Musculoskeletal problems weigh down postmenopausal women

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November 2006 Biomechanics Magazine

http://www.biomech.com/showArticle.jhtml?articleID=193700300

Musculoskeletal problems weigh down postmenopausal women

Hormonal changes may increase the risk of musculoskeletal injuries

in postmenopausal women.

By: Lori Rochelle Roniger

Otherwise healthy postmenopausal women are at increased risk of

musculoskeletal problems but no one's quite sure why. Biomechanics

practitioners are investigating whether strength training or other

exercise performed after menopause or preventively by younger women,

hormone replacement therapy, or other treatments can lower this risk.

While the increased risk of osteoporosis and osteoarthritis in older

women is old news, intensive research continues on exercise and the

risks and benefits of HRT and other medications, like raloxifene, to

combat these problems. But there has been less research conducted on

the increased risks of other musculoskeletal problems that women

face from the time of perimenopause-the period, ranging from months

to years, when hormonal levels start to change presaging the

cessation of menstruation-and beyond. These musculoskeletal problems

include Colles' fracture, adhesive capsulitis, osteoarthritis of the

basilar joint of the thumb, and carpal tunnel syndrome.

The hormonal fluctuations that women experience at menopause may be

responsible for a reduction in their physical strength and other

musculoskeletal changes. Some biomechanics researchers are

investigating such ways as specific exercise programs and

pharmaceutical solutions to prevent these problems.

However, the nonbiomechanical problems that have been associated

with HRT, such as increased risk of breast cancer and stroke, have

reduced funding available for research and prompted investigators to

direct attention toward nonpharmaceutical treatments.

Some of the work now being conducted involves research on how

specific exercise protocols may help women in their 40s, 50s, and

older stay strong and healthy and avoid the musculoskeletal problems

that have affected the women who came before them.

Research lacking

When C. Rich, PhD, PT, director of women's health physical

therapy at Bader Physical Therapy in Norway, ME, and editor-in-chief

of the Journal of Women's Health Physical Therapy set out to develop

her presentation on " Menopause and Musculoskeletal Problems: Aches,

Pains, and a Case for Prevention " for the American Physical Therapy

Association Combined Sections Meeting in February, she knew

anecdotally from her patients, acquaintances, and personal

experience that around menopause women reported an increased level

of musculoskeletal complaints, including fractures and joint pain.

" I thought it would be a relatively easy presentation, " said Rich,

who was previously a professor of physical therapy at the University

of New England in Portland, ME.

The frequency with which older women had presented in her practice

with adhesive capsulitis had set her project in motion.

Approximately 70% of adhesive capsulitis cases occur in women, with

the incidence increasing in those over age 40.

However, Rich found that research on musculoskeletal problems in

older women, explanations for their occurrences, and methods for

their prevention were relatively sparse in the medical literature.

Preparing for her presentation morphed into a larger project than

she had expected.

Rich collected information demonstrating that a number of

musculoskeletal problems, including rotator cuff impingement along

with the conditions listed above, affect women significantly more

than men. For example, women experience Colles' fracture seven times

more frequently than men and osteoarthritis of the basilar joint of

the thumb at least 10 times as often. A diagnosis of Colles'

fracture triples a woman's risk of hip fracture. And carpal tunnel

syndrome affects 11% of women but only 3.5% of men.

Musculoskeletal problems

The musculoskeletal problems, aches, and pains that tend to plague

women after menopause could be related to a drop in levels of

collagen in ligaments and other soft tissues, according to

indications in Rich's research.

A study published in the American Journal of Public Health in 1982

examined Colles' fracture risk among adult residents of Rochester,

MN, over a 30-year period. The researchers found that the fracture

incidence among women increased more than sixfold between the ages

of 35 to 39 and 60 to 64 and then flattened out, with lower rates

and less of a rise with age in men. The drop-off in estrogen levels

at menopause is thought to account for women's increased Colles'

fracture risk, Rich said.

In women older than 60, osteoporosis may be a causal factor in

Colles' fracture incidence. Following a wrist fracture women may

need to be screened for osteoporosis, according to a Colles'

fracture fact sheet from the American Academy of Orthopaedic

Surgeons. However, osteoporosis appears not to completely explain

women's risk for the fracture. A study published in the European

Journal of Internal Medicine in December 2005 measured bone mineral

density in postmenopausal women with Colles' fracture and controls

and found similar values in the two groups.

Carpal tunnel syndrome also increases in older women, seeing its

greatest occurrence in women over the age of 55, Rich said. Its

occurrence is associated with menopause, hysterectomy, pregnancy,

obesity, physical inactivity, and decreased wrist depth-to-width

ratio. Hormonal and physical attributes of women may make them more

susceptible to carpal tunnel syndrome, according to a review article

published in Clinical Orthopedics and Related Research in March 2000

written by Lynn Newport, MD, an associate professor of hand and

upper extremity surgery at the University of Connecticut in

Farmington.

Rich reports that osteoarthritis of the basilar joint of the thumb

is found in an astounding 50% to 75% of postmenopausal Caucasian

women, and that its overall incidence is 10 to 20 times greater in

women than in men.

Adhesive capsulitis, which typically restricts shoulder movement and

causes pain, is more common after age 40. An inflammatory condition

whose trigger is unknown, Rich reported in her presentation that

adhesive capsulitis could be connected to changes in hormone levels

or some autoimmune factor.

Rich likes to reference a study on strength relative to total body

weight and lean body weight in college-age men and women that was

conducted by Jack Wilmore, PhD, currently professor emeritus of

health and kinesiology at Texas A & M University in College Station.

Published in Medicine and Science in Sports in 1974, his research

demonstrated that while men had greater absolute upper and lower

body strength than women, the amount that women could leg press

relative to their body weight was relatively similar to what men

could do (14.74 versus 15.44) and the amount they could leg press

relative to lean body weight was actually greater than what men

could do (19.12 versus 17.62). This compared to a ratio of two-arm

curl maximum to body weight of 1.38 in men and 0.85 in women and

grip strength of 0.74 in men and 0.57 in women.

It could be that women's relative upper body weakness plays a role

in their comparatively greater incidence of certain upper body

musculoskeletal problems following menopause.

The hormone connection

Menopause, with its declining estrogen levels, may accentuate the

tendency of women to have relatively less upper body strength

compared to lower body strength, according to Rich. Some of the

musculoskeletal problems that occur more frequently in women around

menopause than in men at around the same age may be due to loss of

connective tissue strength that women experience then.

Before studies associating HRT with an increased risk of certain

medical problems were published, researchers like Gianni F.

Maddalozzo, PhD, an instructor at the Bone Research Laboratory at

Oregon State University in Corvallis, were receiving funding for

studies on HRT. However support for such research has waned.

Maddalozzo conducted a nonrandomized study that examined the changes

over one year in bone mass, lean mass, fat mass, upper and lower

body muscle strength, and lower body power in 126 active

postmenopausal women who had experienced menopause within the

previous three years. Their average age was 51. Sixty-seven of them

were already taking estrogen at the start of the study and continued

to do so, and the other 59 were not using hormone therapy.

Maddalozzo found statistically significant differences in bone

density changes between the two groups.

" Women not on estrogen lost more bone than women on estrogen, "

Maddalozzo said.

Lumbar spine bone mineral density dropped by 1% in the nonestrogen

group but held steady in the estrogen users, the trochanter lost 2%

of its BMD in the nonestrogen subjects but increased by 1% in the

estrogen group, and total hip BMD was virtually unchanged in the

estrogen group but decreased by 1% in the nonestrogen group. No

other significant differences between the groups were found by the

researchers. Femoral neck bone density showed a slight but

significant decrease in both groups. The study results were

published in the July/August 2004 issue of Menopause: The Journal of

The North American Menopause Society.

Other research has confirmed that hormonal changes at menopause

affect women's strength. British researchers reported in the journal

Clinical Science in 1999 the results of a double-blind, placebo-

controlled study in which women five to 15 years past menopause who

took hormones experienced a 15% increase in adductor pollicis muscle

maximal voluntary force compared to the control group after one year.

Menopause boot camp

While Maddalozzo certainly finds the potential benefits of HRT to be

intriguing, he also respects the need to avoid its potential adverse

effects. Given that, he wholeheartedly endorses exercise promotion.

" Maybe it is time to focus more attention on what we know does

work, " he concluded in his Menopause study. " Individuals who are

physically active have repeatedly been shown to have greater muscle

mass and strength and lower fat mass than nonexercisers. Thus,

developing strategies to get and keep individuals active may provide

greater public health benefits at a moderate cost versus a

pharmaceutical solution. "

Maddalozzo has submitted for publication an article on the results

of another study he conducted in which he randomly assigned 120

postmenopausal women to one of four groups: resistance training,

resistance training plus HRT, HRT only, and no resistance training

or HRT. The subjects not in the resistance training groups were

instructed to continue their regular physical activity routines,

which included such things as walking, gardening, swimming, aerobics

classes, or no exercise, but not to begin any weight training

programs. None of the subjects was involved in weight training at

the beginning of the study.

The resistance training used in the study involved performing squats

and dead lifts, which both place forces on the spine, two times per

week for one year. Participants did a warm-up set and three regular

sets for each exercise and stretched at the beginning and end of the

workout. The warm-up set was performed at 50% of the subject's one-

repetition maximum. The first set was designed to have subjects lift

to failure on the thirteenth repetition (that is, they would

complete 12 repetitions), the second set on the eleventh repetition,

and the third set on the ninth repetition.

After one year, bone mass at the spine increased by 0.4% in the

subjects in the resistance training group and 0.7% in the HRT and

resistance training group while the two nontraining groups lost bone

mass: the hormone therapy group was down 0.7% and the group that

didn't train or take hormones lost 3.6%. There was no statistical

difference between the two resistance training groups, but there was

a statistical difference between the training groups and the

nontraining groups, as well as between the group that took hormones

but not did strength train and the group that did not take hormones

or train.

" Hormone replacement therapy slowed bone loss but did not prevent

it, " Maddalozzo said. " We saw significant increases in lean muscle

with exercise two times a week and huge increases in upper and lower

body strength. "

He added that none of the subjects dropped out of the study because

they did not want to perform the exercises.

Women need to be prepared for menopause, Rich said, since we know

that these changes are coming, just like women are encouraged to

focus on achieving peak bone mass in their late 20s and 30s. Women

as young as their 20s and 30s should receive instruction from

physical therapists on performing exercises designed to strengthen

their upper bodies, she recommended.

" Specific exercises should be taught to them way before menopause, "

she said.

For example, Rich recommends exercises specific to rotator cuff

muscle strengthening like the empty-can exercise, which targets the

supraspinatus muscle. The empty-can involves lifting the arms at a

45 degrees angle from the body up until around shoulder height with

the palms facing downward, as if holding an empty can. She also

promotes stretching and aerobic exercise as preventive activities.

Prescription: exercise

Why so many women suffer from musculoskeletal problems following

menopause remains a mystery. Perhaps it's due to some factor that

hasn't been studied much yet. For example, a study published in the

journal Cell in April reported that high levels of follicle-

stimulating hormone, which is elevated approaching menopause, caused

bone loss. The study was conducted on mice, but it highlights the

fact that there remains much we may not know about how menopause,

hormonal changes, and aging affect the musculoskeletal health of

women.

For now, exercise appears to be the clear prescription for women

prior to menopause and following it, particularly upper body

strengthening activities. Getting the word out to practitioners and

women is key, as is figuring out how to motivate more women to

engage in strength training exercises.

Additional studies can tell us more about the most effective

exercise programs and, perhaps most important, how to get women to

participate in them in order to avoid-or at least postpone-

musculoskeletal decline.