The knee joint is the largest joint in the human body and one of the most complex. It is also very injury-prone, which often hampers the lifestyle of someone suffering from knee pain or discomfort. Knee pain is experienced by people of all ages. It can be divided into acute injury pain and chronic pain. The symptoms of chronic knee pain are very low-grade swelling and sensitivity, aching pain, giving way or locking, and extremely poor bending or weight bearing. Chronic knee pain, from whatever cause, almost always needs rehabilitation. Rehabilitation for knee pain can typically be in two forms. First, it can be self-administered with information gleaned from books, friends, or the internet. These forms of information might be okay, but often the knee is misunderstood or the pain can be misdiagnosed. The second and most effective form is with a physiotherapist who is the specialist in treating knee pain. This article will give the reader an understanding of the rehabilitation process and the various techniques a physiotherapist may use.
Rehabilitation Techniques
Physical therapy is an essential stage of recovery for patients suffering from knee pain, especially those inclined to avoid surgery or medication. This research project explores the use of physical therapy for rehabilitation of knee pain. Physiotherapists at Sime’s Site and NUH have been approached to find out the processes and exercises commonly used in their practices. These two locations were chosen to provide a well-rounded sample to represent most of Singapore’s public. Private practices are not discussed. Information provided ahead is a summary of the interview responses given by the specialists. Due to resource and time constraints, our research only samples a small pool of all practices in knee pain Singapore. Therefore, the processes and exercises mentioned in this paper may not be representative of all practices in Singapore. The patient referred to in the interview responses is the type who has pain and swelling in the knee joint and has difficulty with activities such as squatting, sitting with knees flexed, and walking up and down stairs. The objective of therapy is to increase the patient’s ability to carry out normal daily activities, improve strength in weak muscles, maintain endurance through cardio-respiratory fitness, retrain agility and lower limb proprioception, and finally, to restore full function of the knee joint and prevent any recurrence in the future. Sessions for therapy may vary from once every few weeks to several times a week, depending on how far post-surgery or injury the patient is and also the patient’s personal financial situation.
Physical Therapy
Exercise programs can be effective for both flexibility and strength and can be performed using both no equipment or various forms of resistance. Statically and dynamically resisted exercises have been shown to be effective in increasing quadriceps strength in people with PFPS. Isotonic exercise can be performed using weight cuffs, resistance bands or machine weights. Closed kinetic chain (CKC) exercises are commonly used in knee rehabilitation as the tibiofemoral joint compressive loads and the patellofemoral joint shear and compressive forces can be controlled depending on the degree of knee flexion. This can be effective in loading the joint in a pain-free manner as well as improving lower limb and core muscle strength and control.
Physiotherapy has been proven to be an effective approach in the treatment of patellofemoral knee pain by improving the strength and control of the quadriceps muscles. Reduced strength and earlier muscle fatigue of the vastus medialis oblique (VMO) compared to the vastus lateralis has been evident in people with PFPS. This alteration in force couple of the quadriceps muscles can result in abnormal patellar tracking and increased PFJ stress. VMO weakness is also associated with atrophy and inhibition of the muscle which can perpetuate the cycle of maltracking and pain. Therefore, strengthening exercises targeting the vastus medialis oblique (VMO) are effective as well as general quadriceps strengthening.
Exercise Programs
Exercise therapy aims to improve flexibility, strength, endurance, and overall fitness in the patient. It is classical and widely used, and may be adapted to suit the needs of the individual. Exercise therapy has been proven to be beneficial for patients with knee pain and curative for those with pain stemming from osteoarthritis. It would also be safe to assume that a patient with localized pain or generalized knee pain should benefit from such a program. Agility and lower limb tension are advisable for patients who have recently suffered from soft tissue injury or an anterior cruciate ligament tear. This may start from simple exercises such as leg raises and side leg raises before advancing to more agility and sport-related activities. High repetition step-ups effectively treat general knee pain and patellofemoral problems. Patients suffering from an osteoarthritic episode will find a prescribed regimen of strengthening and flexibility exercises to be beneficial, and it has been proven to offer an effective non-drug option for treatment. Static cycling and aquatic exercises are alternatives for general strength and conditioning exercises for patients with limitations to more functional exercises. Static cycling has been proven to produce benefits in pain relief and performance-based outcomes for patients with knee osteoarthritis, and its low-impact nature being kinder to the joints as opposed to cycling on land. Static cycling and hydrotherapy have the same benefits as overall strength and conditioning programs; however, there is evidence to suggest that it is more beneficial for patients with knee osteoarthritis.
Manual Therapy
In the case of the ACL-injured knee, therapeutic patellar mobilizations have been shown to improve patellofemoral joint mechanics following surgery. Using a variety of patellar movements typically classified under the Kaltenborn Joint Mobilization Grading system, mobilizations are followed by a series of taping techniques and vastus medialis oblique/vastus lateralis retraining exercises to prevent recurrence of poor joint mechanics. Progressive resistance exercise is often used in conjunction to increase strength and flexibility of the surrounding muscles. Although a popular choice for patients seeking to improve joint and muscle function, it should be noted that some patients may experience increased pain during or after manual therapy techniques and should ensure that they are applied by a qualified therapist with knowledge of their injury.
Manual therapy traditionally involves a hands-on approach with a primary focus on improving soft tissue extensibility. Research has shown that restoring full extensibility in the quadriceps muscle post-injury is vital in regaining full function of the knee extensor mechanism and reducing the chances of reinjury. Adhesion formation within muscle tissue is common after surgery or traumatic injury. Attempts to repair the tissue often result in the formation of a disorganized pattern of collagen fibers, usually in a random or haphazard fashion. This weak repair results in decreased flexibility, increased pain, and a higher risk of reinjury to the affected muscle. Certain forms of manual therapy, such as myofascial release techniques or instrument-assisted soft tissue manipulation, have been shown to be effective in breaking down disorganized collagen formation and adhesion tissue, resulting in pain reduction and increased function of the affected limb.
Specialized Treatments
Acupuncture Acupuncture is a Traditional Chinese Medicine (TCM) that has been around for over 2000 years. The technique requires the insertion of fine needles into the skin and tissue at specific points on the body. Acupuncture has been shown to provide pain relief for a multitude of conditions. The anatomy trains approach to acupuncture uses myofascial trigger points as energy or Qi points for electrical treatment. This technique is useful in promoting the release of endorphins and enkephalins to relieve pain at the point of need. For patients who are weary of injections or medicine, this treatment can be a safe alternative with minimal risk involved. With the increased availability of acupuncture, the patient is easily able to reach specialists who are able to provide professional knowledge regarding the procedure.
Shockwave Therapy Shockwave therapy is a non-invasive method that generates shockwaves to the affected area in order to stimulate healing. Studies have shown its efficacy in treating chronic proximal patellar tendinopathies, which is a condition that causes pain in the patellar tendon. The exact science of why shockwave therapy works is still unconfirmed; however, initial studies have shown promising results. Shockwave therapy is mostly used to replace traditional surgical methods. It is especially ideal for patients who wish to avoid surgery and has very minimal risk involved. Although the studies seem promising, shockwave therapy should be used as a last resort treatment as it is still new and there are gaps in knowledge. This should be discussed thoroughly with your knee pain specialist in order to weigh the risk versus reward.
Shockwave Therapy
Shockwave therapy was first introduced in the 1960s in Europe as a means to break down large kidney stones without surgical intervention. It has since been used as a non-invasive means to effectively treat a multitude of orthopedic conditions. The machines used for ESWT generate shockwaves by sending an electrical charge to an applicator, which conveys the energy to the applicator, creating an electrohydraulic, electromagnetic, or piezoelectric effect. The respective energy created is then focused and directed to the desired site on the patient with a level of precision. Once the shockwave reaches its desired location, the sudden pressure change creates a force that ranges between 100 Mpa to 150 Mpa, which is an extremely high value, causing it to affect and manipulate the targeted tissue. The process of shockwave therapy creates cavitation bubbles in the soft tissue, leading to increased cell permeability and changes in cell function, reducing the sensation of pain and sensitivity at the affected area. Coming off the momentum of a controlled inflammatory response, fibrous scar tissue will develop in the joint to naturally support and stabilize the area. This procedure can be improved over time with successive shockwave treatments, allowing patients to delay or even nullify invasive surgical intervention.
Acupuncture
Historically, acupuncture has been used for a myriad of conditions and knee pain is no exception to this rule. Acupuncture involves the insertion of extremely thin needles through your skin at strategic points on your body. A skilled acupuncturist will be able to target areas of pain with a variety of needling techniques. Some of the techniques may include needling that is local to the area of pain or a more distal approach that might be needling away from the site of pain in areas such as the hands or feet. An acupuncturist might choose to use a combination of both local and distal needling in one session or in separate sessions. Treatment duration, frequency, and the specific details of needling techniques will vary considerably based on the acupuncturist and the patient involved. Electroacupuncture is another needling technique that can be used for knee pain. This involves attaching small clips to the needles and passing a small electrical current between needles. This method is said to facilitate the movement of Qi and blood and provide analgesic effects. Moxibustion and cupping are other modalities within the scope of traditional Chinese medicine that might be used in conjunction with needling. Moxibustion involves burning a herb close to the skin to provide warmth to an area of the body. This can be particularly useful in conditions of cold and damp such as osteoarthritis. Cupping involves creating suction with glass or plastic cups on the skin and this can be useful for a variety of musculoskeletal conditions. By drawing up the skin it can facilitate the flow of Qi and blood in local areas and provide some pain relief.
Lifestyle and Self-Care Tips
It goes without saying that there is a direct correlation between body weight and knee health. Being overweight advances the rate of osteoarthritis and other symptoms of knee pain. Studies have shown that by decreasing body weight and body mass index (BMI), there is a slower progression of cartilage degeneration and decreased risk of developing osteoarthritis. Remember, every pound of body weight adds 3-4 pounds of pressure on the knee joint. Thus, if an overweight person were to lose 10 lbs of body weight, it would equal to 30-40 lbs less pressure on the knee each time they take a step. Imagine the relief to those sore knees! Ask your physician or physiotherapist to help set a target goal for weight loss. Goals can be short-term and long-term and should be attainable. Combining the right amounts of physical activity and proper nutrition will guarantee weight loss. Remember that it is important to take it step by step. Rapid weight loss is not safe and can actually cause more harm than good. For example, if someone were to participate in a lot of high-intensity running or jumping, they could cause damage to the knee joint from the excessive forces. Always take the time to consult a healthcare professional. Personal trainers are also good to work with in terms of learning the right kinds of exercises and intensities.
Weight Management
Knee pain makes exercise difficult, and the lack of exercise can increase knee pain because of the weakening of surrounding muscle support. Water-based exercises are a great way to start exercising with knee pain as the buoyancy takes weight off the knee and allows greater movement. Cycling and stationary bikes are also good as the resistance can be gradually increased with weight loss and muscle strength gain. Tai chi is another exercise recommended for knee pain sufferers as it can improve mobility and leg strength. High-impact activities and excessive stair climbing should be avoided until knees are less painful. Always consult a medical professional to ask advice on suitable exercise.
In March 2005, researchers reported in the Annals of Internal Medicine that an intensive diet and exercise program can markedly improve mobility in people with osteoarthritis of the knee. Volunteers in the study who lost an average of 10% of their body weight had a 28% improvement in knee pain. Their mobility increased, they had less difficulty getting out of chairs, and they had faster walk times.
Losing weight is one of the most cost-efficient methods of alleviating knee pain. This is because every extra pound of weight exerts about 4 pounds of extra pressure on the knee. Therefore, if you are 10 pounds overweight, you are putting 40 pounds of extra pressure on your knees.
Proper Nutrition
The more complex weight loss diets will often result in not getting all the essential vitamins and minerals that we need from food to maintain healthy living. If a certain food group is eliminated, it often results in cravings for that food. And when it’s finally given in, it’s eaten in excess. Hence, the key to every diet is still moderation. A healthy well-balanced diet, with smaller portion sizes, can effectively lose weight. The weight may not come off as quickly with other diets, but it will be lasting because this is a change of habit. A healthy diet is also just as important during exercises and therapies because doing work to fix a knee problem is just looking to solve a problem caused by stress from a biomechanical issue. And our body weight is the main source of stress. Hence, lesser body weight means lesser stress on the knee and lesser pain experienced. But with exercises, there are some who are confused on what is a healthy meal pre or post-exercise. This is very important and links directly to the effectiveness of the workout and tissue repair.
Aside from actual rehabilitation, it is crucial to understand the importance of self-help (through therapies conducted at home and managing one’s weight) when it comes to the topic of knee pain. Having an effective diet to manage one’s weight is also linked to an important self-help topic when trying to effect and cure knee pain. Hence, this is also covered under diet. A diet in losing weight is just as important as an exercise program. It helps to make certain that the effort put in to lose those kilos will not go down the drain. Basically, it will just speed up the whole process. But the main point of a weight loss diet is to prevent those kilos from coming back. There are thousands of weight loss diets out there. But it is so often forgotten that the simplest way of modifying one’s diet to lose weight is to just reduce portion sizes because we have just eaten too much. This method results in lesser calories taken in, and it is the very simple equation of calories in vs calories out that will determine if weight is lost. Because each kg of body weight equals to 7000 cal, losing just half a kg a week means a 500 cal deficit a day.
Home Exercises
Then there are activities with a HADD (high average daily dose) such as hopping and running, which are particularly likely to load the knee and cause pain in patients with patellofemoral pain. These are all useful ways to help a patient understand and modify their activity pattern to improve their knee pain.
In advising a patient about exercise, it is helpful to classify the various forms of physical activity in a way that helps the patient readily understand the activity and its effect on the knee. For example, we can classify activities into those that improve the strength and function of the knee and those that impair it. Alternatively, we can describe activities according to whether they are weight-bearing or non-weight-bearing. This distinction is particularly useful for patients with osteoarthritis who typically experience an improvement in pain and function in the hours and days following non-weight-bearing exercise and a deterioration following weight-bearing activity. Weight-bearing activities may include running or many field sports. Non-weight-bearing activities include swimming and cycling.
Now that we have an idea of what the knee can and cannot tolerate, let us consider the application of various forms of exercise and activities on knee pain and how we can modify those activities to be more knee-friendly. Exercise is an important part of the rehabilitation of knee pain. In fact, if it is done in a systematic way, exercise itself can often eliminate the pain without recourse to therapeutic intervention.