On a family trip to the Grand Canyon three summers ago, my son Erik, who was hiking behind me, remarked: ''Mum, your right hip is higher than your left.''
''I know,'' I replied, promptly dismissing this observation.
But it returned to haunt me many months later, when I had two related realisations: My left trouser legs were all too long, and I had shrunk another inch.
Diagnosis: Adult-onset scoliosis, an asymmetrical curvature of the spine that, if unchecked, could eventually leave me even shorter and more crooked, disabled by an entrapped spinal nerve, and dependent on a walker to maintain my balance.
Determined to minimise further shrinkage and to avoid pain and nerve damage, I consulted a physiatrist who, after reviewing X-rays of my misshapen spine, said the muscles on my right side, where the spinal protrusion is, were overdeveloped relative to the left. He prescribed a yoga exercise _ a side plank _ to strengthen the muscles on the left and exert enough of a tug on my spine to keep it from protruding farther to the right. He suggested that the exercise might even straighten the curve somewhat.
I've been doing this exercise, along with two others suggested by a physical therapist, every day for the past eight months. The therapist also told me to have heel lifts put in or on all my left shoes to help even out my hips and shoulders. While it is too soon to say whether there has been a significant reduction of my spinal curve, it has definitely not worsened and, unless my mirror lies, I look less lopsided.
Although scoliosis is generally thought of as a problem of adolescents, who often require bracing or surgery to correct the curvature, the condition is actually far more prevalent in older adults. In a study by orthopaedists at Maimonides Medical Center in Brooklyn of 75 healthy volunteers older than age 60, 68% had spinal deformities that met the definition of scoliosis: a curvature deviating from the vertical by more than 10 degrees.
Previous studies had reported a prevalence of scoliosis in older adults of up to 32%. These reviews may have included adults who were younger than those in the Brooklyn study, whose average age was 70.5 and who had no pain or impairment related to their spinal condition.
Whichever is the real rate, the prevalence of scoliosis in adults is high and expected to increase as the population ages. The most common underlying cause of spinal deformities arising in midlife or later is the degeneration of the discs between vertebrae and sometimes of the vertebrae themselves.
Unlike scoliosis in youth, which afflicts many more girls than boys, adult-onset scoliosis affects men and women in roughly equal proportions. Some had scoliosis as children; it had stabilised, only to progress again gradually as advancing age took its toll on the spine. But the vast majority of adults with scoliosis had normal spines in their youth.
A misshapen body is the least serious consequence of scoliosis. It can result in disabling pain in the buttocks, back or legs, and neuropathy, a disruption of feeling and function when a spinal nerve is compressed between vertebrae. Neuropathy must be treated promptly to prevent nerve death and a permanent loss of function.
While there are no sure-fire ways to prevent all cases of adult scoliosis, certain conditions that are preventable increase the chances it will develop. One is being overweight or obese, and another is smoking. A third cause is a lack of physical fitness, resulting in weak core muscles.
Other risk factors include the wear-and-tear of osteoarthritis and osteoporosis, a thinning and weakening of the bones that can cause the vertebrae to break down and compress unevenly. People who undergo spinal surgery to remove tissue pressing on nerves sometimes develop spinal imbalance. A spinal injury that deforms vertebrae can also lead to scoliosis.
Typically, adults don't seek treatment for scoliosis until they develop symptoms, the most common of which are lower back pain, stiffness and numbness, cramping or shooting pain in the legs. Those affected often lean forward to try to relieve the pressure on affected nerves.
Others with scoliosis may lean forward because they lose the natural curve in their lower back. This compensating posture, in turn, can strain the muscles in the lower back and legs, causing undue fatigue and difficulty performing routine tasks.
Exercises that strengthen core muscles _ those of the abdomen, back and pelvis _ help to support the spine and can reduce the risk of developing scoliosis, as well as prevent or minimise its symptoms. Demonstrations of core exercises that can be done at home, with or without an exercise ball, are easily found online. I am a swimmer, and my physical therapist insisted that I add the backstroke to my daily workout in the water, both to further strengthen my core and to develop upper back and shoulder muscles that will keep me from becoming bent forward as I age.
I soon discovered that the backstroke is more challenging than freestyle, and in doing it for half of my 40-minute swim, I've lost weight as well as gotten stronger.
Most people who develop symptoms of scoliosis can be treated with over-the-counter pain medication and exercises to increase strength and flexibility. Bracing is not recommended for adult scoliosis because it can further weaken core muscles.
Surgical treatment is reserved for those with disabling symptoms not relieved by non-invasive remedies. Surgery often involves spinal fusion to relieve pressure on the affected nerves.
It is riskier in adults than in adolescents with scoliosis _ complication rates are higher and recovery is slower, according to the Scoliosis Research Society.
But progress is being made in developing less invasive measures, including the use of biologic substances that stimulate bone growth in degenerated vertebrae.