Standing tall

Content provided by the Faculty of the Harvard Medical School

Standing tall

Exercises can help with the bad posture and osteoporosis that cause us to stoop and lose height as we get older.

With chronological addition comes some anatomical and physiological subtraction. As we age, we experience decrements in everything from hair and hearing to memory and muscle.

Height loss is also on the list. Starting at about age 40, people typically lose about half an inch each decade, and the decline usually accelerates after the 70th birthday. The phenomenon has been documented by researchers. The Baltimore Longitudinal Study of Aging is a well-known investigation that included roughly 2,000 people. The men in the study lost, on average, about two inches of height between ages 30 and 80, and the women, about three (see chart below).

Causes

Osteoporosis. As we get older, our bones become less dense, more brittle, and therefore more likely to fracture. This loss of bone tissue is called osteoporosis. The skeleton of a typical 70-year-old is about a third lighter than the typical 40-year-old's because of osteoporosis. Older women are particularly susceptible because of the drop-off in estrogen levels during menopause. Estrogen blocks resorption, the process by which calcium is released from bone into the bloodstream.

Inching downward Adults start losing height in their 30s because of poor posture and osteoporosis.

When a hip or wrist bone weakened by osteoporosis breaks, it's usually the kind of crack we have in mind when we picture a broken bone. But fractures of osteoporotic vertebrae, those knobby bones that make up our spine, are different. The bone crumples like a cardboard box that has had too much weight put on it.

It's called a wedge fracture when just one side of the vertebra collapses (see illustration, "Bent backs," below). Wedge fractures occur most often in the vertebrae in the thoracic (pronounced tho-RAS-ick) region of the spine, which is between the bottom of your neck and the upper part of the small of your back. Sometimes the whole vertebra gives way. This type of fracture occurs most often in the lumbar region that forms the forward curve of the small of your back.

Most of these vertebral fractures don't cause any pain or other symptoms and are discovered incidentally in a chest or abdominal x-ray.

You may lose a smidgen of height because the vertebrae themselves become a bit smaller vertically. More important, though, are vertebral fractures. Even a mild stoop in middle age may be a sign of vertebral fractures, and a bad one in older age almost certainly is. A prominent hump in the upper back (insensitively nicknamed a widow's, or dowager's, hump) is usually the result of wedge fractures in the vertebrae of the thoracic spine.

Bad posture. Some doctors and researchers believe that vertebral fractures have been overrated as a cause of height loss and kyphosis (pronounced kie-FOE-sis), the medical term for being hunched over. Dr. Harold Rosen, an osteoporosis expert at Harvard-affiliated Beth Israel Deaconess Medical Center in Boston, points to studies that have shown that only about 30% of kyphosis can be explained by vertebral fractures.

An exercise for improving your posture Lie flat on your stomach and relax your shoulders and back (top).By lifting your shoulders off the ground, you'll strengthen the muscles in your back, which can help improve posture (bottom).

It's hard to say what's behind the other 70%, but a big share of it may simply be bad posture. Some of us acquired a tendency to slouch in our teens that never quite went away. And if you spend a lot of time in front of a computer, you may notice how your back bends toward the video monitor and your shoulders roll forward. You're also contending with back muscles, like all muscles, getting weaker simply because of age. Bad posture begets more bad posture, because ligaments get stretched and muscles get trained to be in a bent- over position. Flabby abdominal muscles don't help. Hard "abs" can help your posture by counteracting tired back muscles.

Other causes. If a younger person loses height, it can be the first sign of scoliosis, abnormal curvature of the spine. Connective tissue disorders such as Marfan's and Ehlers-Danlos syndromes can cause a hunched back and therefore height loss.

Consequences

For many people, losing a little bit of height is no big deal. Compared with the other challenges of getting older — and handling them with grace — it can be pretty trivial. The strapping young grandchildren you're so proud of will seem that much taller if you're looking up at them from an inch or two further down.

There may be another silver lining. If you're hunched over, the abdomen and its internal contents get squeezed into less vertical space. As a result, you may think you've gained a lot of weight because you're bulging out in the middle and no longer have much of a waist. In reality, it's because you're stooped over.

On the other hand, severe kyphosis can cause all sorts of problems. It may affect your breathing because the lungs don't have enough room to expand. You may also be more likely to fall and break a hip or another bone because your center of gravity is shifted forward. And, no surprise, neck and back pain are often a problem.

Bent backs

Solutions

Improving your posture. You can do some simple exercises that will strengthen certain back muscles so you can stand up a little bit straighter. One of Dr. Rosen's favorites involves lying on your stomach and then lifting your head and shoulders for several seconds (see "An exercise for improving your posture," above). Slightly more strenuous is the "Superman" version that involves stretching your arms out in front of you instead of keeping them at your side. Sit-ups or crunches, a modified sit-up that involves contracting your stomach muscles, will strengthen your abdomen.

For overall muscle control as well as posture and balance improvement, many people swear by yoga or tai chi, a form of Chinese martial arts that has been described as moving yoga.

You can do these preventive exercises on your own if you are healthy. A little willpower, not a prescription, is all that's needed to get started. But if you're older, have osteoporosis, or both, it's a good idea to talk to a doctor before you get started on an exercise program. The wrong exercises could do more harm than good.

Researchers at the Mayo Clinic have experimented with a device they call the weighted kypho-orthosis. It looks like a little backpack. Small weights inside are supposed to pull people back a little bit, improving their balance and counteracting their hunched-over posture. The Mayo group has reported good results in short-term studies in which people wore the device while doing exercises and for short spells during the day.

Although they may sound simple enough, these devices shouldn't be purchased over the counter. They need to be properly fitted and supervision by a physician is important.

Strengthening your bones. The other way to limit height loss is to counteract the effect of osteoporosis on bone — and on the vertebrae in particular. The single best way to do that is to stay as active as you can. Innumerable studies have shown that weight-bearing exercise stimulates the creation of bone tissue.

There's even some evidence that exercise will translate into less height loss. A study based on data collected by the Belgium Ministry of the Interior and published in the medical journal Gerontology showed that people who exercised regularly — especially after age 40 — lost less height than those who didn't. The Mayo Clinic researchers have reported that stronger back muscles from exercises targeted for the back reduces vertebral fractures in postmenopausal women.

Canadian researchers have studied the effect of an exercise program on older women who already have vertebral fractures. Interestingly, the exercise didn't improve the bone density of the vertebrae, but it did seem to help preserve the shape of the bones.

Getting enough calcium and vitamin D is also important. How much is enough? If you're older than 50, the recommendation for daily calcium intake as of 2005 is 1,200 milligrams.

Doctors are changing their minds about vitamin D as the evidence of its benefits piles up. Those benefits seem to go well beyond just increased bone strength and may include improved balance. The recommended daily amount is 400 IU (International Units) for people ages 51 to 70, and 600 IU for those 71 and over. Some Harvard experts now believe that we may need at least 1,000 IU daily to protect ourselves against osteoporotic fractures.

A middle-of-the-road approach is to start taking a multivitamin. Most contain 400 IU of vitamin D. Milk, vitamin-fortified breakfast cereals, and coldwater fish (mackerel, salmon, sardines) can add another couple of hundred IU to your daily total. Your skin makes vitamin D when sunlight hits it, so stepping outside for a little bit on a sunny day is another way to get more of the vitamin into your system.

Last updated:	September 05, 2008