequently. In many cases, fractures that appear to result from falls actually cause them, the bone having broken before the fall occurs. Wrists also are frequently fractured by the elderly in attempting to break their falls, but the consequences of a wrist fracture are far less serious than a hip fracture.

Fractures among the elderly are especially prevalent among women. The primary cause of these fractures is osteoporosis, which aggravates other factors making elderly women susceptible to fractures. Osteoporosis usually accounts for compression of the spinal cord in older women and men--giving them a stooped appearance--as the vertebrae become soft and are compressed from their normal square shape into rectangles.

As the body ages, it loses bone mass or bulk. Beginning at age 35 to 40, Men start losing about 3 percent of their bone mass a decade and women 8 percent, according to White.

Bone tissue contains two main components: a soft framework made of protein, and calcium salt deposits on this framework. The body naturally loses calcium and replaces it by absorbing it from food. A long-term deficiency in foods containing calcium--especially milk and other dairy products--can contribute to osteoporosis, which is essentially a deficiency of bone mass, and to osteomalacia, a deficiency in the calcium content of bones.

Coupled with the calcium deficiency that can produce osteoporosis is the decline in physical activity among the elderly. Bones, like muscles, thrive with use and atrophy without it. The more stress applied to a bone, according to Levine, the denser the bone becomes and the less chance of a fracture. "The woman who remains physically active is going to take a hedge against osteoporosis as opposed to the woman who remains sedentary," says Levine.

The woman or man who becomes bed-ridden increases, rather than decreases, the possibility of osteoporosis. Bones that are not stimulated through use give up their calcium to other sites in the body that are used. The bones of elderly patients take longer to mend.

A major cause of osteoporosis is the change in the body's hormonal balance. In menopause and old age, the body's production of the female hormone estrogen and the male hormone androgen decreases. These hormones are important in maintaining the body's calcium balance.

Dr. Joel Posner, medical director of the Philadelphia Geriatric Center, said that osteoporosis in many cases can be prevented and/or reversed by increasing the intake of calcium by drinking at least three glasses of milk a day and taking calcium supplements under a physician's supervision.

Posner said that he makes sure that "all my female post-menopausal patients and all my relatives who are post-menopausal . . . get 1,200 milligrams of calcium a day." Medical research indicates that the average woman of 45 gets only 450 to 500 milligrams a day. The result is a negative calcium balance of 40 milligrams a day and a bone loss of 1.5 percent annually.

Normal exposure to sunlight, a main source of Vitamin D for the body, also can help prevent or reverse osteoporosis. Vitamin D aids the body in absorbing calcium.

Osteoporosis also can be treated with estrogen. This treatment, however, involves serious side effects, including a heightened risk of cancer of the uterus lining.

Persons suffering from osteoporosis can experience seemingly spontaneous breaks from actions no more strenuous than turning over in bed, in an extreme case, and are more susceptible to breaks when they fall.

Rosa Belle Andert, 84, who now lives at Thomas House, a combined retirement home and nursing facility in Northwest Washington, broke her hip about 10 years ago when she lived in her own apartment. "I went to go to the refrigerator," she said, "and I slipped and fell. I just remember that I fell." Her right hip was broken and though she was able to walk again for some time with the aid of a walker, she has not been able to function normally since.

A fractured hip is not always the end of mobility and independence, however. A 76-year-old who broke her right hip four years ago, while walking in Georgetown, has resumed a normal, active life. This woman, who asked that her name not be used, was on crutches for five months and walked with a cane for another two after her fracture. She apparently does not suffer from osteoporosis.

But the woman also had the assistance of her husband to help her during the most difficult period of her injury. The woman's husband drove her to activities and picked her up, enabling her to maintain a busy schedule of volunteer activities.

Although she was forced for a time to give up swimming, she has resumed that activity as well. Since recovering from her broken hip, she also has started driving again, allowing her to be active and independent.

The key to her recovery may have been in her attitude to her injury and the way she approached the world afterwards. "I think that any sensible person uses a certain amount of caution," she said. "It would be more a matter of using prudent caution than going around with anxiety. It was not something I was anxious about. I mean, it happened, it was healing and it didn't interfere. You just took it as something unfortunate that's not going to stop you."