News Category: Knee

A new study shows seniors over age 90 are helped by a total knee replacement (TKR). The pain relief and increased mobility these patients get makes it worth the effort. Most patients live more than five years after receiving the new knee joint.

Doctors at the Mayo Clinic in Rochester, Minnesota, followed 51 TKRs in adults ages 90 to 102 years old. Most were getting their first knee replacement. A few were having a second surgery to revise a failed first TKR. It’s likely that as more and more people live longer, TKRs put in at age 70 will need revision or replacement by the time the patient reaches 90.

Problems during and after the operation are a concern in this group. In this study, the rate of complications was 41 percent for first-time TKRs. Many problems were linked to medical conditions already present. The most common problems were high blood pressure, diabetes, or bleeding ulcers. Patients getting a previous TKR repaired or replaced didn’t have any complications.

Results from the operation are also important. The authors report a high rate of patient satisfaction. Everyone reported relief from pain. Three-fourths of the patients could walk without a limp or only a slight limp. This was compared to 71 percent who walked with a marked limp or who couldn’t walk at all before the operation. In addition, many more patients were able to go up and down stairs again after TKR.

This study shows total knee revision or replacement can be done safely in patients over 90 years of age. The TKR is durable and reliable. The authors advise a careful exam before the operation. Patients with medical problems can be watched carefully to avoid problems.

Transcutaneous electrical nerve stimulation (TENS) involves putting electrical currents into the tissues of the body. It may sound like a torture device. But it is actually used to treat pain. Doctors don’t know exactly how it works. It is thought to create a sensation that overrides the pain sensation in the brain.

These researchers tested TENS in patients who had a total knee replacement (TKR). TKR can be a very painful surgery. But medicine such as morphine shouldn’t be heavily used in TKR patients. Too much morphine after surgery can cause other problems, such as nausea, vomiting, constipation, and reduced lung function.

For this study, TKR patients were divided into three groups. For the first 24 hours after surgery, one group got the standard self-controlled doses of pain medicine. The second group got standard pain medicine plus TENS. The third group got pain medicine and false TENS treatments. (The wires were placed into the bandages rather than onto the body.)

The researchers tried to compare the amount of pain reported by the patients. However, patients slept through much of the 24 hours and so didn’t give many pain reports. The researchers also looked at the amount of pain medicine each group needed. They found that all groups needed about the same amount of pain medicine. TENS seemed to offer no real pain relief at all. This study does not support the idea that TENS can be useful for acute pain after TKR.

If you tear the anterior cruciate ligament (ACL) in your knee, chances are the doctor will use part of your patellar tendon as a graft to repair it. The patellar tendon is located between the kneecap and the lower leg bone. The middle third portion is taken out and used to replace the torn ACL.

What happens to the patellar tendon? Does it grow back? This study takes a long-term look using repeated MRIs of the donor site in 19 patients over a period of six years. They report on the thickness, width, and appearance of the middle portion of the patellar tendon. The donor site was compared to the patellar tendon on the healthy knee.

The researchers thought they would see a normal donor site six years after healing. Other studies have not shown a normalization of the site in the short-run. Longer studies show the tendon increases in thickness up to two years later.

The authors report that the tendon tries to adapt by getting wider and thicker on either side of the gap. The size of the hole gets smaller starting as early as six weeks after surgery. At six years there’s still some thinning in the center of the tendon. The thickness on the sides returned to normal at nearly six years. The extra width stayed the same, and the center was still thinner than on the normal side.

The authors conclude that a harvested patellar tendon doesn’t return to normal. It does remodel itself even after two years, but the tissue quality is lower than normal. If the patient ruptures the repaired ACL, tissue to repair it again should come from someplace else (such as the hamstring tendons behind the knee). It’s not advised to take more tissue from the first donor site.

Children and teens who watch sports know that injured athletes are treated and get back on the field quickly. Even players with more serious injuries, like anterior cruciate ligament (ACL) tears, can sometimes return before the end of the season. With this model in mind, young athletes are surprised to find it doesn’t work that way for them.

Doctors are hesitant to reconstruct a torn ACL in a patient whose growth plates haven’t sealed yet. Anything that disrupts the growth plate (called the physis) can stop bone growth, possibly resulting in a shorter limb or some other bone deformity. There’s also the concern that ligament repair with an open physis puts the knee at risk for future injury.

In this study, 13 teenagers with open physes and ACL tears were followed. Surgery to reconstruct the ACL was delayed until bone formed over the growth plates. During the waiting time, activities were severely restricted. The teens could not play in team sports. Conditioning exercises were okay. Rehab to work on knee motion and strength were also approved. All of them wore a knee brace during their waking hours.

The researchers later measured the differences in injury rates between teens with delayed ACL reconstruction and those who had the surgery right away. There were some injuries in both groups, but they were equal in number, type, and severity.

The authors conclude that an ACL injury in youth isn’t an emergency. Surgery can be delayed until the bones mature without risking further knee injury. The key is to restrict jumping and twisting activities and to protect the knee with a brace. They report that age doesn’t seem to make much difference. There may be some greater risk of complications after surgery if the operation is delayed too long, however. In this study all ACL tears were reconstructed within one month of bone maturity.

The anterior cruciate ligament (ACL) in the knee is commonly injured. When it is torn completely, it must be surgically reconstructed. Most ACL patients have only one bad knee. But in up to four percent of cases, both knees have torn ACLs. Then the surgeon and the patient have a decision to make. Operate on one knee at a time (called unilateral ACL reconstruction)? Or reconstruct both ACLs during the same surgery ( bilateral ACL reconstruction)?

This study looked at the costs and early results of doing bilateral ACL surgery. Eleven patients who got bilateral surgery were compared to 33 patients who had ACL surgery on just one knee. All patients had the same rehab protocol. The patients were followed for two to three years.

The results looked equally good for both types of surgery. Both groups went back to regular activity about six months after surgery. There were no major complications in either group. Both groups had strong, stable knees after ACL reconstruction.

The cost analysis of bilateral surgery showed a large costs savings to patients with injured ACLs in both knees. Doing bilateral surgery cost 7,500 dollars less for each patient. Most of the cost savings was in operating room expenses. The authors conclude that bilateral ACL reconstruction is safe, effective, and economical.

There’s one big problem with follow-up studies in medicine: patients who are “lost to follow-up.” These patients are included in the study at the outset. But then they stop returning letters or phone calls, or just generally make themselves scarce. These “lost” patients can sway the results of studies if, as a group, their outcomes are not like the patients who stayed in the study. Luckily, most studies lose few patients to follow-up.

However, patients who don’t respond are more of a problem in mail surveys. And mail surveys are being used more and more by hospitals and doctors. After total knee replacement (TKR), mail surveys are often used to rate patient satisfaction and knee function. In this study, mail surveys were sent to 472 TKR patients. The survey included 10 simple questions. The answers were compared to the doctors’ records from the patients’ clinic visits. But the focus of the study was not so much on the answers. These researchers wanted to know if the nonresponders would in any way have changed the outcomes.

To do this, the researchers needed to make sure that all 472 patients answered the survey questions. For 83 percent of the patients, this was not a big problem. They returned their surveys after one or two mailings. The remaining 17 percent took some nagging. These 80 nonresponders got up to four further mailings and then phone calls until they answered the questions.

When the results were all in, the data was sorted by how quickly patients had responded. There were important differences between early responders and nonresponders. Early responders generally had:

Fluid-filled sacs that develop behind the knee are called popliteal cysts. They can be hard to get rid of and come back repeatedly after treatment. They often have thick, twisted roots that go deep. Two doctors from South Korea report on the use of arthroscopy to remove large popliteal cysts.

The study included 14 patients with cysts that caused loss of knee motion, pain, and pressure on the nerves. These patients were compared to a control group of eight patients with the same condition who had open surgery instead of arthroscopy.

In arthroscopic cyst removal, the doctor inserts a long, slender tool into the fluid-filled sac. A tiny TV camera on the end gives the doctor a good view inside. Fluid is removed from the cyst. Using a small, motorized shaver, the cyst is then shaved away. Doctors are careful to keep the shaver pointed away from nerves and blood vessels.

During the operation any flaps, thick bands, or other fibrous membranes are removed. Surgeons check the knee joint for other damage. They often find frayed cartilage, meniscal tears, and arthritic changes. Arthroscopy allows them to treat these problems at the same time the cyst is taken out.

All patients having arthroscopic removal of the cyst had a good result. The cyst didn’t come back in anyone. Pain, swelling, and tissue tension were all gone by the end of three days. Patients were followed for at least one year and some for up to three years. The authors report this is a great improvement from past results, in which the cyst would return in at least half of all patients.

The authors of this study conclude that large, recurrent cysts behind the knee can be successfully treated using the arthroscope. The wall of the cyst and a valve must be removed for this to work. The authors also advise surgeons to correct other problems in the knee joint at the same time. This operation works well for patients who’ve had the needed to have fluid removal three or more times.

This is a case of a 25-year-old man from Italy who was in a car accident. He ended up with a large tear in the cartilage of his knee. A layer of bone underneath the cartilage was torn, too. Such an injury is now being treated with autologous chondrocyte implantation (ACI).

ACI is a two-step operation. First some cartilage cells (chondrocytes) are taken from the patient’s own knee (autologous). The harvest site is an area that doesn’t bear weight. The cells are taken to the lab to grow more cells. Four weeks later, a second surgery is done using the lab cells to patch the hole. Sounds simple, doesn’t it? But it’s not.

Here’s how it works. The lab-grown cells form a layer of tissue the same shape and size as the hole that must be plugged. A special two-sided membrane is used to make this happen. One side is smooth to keep anything from getting in. The other side allows chondrocytes in to reproduce. The chondrocyte side faces the bone and allows the implant to become part of the damaged bone.

The second step is called a matrix-induced autologous chondrocyte implantation (MACI). A special glue is used to fix the implant to the bone. The fibrin glue makes it possible for the doctor to use an arthroscope to do the operation. An arthroscope is a slender tool that’s inserted into the joint. There’s a tiny TV camera on the end so the doctor can see inside.

Without the special glue and new arthroscopic tools, this type of cartilage defect would require a big operation. The joint would have to be opened up. The implant would have to be sewn in place. There’s a good chance ligaments and tendons in the area would be damaged in the process of getting to the injured site.

The authors say fibrin glue and new surgical tools makes MACI using arthroscopic surgery a safe and simple way to repair deep cartilage tears. Things can only get better as other instruments are made for special types of operations like this one.

Patellofemoral pain syndrome (PFPS) is a common problem among military soldiers in training. In fact, it’s the main reason soldiers are given a medical discharge. PFPS is also common among runners. PFPS causes pain behind the kneecap during running, squatting, and stair climbing.

Even though PFPS is common, we still don’t know exactly what causes it. Researchers suggest factors such as muscle weakness, loss of muscle control, and changes in the foot and ankle. How do we treat something when we don’t know what causes it? What works for one person may not work for everyone.

In this study, physical therapists in the military looked at the use of a shoe insert for PFPS. The insert is called a foot orthotic. They used an off-the-shelf and ready-to-use orthotic. It’s a premolded full-length insole that fits inside the shoe. It has a firm arch support and heel cushion. The shoe insert was combined with a modified training program.

Forty-five men and women with PFPS were examined before wearing the inserts. Range of motion was measured to assess muscle length. Many other measures of the knee and lower leg were taken, including alignment of the bones in the foot and ankle. The inserts were worn at all times for three weeks. All soldiers were given instructions to avoid kneeling, squatting, and deep knee bends. Marching was limited to one mile, with no running during the first seven days.

Sixty percent of the soldiers had a successful response with the orthotics. Success was defined as a 50 percent decrease in pain. The researchers found three factors linked with successful use of ready-to-use orthotics. Patients with an inflexible foot got the most help from the orthotics. They all had a flat foot, limited big toe extension, and only a small amount of movement of the navicular bone in the foot.

Orthotics can cost quite a bit when custom-made for each patient. Off-the-shelf orthotics are readily available and cost less. Finding out which patients can get relief from PFPS with the off-the-shelf type is helpful and can save money. The authors suggest that anyone who has PFPS and one or more of these risk factors may respond well to an off-the-shelf foot orthotic. They think the orthotics absorb the shock and put less strain on the knee.

Everyone who goes into surgery for a total knee replacement (TKR) knows the leg is weak from pain and disuse. When and how does muscle strength come back after the operation? Studies show that many patients have weakness and loss of function that can go on for years.

Electrical stimulation of the muscles improves strength in young adults. What effect will it have on older adults after a TKR? Physical therapists enrolled patients who were having both knees replaced at the same time in a study of electrical stimulation. Having subjects with both knees replaced gave researchers a chance to use electrical stimulation on only one side. Results were then compared to the patients’ own knee that did not get electrical stimulation.

Two groups were formed in this study. One group received the same exercises for both legs. The other group received neuromuscular electrical stimulation (NMES). The NMES group did exercise on one side and exercise along with NMES on the weaker leg.

Everyone started their programs after the staples were removed (about three to four weeks after surgery). Patients were treated three times a week for six weeks, for a total of 18 visits. They were followed for up to six months. Knee range of motion and quadriceps muscle strength testing were done at regular intervals.

Legs with NMES were found to be equal to or stronger than the other side. The patients were able to keep this strength even six months later. Strength continued to improve over the six-month period, but the major improvement occurred in that first three weeks.

The authors suggest a formal strength training program after TKR isn’t needed for a full six weeks. Using NMES in a rehab program after TKR may increase quadriceps muscle strength faster than just using a traditional exercise program. Three weeks may be all that’s needed. This was a small study, so final recommendations will depend on results from a larger study in the future.

Do your hamstring muscles feel tight? If they are, a new treatment combination may be just what you need.

The hamstrings are located along the back of the thigh to the back of the knee. Muscles sometimes shorten up after an injury and may become resistant to stretching. Sometimes inactivity is enough to tighten up a muscle. Physical therapists and athletic trainers often combine heat and stretching to help patients recover lost motion.

Clinicians want to know what form of heat works best. Researchers from the Athletic Training Program at Brigham Young University looked at the effects of one form of heat on muscle flexibility. Pulsed short wave diathermy (PSWD) was combined with stretching. Three groups of university students with tight hamstrings were part of the study. The first group had diathermy and stretching. The second group had a sham diathermy (the machine wasn’t actually turned on) with stretching. The third group was the control group. They rested on the table for 20 minutes, but received no heat or stretching.

Groups one and two were treated once each day for five days in a row. Hamstring length was measured with the subject lying on his or her back. The hip was bent 90 degrees and the knee straightened as far as possible. The angle of the knee was measured with a special tool called a goniometer. Anyone with less than 160 degrees of knee extension was considered to have tight hamstring muscles.

The authors report that the diathermy plus stretching had a much better result than the sham diathermy or the control group. In fact, the diathermy-and-stretch group had an increase of three times as much motion as the other two groups. There really wasn’t much difference between the sham diathermy group and the control group.

The results of this study may have some impact on treating patients with tight hamstrings. This is especially true for cases of tightness caused by inactivity or immobility. PSWD as a form of deep heat is a valuable tool when used with static muscle stretching.

Ever wonder if those stretching exercises are really doing anything? How long does the effect last? And do you need to warm up before stretching? These are the questions physical therapists asked in a recent study.

Therapists often include stretching exercises in rehab programs. The idea is to increase the flexibility of muscles and tendons. The hamstring muscle behind the thigh and knee is an important muscle to stretch. Studies show muscle tightness is a common cause of hamstring injuries in athletes.

In this study, 56 volunteers between the ages of 18 and 42 were divided into four groups. Group one did warm-ups (climbing stairs) and a hamstring (static) stretch. Group two did just the static stretch. Group three just did the warm up. Group four was the control group. The control group didn’t do any warm-ups or stretching, but they did lie on the floor for two minutes.

Hamstring length was measured before and after the interventions. Measurements were taken at 15 minutes, one hour, four hours, and 24 hours after the stretching. The control group was measured at each of these times, too. The hamstring length was measured in degrees by seeing how far the subject could straighten the knee when lying on the floor with the hip flexed at 90 degrees. This test is called the active knee extension test.

The authors found a big difference in hamstring length after stretching. The greatest gain in muscle length took place in the first 15 minutes after stretching. The length was still there 24 hours later. Warm-up exercises before stretching didn’t seem to make any difference. The lasting effects of stretching are important to prevent injury and improve muscle function. Stretching should be done within 15 minutes of an activity to have the best effect.

Once again magnetic resonance imaging (MRI) has given us a way to look inside the body and measure something we couldn’t see before. This time it’s how much contact area occurs at the patellofemoral (PF) joint. The PF joint is where the kneecap comes in contact with the lower end of the thighbone (the femur).

In the past researchers used cadavers (human knees saved after death for study) to look at joint stress. But without live tissue there’s no way to measure the effect of muscle contraction on joint loading. This is the focus of this study done by physical therapists. They used MRIs to view and measure the contact area in 10 healthy subjects. Is there more contact area on the inside (medial) or the outside (lateral) edge? What does the contact area look like as the knee is flexed? The researchers answered these questions. They also looked at the contact area while the quadriceps muscle was contracting. The quadriceps is the large muscle in front of the thigh. It goes over and around the patella and attaches just below it.

The therapists found a big increase in contact area on both sides of the PF joint as the knee bends. Contracting the quadriceps muscle didn’t make any difference. Contact area is the greatest by the time the knee is flexed 40 degrees. More contact occurs on the lateral side. The authors of this study explain these findings based on the anatomy and movement of the PF joint.

It’s good to know where the PF contact points are located and how much force is put on them. This information will help physical therapists prevent and treat problems at this important joint.

How can the doctor tell if a total knee replacement (TKR) is infected? The patient history, an exam, and lab results are helpful. Since lab studies are so important, researchers want to know if the lab values for infection are the same in a knee with an implant compared to a knee without an implant.

Fluid from the knee can be removed and checked for infection. The number of white blood cells (WBCs) and neutrophils are counted. Neutrophils are the WBCs that destroy bacteria in the body. The American College of Rheumatology sets the levels for bacterial infection. They say more than 50,000 WBCs and more than 75 percent neutrophils suggest infection. Normal joint fluid has less than 200 WBCs and fewer than 25 percent neutrophils.

Should these same values be used if a knee with an implant is infected? That’s what these doctors tried to find out. They looked at the records of 440 patients with TKRs. Eighty-six had WBCs measured before their TKR was revised. There were 50 knees free of infection and 36 knees with a bacterial infection.

The authors found a much higher WBC count in the infected knees. The infected group had 25,591 WBCs compared to 645 in the uninfected group. After studying the results of the lab values, the researchers found the best lab values for infection in a knee with an implant.

More than 2,500 WBC and greater than 60 percent of neutrophils can be used as measures of bacterial infection in TKRs. Both must be present at the same time. Using synovial fluid is one more test doctors can use to find infection in a TKR before repairing or removing it.

Rheumatoid arthritis (RA) is an autoimmune disease. Autoimmune means that the immune system sees normal body tissue as “foreign” and attacks it. In the case of RA the synovial tissue around the joint is affected the most. Inflammation of the synovium is called synovitis. RA can cause joint damage in more than one joint.

Patients with RA may need a joint replacement. But how long will the new joint last if the synovitis comes back? Researchers in Japan studied 128 patients with RA who got a total knee replacement (TKR). A specific kind of implant called the Kinematic prosthesis was used in each patient.

Thirteen to 19 years later, the authors found a total of 36 knees to include in the study. Some patients had died or couldn’t be found. Others had serious health problems that kept them from being examined.

Doctors measured pain levels, range of motion, and walking ability before and after the TKR. They also checked on the number of infections, fractures, and other problems after surgery. Some patients needed a second operation on the joint replacement. This is called a revision operation. Six patients had a total hip replacement and two others had an ankle replaced.

The results of this study showed survival rates of the Kinematic prosthesis in patients with RA was close to 94 percent after 15 years. The authors say this is satisfactory. The Kinematic implant compares equally, if not better, to other types of implants used in previous studies.

The six women in this report had much in common. They’d all fallen and broken the bone just above or just below the knee. All had osteoporosis and decreased bone mass called osteopenia. All were over 70 years of age. They all had severe arthritis and other health problems such as heart or lung disease.

Why were they the subjects of this study? Because they were all treated for the fracture with a brand new knee joint. And the results were exceptional. Older adults with these kinds of injuries often have many problems in treatment. The fracture doesn’t always heal, and pins to hold the bone together sometimes come loose. A total knee replacement (TKR) isn’t usually used because of the weak bone structure.

This group of doctors from the University of Vienna Medical School in Austria decided to try something new. Each woman was given a TKR. A special kind of implant was used for five of the six women. It’s called a constrained prosthesis. The posterior ligament inside the knee is saved so the implant has less motion than the unconstrained model. Only one patient received an unconstrained implant. All implants were cemented in place.

The authors report good results for all six women. Each of the women could get up the next day and put weight on the leg right away. Within six months they were pain free and could walk as far as their general health allowed. One patient could walk unaided, but the rest used a cane or a walker. Results were just as good up to three years later.

The results of this study suggest TKR is an option in treating fractures around the knee. Patients must be selected carefully, but TKR is possible even with severe health problems.

Total knee replacement (TKR) surgery can do wonders for an arthritic or damaged knee. But TKR is hard on the muscles around the knee. Surgery and the down time after surgery often cause these muscles to lose strength. Weakness is especially bad in the thigh muscles. Much of rehab after TKR involves strengthening the weak muscles around the knee.

Electric muscle stimulation (EMS) can help muscles gain strength. It seems odd that simply passing an electrical current through a muscle can build it up, but it’s true. EMS is sometimes used to regain strength after spine injuries. EMS has also been shown to help athletes build muscle. These authors tested using EMS in the thigh muscles after TKR.

Fifteen patients were given EMS treatments after TKR. They were hooked up to EMS for four hours a day over six weeks. They also had the usual physical therapy. A second group of 15 patients received just the usual therapy. Both groups were checked for walking speed, walking effort, and knee function before surgery. The same tests were repeated one, six, and 12 weeks after surgery.

Recovery was similar by most measurements. However, the EMS group could walk much faster at six and 12 weeks. The authors say this could be because the thigh muscle recovered more quickly. The authors conclude that EMS, along with physical therapy, can help in the recovery after TKR.

Some things are just meant to go together, like a hand in a glove. Or in the case of the knee, the cartilage and the anterior cruciate ligament (ACL).

Cartilage in the knee called the meniscus helps bear the load across the knee joint. It also holds the knee stable. These are two important functions, especially when the ACL is torn. For good function and stability, the knee joint needs both the meniscus and the ACL in place.

Since learning this, doctors have made every effort to save the damaged meniscus. When possible, the meniscus is repaired. If it must be removed, as little as possible is taken out. (Removing meniscus tissue is called meniscectomy). Sometimes it’s just not possible to save any of the meniscus. In this case, a new operation is performed. The missing meniscus can be replaced with donated tissue. This is called allograft transplantation. Allograft means it comes from someone else (a donor).

In this study, researchers compare the results of meniscal allograft transplantation when done with ACL repair. For some patients, this was their first ACL operation. For others, this was a second (revision) operation. The researchers were interested in the outcomes of a combined operation of this type. They also wanted to know if it mattered whether this was the first or second operation on the ACL. Results were measured using X-rays, strength testing, range of motion, and symptoms of pain or swelling.

Most patients had a good result with better function and motion in daily activities than the average person without injury. There was no joint swelling or tenderness. The level of function during sports was slightly lower.

The authors conclude that it makes sense to replace the meniscus when patients who’ve had a prior meniscectomy now need an ACL repair. The meniscus transplant helps protect the ACL graft. It also protects the joint cartilage and helps stabilize the knee joint. They report patients having a second operation on the ACL don’t do as well as those having surgery for the first time.

Surgeons generally use tendon grafts to reconstruct a damaged anterior cruciate ligament (ACL) in the knee. The tendon graft is usually taken from tissues near the patient’s own knee. In this study, the grafts were taken from the hamstring muscle along the inside of the knee. The “new” ACL is never as strong as the original one. ACL grafts sometimes tear or become loose and weak. Surgeons are always looking for ways to make the tendon grafts stronger.

Some doctors feel that strength could be increased by twisting or braiding the graft tendons before stitching them in. Not many studies have been done on this. Past studies usually involved animal tendons. This study used cadavers (human bodies preserved for research) to test tendon grafts. The authors put twisted tendon grafts in the knees of one group of cadavers. A second group got braided tendon grafts. A third group got the usual tendon grafts.

The authors then used a special machine to test the strength and stiffness of the grafts. The usual tendon grafts were the strongest and stiffest. Twisting the tendon grafts decreased strength by 26 percent and stiffness by 43 percent.

More study is needed before doctors will know for sure if braiding and twisting tendon grafts is bad in all cases. However, these authors worked hard to make the tests realistic. This means that the loads put on the cadaver knees were much like the loads put on real knees after ACL surgery. This study makes a strong case against twisting or braiding the hamstring tendon to reconstruct a damaged ACL.

Notice any changes in your balance as you get older? Are you less stable when reaching for objects? Afraid of falling? An exercise form called Tai Chi may be the answer. Tai Chi is an Asian mind-body exercise. Millions of Chinese have used this form of exercise for hundreds of years.

This study measured the effect of Tai Chi on knee joint sense of position and overall body balance. Two groups of older adults (60 years old and older) were tested. One group had practiced Tai Chi for at least three years. The control group had never done Tai Chi, but some were active in walking and stretching.

Tai Chi stresses exact joint positions, speed of movement, and directions. Each movement is repeated slowly and smoothly. When doing Tai Chi movements, the body is required to shift weight in all directions. Smooth, coordinated motion is the goal.

The researchers found adults practicing Tai Chi have much better sense of knee joint position. This is called proprioception. They have faster reaction times when leaning toward eight different target positions. When it comes to balance and falls, Tai Chi participants in this study were more stable than the control group.

The authors conclude Tai Chi practice can improve balance when shifting weight in different directions. By improving balance, the adult becomes more stable. Increased stability makes it easier to climb stairs, get on and off a bus, and perform other daily activities. Better stability also makes it less likely that you will lose your balance and fall.