Medicine for Osteoarthritis: What’s Hot, What’s Not

If you watch any television, then you know there are a variety of products for easing the pain of osteoarthritis (OA). OA causes the cartilage to wear away in the joint. Loss of joint cartilage usually results in painful symptoms and loss of motion. OA most commonly causes pain in the hip and knee joints. Each therapy has its place, but often there are side effects.

Acetaminophen (TylenolTM) is the number one drug of choice for OA. It doesn’t give complete relief of pain, but it works well for mild to moderate pain. There are some effects on the liver. Nonsteroidal anti-inflammatories (NSAIDs) all work about the same. Some are more toxic than others. The stomach and kidneys are affected the most.

Glucosamine and chondroitin sulfate are two supplements that are being studied. Both seem to help the joint while also relieving the pain. Side effects seem to be limited. Vitamins such as A, C, and E may protect the cartilage and nearby tissues. This is also under study.

Capsaicin, a topical cream made from hot chili peppers, can be used. It only gives short-term pain relief, so it must be used often. Some patients feel a burning sensation with this cream.

Injections into the arthritic joint have been used. Steroid injections have lost favor because of their side effects. These powerful anti-inflammatories are used only when other treatments have failed. Hyaluronic acid (HA) made from chickens can be injected into the knee. This helps increase the natural fluid in the joint. Using HA may delay the use of injected steroids or surgery.

Osteoarthritis can be treated with pain relievers, glucosamine and chondroitin, vitamins, creams, and injections. When these no longer work, surgery to replace the joint is an option. Joint replacement can reduce pain and improve function when other treatment fails.

Outpacing Pain in the Workplace

More and more workers in the United States and Canada are sitting for a long time at a computer. About two-thirds of the workforce in North America have jobs that require sitting for most of the work day. Studies have shown that long periods of time in front of a computer screen and sitting without moving result in muscle pain and problems.

One group is at great risk for these problems. People who work as directory assistance operators do not control their own rate or pace of work. Calls are controlled by the computer, and the screen flashes when calls are waiting. This is called electronic pacing. Electronic pacing sets up a conflict between the need to take exercise breaks and the need to keep up work.

Studies have shown that workplace exercise programs reduce muscle pain and physical discomfort. The benefits can be felt in as little time as one week. Researchers found that even with the employer’s approval, many workers still didn’t take the time to do the exercises. This is common when work is paced and workers feel pressured by time.

Employers, unions, and workers need to find ways to help workers stretch and exercise on the job. This will help reduce muscular and work-related physical problems. Two to four stretches lasting five to 10 seconds each should be done every hour. A stretch break of one to two minutes should be added once a day. For workers who are electronically paced, a computer program can be used that includes reminders and pauses to do these exercises.

Time and Attention Are Therapeutic

When you go to a clinic, what’s more important to you? Would you rather see the nurse, doctor, or therapist on time, or have enough time together for your care?

Health care providers find themselves working in a competitive market. Patients are customers, and their satisfaction is important. Physical therapists are concerned about this. Therapists know that a patient who is happy with the treatment is more likely to follow the treatment plan.

Research is being done to find out what patients need and want. Several different groups of physical therapists are testing patient surveys about this. One group asked 2,000 patients what was important to them. They used the information to develop a survey for patients in an outpatient physical therapy clinic.

The survey helped point out what factors are important in patient care. Patients were most satisfied when the therapist spent enough time with them and listened to them. Receiving a clear explanation of treatment is also important. They also found that the survey could be used by other outpatient clinics to measure patient satisfaction.

The medical world is seeing that quality of life is an important part of treatment. Quality of life includes getting the care patients want and need. When this need is met, patients are more satisfied, and they achieve better treatment results.

Physical Fitness Tests That Stand the Test of Time

As the population ages, doctors are increasingly concerned about promoting physical fitness among older adults. Physical fitness improves cardiovascular health. It also improves older adults’ ability to do tasks of daily living. Physical fitness can prevent falls and lower the risk of fractures from falls. It may even reduce nursing home admissions.

Doctors need ways to test physical fitness in older adults. Such tests need to be safe for older adults to do. They also need to have some real relationship to health and function.

A group of doctors in Finland tried out a series of physical fitness tests on a large group of men and women between the ages of 55 and 79. In order to make the tests safe, some participants were excluded due to health problems. Participants who got past the health screening did tests of balance, flexibility, strength, and cardiovascular fitness. These tests included a one-legged stand; side, back, and leg bends; a one-legged squat; short and long walking tests; and a stair climb. 

Could the participants safely do the tests? The older participants got, the less likely it was that they could safely do the tests. For women, the main limitation was bone and joint health. For men, cardiovascular health was also a problem. Even so, about 85 percent of the participants could safely do the tests. Participants were most likely to be excluded from the back extension test (raising the upper body from a bent-over position) and the one-legged squat. Women in the oldest age group were often excluded from the one-legged stand and the long walk. Only one injury occurred during the tests.

Did the tests actually measure health and function? Yes. Test performance was strongly related to participants’ ratings of their health and ability to do daily activities.

Obesity was linked to poorer function for both men and women. This suggests that weight control may help older adults do activities of daily living. For women, obesity was also linked to poorer health. In general, the ability to do daily activities was a better gauge of fitness than participants’ ratings of their own health.

A series of physical fitness tests can safely be done by middle-aged and older adults as long as participants are screened for health problems first. Walking, climbing stairs, standing from a seated position, and back extension are good measures of health and function. These tests can be used in programs to improve physical fitness among older adults.

Take Action against Colon Cancer

Being physically active on a regular basis lowers the risk of colon cancer. But does adding fruits and vegetables or increasing fiber in the diet give any extra protection? A group of researchers at two cancer centers in the United States are studying this question.

The researchers looked at more than just diet. They also looked at factors such as calcium, cigarette smoking, body fat, and age. Activity patterns at home, work, and during leisure time were also measured. All of these factors were used to see what effect they had on colon cancer.

Physical activity and colon cancer are strongly linked. The risk of colon cancer for any adult (man or woman) can be cut by 40 percent just with high levels of physical activity. This must be done on a regular basis over a long period of time.

Men who are overweight have a higher risk of colon cancer. This is especially true if they are not physically active. For people who are more active, cigarette smoking increases the risk of colon cancer. Anyone who is active but has a family history of colon cancer is at greater risk when compared to active adults without a family history.

Scientists still don’t know how or why physical activity lowers the risk of colon cancer. There are many ways suggested for how this happens. It seems that physical activity can affect the benefits from other risk factors. More studies will look at how physical activity acts together with diet and lifestyle factors.

Where Is the Fat?

Obesity is so common it is now the biggest health problem in the United States. The health risk is not only due to the amount of fat, but also where the fat is located. Studies have shown that fat in the upper body or trunk and fat in the abdominal area are the most serious problems. This type of fat adds to the risk of diabetes, heart disease, and death. Fat in the legs has little or no risk to health.

Researchers are looking for ways to reduce fat, especially in the abdomen. Studies of aerobic exercise show that it reduces abdominal fat in both men and women. A new study using resistance training show that this may be another good choice for women.

After 25 weeks of resistive exercises (three times a week for 45 minutes), abdominal fat decreased in older women. Older men lost fat throughout the body, but not in the abdomen. The exercises used were not just for the abdomen but also included arm and leg exercises.

Further study is needed to find out why men lost fat in other parts of the body but not the abdomen. Only one section of the abdomen was measured, so it could be that men lost fat in other parts of the abdomen that were not measured.

Physical Therapists Get Hurt at Work, Too

Many people have work-related pain or discomfort. This is called a work-related musculoskeletal disorder (WMSD). Often, physical therapists (PTs) treat people with WMSDs. Sometimes the PTs develop WMSDs too!

It seems that the PT’s knowledge and expertise would prevent WMSDs. This is not always the case. Several studies report a high rate of WMSDs among therapists. In fact, one in six Australian therapists changed jobs after a WMSD. By definition, WMSD is work-related and lasts three or more days. Therapists have neck, back, shoulder, wrist, hand, and thumb pain of this type.

PTs have a unique problem. They highly value hard work and being caring and helpful. These very traits put them at risk for injury themselves. Many therapists feel pressured by themselves and by others to work, even when they are in pain or injured. They want to be caring and hardworking even when it hurts their own health.

Knowledge and experience don’t always prevent work-related injuries. This is shown by the high number of physical therapists with WMSDs.

Information from several studies in other work settings points out the need to change the job, not the worker. In other words, jobs can be made safer when hazards are identified and changed, rather than simply making workers do the same tasks in new ways. Further studies are needed to find ways to change the hazardous parts of the therapist’s job. Controlling or reducing risks for WMSDs is the first step in this process.

No Time for Exercise? Take the Stairs!

Everyone knows that exercise does the body good. But for many people, it’s hard to find the time. For others, exercise equipment and gym memberships may be too costly. Researchers are putting an end to these excuses. All the exercise equipment you need may be right in your home or office building. Instead of taking the elevator, just take the stairs!

How good of a workout do you really get from going up and down stairs? How many calories do you burn? These questions were of special interest to researchers in Singapore, where nearly 90 percent of the population lives in high-rise buildings.

The researchers monitored men and women going up and down the stairs of an 11-story building (180 steps). Participants were timed going up and down the stairs at a brisk, constant pace. Their heart rate and oxygen uptake were monitored to see how hard they were working. 

Results showed that stair-climbing meets the guidelines set by the American College of Sports Medicine (ACSM) for exercise intensity. This was particularly true for going up stairs. The physical intensity while climbing rises for the first minute or two, then levels off. The intensity of going up stairs is similar to that of jogging (ten km/hour). Going down stairs, a milder intensity is set much earlier and is similar to brisk walking (four km/hour).

In general, the faster participants went up stairs, the more their breathing and heart rate increased. Exercise intensity varied somewhat based on gender and body mass. Men got up the stairs faster than women, but their heart rates didn’t go up as much. Heavier people breathed more rapidly during the climb.

What is the energy cost of going up and down stairs? In other words, how many calories do you burn? The researchers estimate that each step takes .16 calories. Going up 180 steps burns nearly 20 calories, and going down burns about nine calories. To meet the ACSM guidelines for weight loss and body fat reduction, you would need to go up and down these stairs seven times (25 minutes), four times a week.

Stair-climbing is a convenient way to exercise. In terms of heart rate and oxygen uptake, stair-climbing can be used to meet the minimum requirements for cardiorespiratory benefits.

Crunch Time Enlarges Lifetime

How many sit-ups can you do? Maybe you think this is an outdated measure of fitness. Perhaps. Yet new research indicates your sit-up performance may predict your chances of living longer.

A new study of physical fitness and the risk of dying was done in Canada. Researchers measured muscular fitness in more than 8,000 people. They measured sit-ups, pushups, grip strength, and flexibility. The results were close to a similar study of muscular strength and death in Japanese men and women.

Some parts of physical fitness can be used to predict the risk of death (mortality). One example is grip strength. The lower the grip strength measured, the more predictable the chance of earlier death. Grip strength is a good measure of overall body strength.

The main finding in this study had to do with sit-ups. How many sit-ups an adult can do is linked to mortality for both men and women. The fewer the sit-ups performed, the greater the risk of death. Flexibility and push-ups were not predictive of death. There are several reasons why abdominal muscle strength may be a better measure of mortality.

Having strong abdominal muscles is a sign of an active and independent life. Muscle strength also shows there is enough muscle mass (number and size of active muscle fibers) for good health. How the body uses glucose (sugar) is important in preventing diabetes, a deadly disease for some people. The muscles are a key part of the processing of glucose. The more the amount of active muscle is present, the better the body can use glucose.

The payoff for staying active and doing regular exercise is more than a trim waistline. It now appears that muscle fitness is a key part of maintaining health and life.

Tick-Tock Affects Doc Talk

In our fast-paced society, some people worry that quality, person-to-person communication has fallen by the wayside. This goes for doctors and patients, too. Medical advances mean doctors have more to share with patients. But the time doctors can spend with patients is less because of managed care, outpatient surgery, and shorter hospital stays.

Recently, the American Academy of Orthopaedic Surgeons did a survey to see how orthopedic surgeons communicated with their patients. The surgeons surveyed thought they were good listeners. However, patients thought the surgeons were less caring and used more technical words than their regular doctors.

Good communication starts with the first doctor visit. Information is shared, a relationship builds, and the patient is given choices for treatment. Doctors who have good communication skills use open-ended questions, versus questions that can be answered with “yes” or “no.” They also practice active listening. These techniques allow doctors to really understand the needs of their patients.

Good communication has many benefits. Patients are more satisfied when they have been able to express their concerns. They make more informed decisions and follow their treatment plans. They have better results and make fewer malpractice claims. Good communication also reduces costs of care. Patients who are educated by their doctors have shorter hospital stays and fewer complications, and they use less pain medication.

Although communication is important, doctors don’t get much training in this area in medical school. Researchers have developed workshops to improve doctors’ skills in this area. Workshops involve role-playing, videotapes, and open discussions. After just eight hours of workshop training, doctors improve their communication skills. And the results seem to last.

To improve relationships between doctors and patients, communication skills should be taught in medical school and tested on certifying exams. Doctors should also be encouraged to go to special workshops to enhance their skills in this area. The American Academy of Orthopaedic Surgeons will continue to work toward these goals so that patients can get the best possible care.

Disabled Workers Get a Lift Back to Work

If you’ve never been injured on the job, the term Functional Capacity Evaluation (FCE) may not mean much. But for the worker who is disabled and can’t do the work required by the job, FCE is very important. FCE is the examination that measures a person’s level of function compared to the demands of the job. FCE tries to answer the question: Does this person have the ability to do the job safely?

Eleven million people in the United States receive disability benefits. The cost of disability in the United States was seven billion dollars in 1998. Spending that much money means some tests must be used to decide who is disabled and who can return to work. There isn’t a single instrument that measures all areas of work ability. Different tests measure different work-related functions.

What determines whether a person can go back to work? Do lifting ability and grip strength show when a person can safely return to work? Recent research suggests that the more weight a person can lift from the floor to the waist, the more likely it is that the worker will go back to work. Grip strength isn’t related to return to work, however. The longer a worker is away from the job, the less likely he or she is to return to work. Men are less likely to return to work than women.

FCE measures work-related abilities. The ability to lift objects from the floor to waist level is a valuable measure of when a person can return to work. Members of the health-care team use the results to help injured workers get back to work activities that are safe.

Death by Orthopedic Surgery: Are You at Risk?

What are your chances of dying in the hospital after orthopedic surgery? This is a grim question. But anyone having major surgery of any kind faces some risk of death. Fortunately, death is rare after surgery on bones, muscles, ligaments, or other soft tissues.

The biggest risk factors for death after orthopedic surgery are age (over 70 years) and hip fracture. Risk also goes up in the presence of kidney or lung disease. Cancer and other diseases put patients at greater risk. For example, research shows that pneumonia is the number one cause of death after orthopedic surgery.

Special care can be given when any risk factors are present. For example, doctors may order closer follow-up after surgery. Antibiotics may be given before surgery to help prevent infection. Less than one percent of patients die after orthopedic surgery. Even so, doctors evaluate each patient to know whether special measures will be needed before or after surgery.

The Internet Provides a New Pathway to Health Care

The Internet is changing the way Americans seek health care. In the past, doctors were the gatekeepers to medical information. With a Web-full of health information, the Internet has ushered in a new model of health care called “patient choice.” Patients are looking for medical information and advice on their own, before seeing a doctor. The Internet allows patients to be much more involved with their own care.

Patients use the Internet to get information on many medical subjects. Patients often want doctors to recommend Web sites to help explain medical conditions. If the Internet is the wave of the future, then the information provided there must be accurate, well written, and unbiased. Patients need protection from companies that advertise products or services that haven’t proven effective.

Patients who get accurate and reliable information on the Internet can make better decisions about their own care. But poor medical information on the Internet makes the doctor’s job harder. It’s important to help patients get the right information. Directing patients to trustworthy Web sites for medical information saves time and increases patient satisfaction.

Physical Therapy or Surgery for Bone Problem? MRI Breaks the Tie

Osteochondritis dissecans (OCD) is a special kind of bone problem that usually affects older children and young adults. With OCD, there is a loss of blood supply to a small portion of bone. That piece of bone gets separated from the main bone and begins to die. The body tries to heal itself by filling in the space between the main bone (called the parent bone) and the separated bone. This sometimes helps bring blood back to the area.

OCD can be treated with physical therapy or surgery. But which treatment is best? Most studies show that results are the same with either approach. Surgery is usually saved for older patients with severe pain, swelling, and loss of motion.

Magnetic resonance imaging (MRI) can help doctors decide how to treat OCD. MRI shows details that can’t be seen with X-rays. MRI clearly shows the location and stage of OCD. It also shows the condition of the bone fragment, fill-in tissue, and parent bone.

Recently, MRI was used to evaluate the results of either physical therapy or surgery for young patients (under age 16) with OCD. Results showed that these patients did better with physical therapy.

MRI helps doctors examine the condition of bone and decide which treatment to use for OCD. Surgery is best for patients with a higher stage of OCD. In the higher stage, there isn’t enough fill-in tissue between the separated bone and the parent bone. The separated bone is loose and may become detatched.

Forget the Piggy Bank: Kids Need to Bank More Bone

Children need to deposit plenty of calcium in their bone banks. This is especially important for later years when osteoporosis or “brittle bones” can become a problem. Bone strength and resistance to fracture depend on the amount of bone mineral in the bones. Building up enough bone by early adulthood is the number-one key to preventing osteoporosis in adults. Having enough bone mineral density also prevents bone fractures in children and teenagers.

Childhood and adolescence are the two most important times for building bone mass. Kids need a lot of vitamin D, calcium, and phosphorus as their bones grow. However, many kids do not get even the minimum amount of these nutrients in their diets. This is becoming a national problem. In fact, the National Health Institute (NIH) has said that low calcium intake is now a major health concern.

New technology may help researchers suggest ways to deal with this problem. Dual-energy X-ray absorptiometry (DEXA) is now able to measure bone density. This helps researchers understand how bone is made and stored. Researchers want to measure healthy children of all ages to determine normal bone measurements. This is called the baseline and can be used to compare bone measurements among children. That way, it will be easier to tell which kids have low bone density and are at risk for fracture or osteoporosis.

Researchers are raising the following questions to help find ways to combat the problem of low bone density among children and adolescents:


  • Does taking calcium supplements increase bone density?

  • Does calcium supplementation need to happen before a certain age?

  • Does calcium improve the amount of bone mineral in all bones or just certain ones?

  • Are there other steps that can be taken to help build bones and prevent bone loss before adulthood?

  • Are boys different from girls in the timing and amount of calcium needed?

Time and future research are needed to answer these questions. For now, we know that many children in the U.S. are not getting enough calcium in their diets. Further discoveries will make it possible for doctors to tell which children are at risk for bone loss and fracture. Building bone during childhood is essential to kids’ health, both now and in the future.

Pop Quiz! How Do Your Muscles Wear Your Years?

In the last 100 years, major gains have been made in the life expectancy of adults in the United States. Today, life expectancy is 78.5 years for women, compared to 48 years at the turn of the last century. Life expectancy is 71.8 years for men. These numbers are still on the rise.

The “graying of America” has led to research on aging and its effects on the body. One area of particular interest is the muscular system. Are age-related changes in the muscles inevitable, or can these be prevented? Researchers have studied the effects of aging on the muscles. Now they are looking for ways to combat these changes.

How well do you know the effects of aging on your muscles? Take the following quiz.

True or false? Aging affects muscle power and muscle endurance at the same rate.

False. Aging affects muscle power more quickly. Muscle power refers to the kind of short bursts used for quick movements or to lift objects. Endurance is measured in how long the muscles can work.

Research shows that muscle strength decreases faster than endurance. The muscles’ capacity to perform activities that require power and endurance is still present throughout adulthood. But only those adults who train and remain in good health can keep up both power and endurance.

True or false? Muscles lose fibers with age whether or not they are exercised.

Trick question! The jury is still out on this one. Many studies show a loss of fast-twitch muscle fibers with aging. Other studies do not agree.

True or false? The effects of aging on muscles are the same for men and women.

True. The patterns of change are the same for both sexes. Lifting or activities requiring power show a pattern of sharp decline after age 30. The fastest loss of muscle power occurs during the fourth decade (31-40 years). There is a gradual, slow loss of power in adults as they continue to age.

For activities requiring muscle endurance, there is a rapid rise in muscle performance until around age 25, then a gradual decline until age 55. After age 55, there is a faster rate of decline in muscle function.

True or false? Adults over 30 can offset loss in muscle strength with exercises.

True. Some form of regular resistance training can offset age-related loss of muscle strength. Inactivity is the main reason people lose muscle tissue. Many studies show major improvements in muscle function with proper conditioning.

Pass the Peas, Please

Researchers keep coming up with more reasons to stock up on vegetables. Now they’re suggesting you use bags of frozen vegetables to treat pain and injury. Research shows that applying a bag of frozen peas can be just as effective as using one of the cold packs sold in stores–maybe even more effective.

Cold has long been used to treat pain and injury. This treatment is known as cryotherapy. Cryotherapy can reduce pain, muscle spasm, and inflammation.

Research shows that, compared to gel packs, frozen peas have a superior cooling effect on skin, even after 20 minutes. Frozen peas are solid but hold a lot of water. The water must melt before the peas warm up. This means the peas stay cold (32° F, the freezing point of water) until all the water has melted.

In comparison, gel packs begin to warm up as soon as they are placed on the body. Gel packs in this study didn’t lower skin temperature enough to give full pain relief, reduce muscle spasm, or slow down nerve messages.

Frozen gel packs may look official. But frozen peas cost less and provide greater relief–and they definitely taste better. So the next time you have pain or injury, reach for the peas.

Water-Based Exercise Makes a Big Splash among Older Women

Water aerobics and other water-based exercise have become very popular among older adults. Water makes it possible to exercise without the effects of gravity or the force of the ground putting pressure on the joints. This is especially helpful for adults with orthopedic problems. Water-based exercise is recommended for people with medical conditions of all kinds. It is a way to get the resistance, aerobic, and flexibility training recommended by the American College of Sports Medicine for good health.

Research has shown that walking in waist-deep or chest-deep water builds heart and lung fitness. Water-based exercise leads to improved use of oxygen. It lowers cholesterol levels. It also improves kidney and hormone function. This kind of exercise increases the strength of muscles in the chest, arms, legs, and low back. Agility and flexibility also improve. All of these effects may mean fewer falls and injuries for older adults.

Researchers evaluated the benefits of water-based exercise for Japanese women ages 60 to 75. A group of women participated in a 12-week water-exercise program three days a week. These women were compared to women who did not do this program. The benefits of water-based exercise were clear.

Water-based exercise is a safe way to be physically active for all ages–especially older women. This type of exercise can improve heart and lung fitness, and increase muscle strength. It can also reduce body fat and total cholesterol. Water-based exercise offers an easy way to combine strength, aerobic, and flexibility training for the best overall health benefit.

The Geography of Anesthesia: Local, Regional, or General

There are three types of anesthesia used for surgery. Local anesthesia numbs a small area, patch of skin, or body part. Regional anesthesia locks feeling in just one area, such as the shoulder or one side of the hip. General anesthesia puts the person to sleep, unaware of what’s happening.

Certain operations have always required general anesthesia and an overnight stay in the hospital to control pain. Improvements in surgical technique have allowed more of these surgeries to be done under regional anesthesia. The person goes home the same day, unless severe pain requires further hospitalization.

Doctors want and need to know which anesthesia is best. They measure this by how long the patient stays in the recovery room, how much pain medication is used, and how long it is before the patient goes home. Complications such as blood loss or accidental injection of anesthesia into the lung, blood vessel, or spine are also considered.

One surgeon reviewed his own records to compare the results of shoulder surgery using regional versus general anesthesia. There were no differences in the amount of time patients stayed in the hospital. There were no differences in how long patients were in surgery or under anesthesia. The main difference was in how much pain patients had after surgery. Less pain was reported in the group that received regional anesthesia. This also meant less pain medication was used in the first four hours after surgery.

Health care providers are always looking for ways to reduce the costs of surgery. Avoiding an overnight stay in the hospital is one way to do this. Less time in surgery, less blood loss, less pain medication, and a shorter recovery time are also ways to decrease medical costs. Regional anesthesia is now being used with success for total hip replacement, shoulder repair, hysterectomy, and removal of the prostate.

Taking Muscle Training to the Moon

Ever wonder how astronauts keep their muscles strong during long flights into space? It’s a question scientists have been grappling with. Aerobic exercise keeps astronauts fit, but it doesn’t help them maintain muscle size and strength in the absence of gravity. Over time, the effects of this muscle “unloading” are similar to what happens after long periods of bed rest. The muscles shrink and become weak. Scientists want to know whether resistance training might help and, if so, how much astronauts need to do to maintain their muscles in space.

Thirty-two young, healthy men were divided into two groups. Half of them had one of their legs suspended in a harness for 21 days. This was to mimic the unloading or weightlessness that happens in space. The other subjects were allowed to walk around as usual.

Half of the subjects in each group did a muscle training program every three days (six sessions total). The other subjects did no special training. The muscle training program included knee extension exercises, in which the leg was bent and straightened, and exercises pointing the toes toward the sole of the foot. The training program took about 20 minutes and worked the thigh and calf muscles to exhaustion.

Did muscle training make a difference? Results showed that, while the training program didn’t help subjects build muscle, it did keep them from losing muscle during 21 days of muscle unloading. It also helped them maintain healthy nerve and muscle function.

Subjects who didn’t do the training program during muscle unloading lost seven percent of leg muscle. Their strength with muscle tightening (flexing the muscle without moving the leg) went down 17 percent. The strength of their active contractions (flexing the muscle while moving the leg) also went down quite a bit, especially at slower speeds. In contrast, muscle size and strength either stayed the same or improved slightly for those in training.

A program of muscle contractions done every third day prevented loss of muscle size and strength during muscle unloading. The program involved fewer contractions over a longer period of time than those used in previous studies. However, this program was still effective in maintaining muscle. More studies are needed to determine the least amount of muscle training astronauts can do during space travel and still stay strong.