Definition: Knee Pain (Patello-femoral syndrome)
Symptoms: sharp pain and grinding sensation, especially when getting up from a chair or walking up a stairway
Causes: wear and tear, ageing, faulty foot biomechanics (over-pronation)
Treatment: orthotic insoles to correct foot pronation; knee braces; exercises, physiotherapy
Knee pain is very common. There are a number of different types of knee pain. The one described above is called Patello-femoral Syndrome or Chondromalacia Patellae. Other less common types of knee pain include Sinding-Larson-Johansson Disorder, Patella Tendinitis and Bursitis. Another more common form of knee pain is Osgood-Schlatter Disease which occurs only in children and adolescents. Another term for Patello-femoral pain is Runner's Knee.
Patello-femoral Syndrome is the most common form of chronic knee pain and is characterised by pain occurring between the knee cap (patella) and the underlying thigh bone (femur). It causes pain and tenderness in the front of the knee. It is also known as Anterior Knee Pain. (In contrast, pain behind the knee is very rare.) Patello-femoral pain is worse when you sit for long periods and get up out of a chair or the car, or when climbing stairs. Often, people experience a grinding or crunching sensation in the knee joint.
There are various causes of knee pain such as sports injury or trauma, as a result of an accident. However, in most cases knee pain is simply caused by wear and tear as a result of the normal degenerative process of ageing. Over the years the cartilage behind the knee cap (patella) will soften and wear out, resulting in small areas of soft tissue breakdown and tearing. Normally the knee cap glides smoothly over the knee with walking and movement. Instead, because of damage and roughening of the cartilage, the knee cap rubs and grinds against the thigh bone (femur) with every movement. This constant grinding leads to partial or complete erosion of the knee cartilage, causing pain and swelling. Apart from age, years of activities such as rugby, soccer, running, cycling or strenuous labour (e.g. on building sites) will affect the knees and exacerbate the erosion of knee cartilage.
In the knee joint there are two pads of cartilaginous tissue designed to disperse friction in the knee joint between the shin bone (tibia) and the thigh bone (femur). They are called meniscus (plural: menisci) and they can be found on the inside and outisde of the knee. In some cases pieces of the meniscus may tear away and a torn piece can begin to move inside the knee joint, getting caught between the bones, which in turn leads to pain, swelling and decreased mobility.
Another contributing factor to knee pain is muscle imbalance, whereby the inner quadriceps are weaker than the outside quadriceps. The stronger muscles on the outside pull the knee cap toward the side. Instead of the patella running properly in its groove, the muscle imbalance leads to mal-tracking of the patella, causing cartilage erosion and pain. This condition is also referred to as patella tracking disorder and it can be addressed by doing certain exercises which strengthen the weak muscles.
Apart from age, injury, trauma etc faulty foot biomechanics play an important role in Patello-femoral pain. Most health practitioners agree that the way we walk and the position of our feet and ankles have a profound effect on our legs, knees, hips and lower back. About 70% of the population have a condition called over-pronation. This means that the arches are lowered when the foot lands during walking and the ankles tend to roll inwards. Over-pronation not only affects the feet, it also causes the lower leg to rotate.
The knee forms the link between the upper and lower leg and is a hinge joint, designed to flex and extend the lower leg. Unlike our ankles and hip joints, the knees are not designed to rotate. However, when the foot rolls inwards due to over-pronation, the lower leg is forced to rotate, placing abnormal stress on the knee joint and resulting in poor knee function. This will inevitably lead to excessive wear and tear to the knee cartilage, causing long-term damage and chronic pain.
Many people suffer from over-pronation and most physiotherapists in Australia now include assessment of the patient's feet in the diagnosis of knee pain.
Knee pain treatment
Different types of knee pain demand different types of treatment. Athletes and runners often present with knee complaints as a result of injury. Sports injuries are usually treated by (sports)physiotherapists using the RICE method: Rest, Ice, Compression and Elevation. A typical sports injury in rugby and soccer players is rupture of the anterior cruciate ligament.
However, normal knee pain which has come about over time as a result of ageing, strenuous labour etc will require a different treatment regime. Chronic knee pain is best treated by a physiotherapist, but there's a lot you can do yourself. In some cases of chronic knee pain surgery is the only option left to achieve permanent pain relief.
Exercises for knee pain mostly involve strengthening of the VMO muscles (Vastus Medialis Oblique) which are part of your quadriceps (the muscles and ligaments in the upper leg in front of the thigh). The VMO is placed just above and to the inside of the knee cap. The VMO acts as a dynamic stabiliser of the knee cap. In pain-free individuals the fibres of VMO are active throughout the range of movement, contracting with ease. In people with Patello-Femoral pain these muscle fibres contract inconsistently and fatigue rapidly.
A strong VMO ensures the patella stays in the patella groove, controlling the tracking of the patella when the knee is bent and straightened. Please see the section below for more details on strengthening exercises. Most physiotherapists will recommend strengthening exercises to their patients as part of their knee pain therapy.
Knee braces are often prescribed by physiotherapists to stabilise the knee joint. There are many different types of knee braces available, the most commonly used being the Patella-Femoral brace, designed to improve patellar tracking and help relieve anterior knee pain. Patellofemoral braces resist lateral displacement of the patella, maintaining patellar alignment and tracking. They are not expensive and can be used in conjunction with other treatment options.
How foot orthotics can help relieve knee pain
Like knee braces foot orthotics are inexpensive and can be very helpful in the treatment of knee pain, provided they are used in conjuction with other forms of knee pain therapy, in particular strengthening exercises. By re-aligning the feet and ankles, orthotics prevent internal leg rotation, one of the causes of patella mal-tracking.
A number of studies have shown the benefits of orthotic insoles in patients with patello-femoral knee pain. A recent study by the University of Queensland showed significant improvement in patients with knee pain who were given a combination treatment of physiotherapy and orthotics, compared to patients who only received physiotherapy treatment. (See extracts from Knee pain and Orthotics research below).
Most top athletes wear orthotics to ensure proper alignment of their feet, legs and knees. Footlogics orthotics help restore proper knee function by correcting over-pronation, eliminating one of the causes of patello-femoral pain. If you have fallen arches and/or rolling inward of the ankles, there is a good chance that orthotics will provide you with some degree of knee pain relief.
In recent years a number of studies have been undertaken to measure the effectiveness of orthotic insoles in patients presenting with knee pain. Below are short extracts from these studies.
Knee Pain Study I
The Effect of Foot Orthoses on Patellofemoral Pain Syndrome (Knee Pain) - Amol Saxena, DPM* and Jack Haddad, DPM* - Department of Sports Medicine, Palo Alto Medical Foundation, Palo Alto, CA. Corresponding author: Amol Saxena, DPM, Palo Alto Medical Foundation, 795 El Camino Real, Palo Alto, CA 94301. From The Lower Extremity 5(2): 95-102.
In a retrospective review of 102 patients treated for chondromalacia patellae and patellofemoral knee pain syndrome/retropatellar dysplasia (PFPS/RPD), the effectiveness of semiflexible foot orthotics was investigated. The combined disorders were diagnosed in 89.3% of the patients. Subjects were 46 women and 54 men, aged 12 to 87 years (mean, 37.9 years; SD, 15.9), who exhibited excessive forefoot varus or rearfoot varus. The initial screening and clinical diagnosis were based on an examination by an orthopedist. Particular attention was directed to patellar crepitation, patellofemoral malalignment, Q-angle measurements, limitation of range of motion, and knee effusion. Patients were evaluated for the onset and duration of patellofemoral pain and degree of knee joint disease. Semiflexible orthoses for each subject were fabricated, based on a clinical lower extremity biomechanical examination. At their follow-up visit, 76.5% were improved, showing a significant decrease in the level of pain with orthotics intervention (chi-square P < .001). Although multiple treatment modalities are used for these patients, the results suggest that the use of semiflexible orthoses is significant in reducing symptoms of PFPS/RPD. (J Am Podiatr Med Assoc 93(4): 264-271, 2003)
Knee Pain Study II
The Role of Foot Orthotics as an Intervention for Patellofemoral Pain (Knee Pain)
Michael T. Gross, PT, PhD1- Judy L. Foxworth, PT, MS, OCS2
Foot orthotics often are prescribed for patients with patellofemoral knee pain. The purpose of this clinical commentary is to review the theoretical and research basis that might support this intervention and to provide our own clinical experience in providing foot orthoses for these patients. Literature is reviewed regarding (1) the effects of foot orthoses on pain and function, (2) the relationship between foot and lower-extremity/patellofemoral joint mechanics, (3) the effects of foot orthoses on lower-extremity mechanics, and (4) the effects of foot orthoses on patellofemoral joint position. The literature and our own clinical experience suggest that patients with patellofemoral pain may benefit from foot orthoses if they also demonstrate signs of excessive foot pronation and/or a lower-extremity alignment profile that includes excessive lower-extremity internal rotation during weight bearing and increased Q angle. The mechanism for foot orthoses having a positive effect on pain and function for these patients may include (1) a reduction in internal rotation of the lower extremity; (2) a reduction in Q angle; (3) reduced laterally-directed soft tissue forces from the patellar tendon, the quadriceps tendon, and the iliotibial band; and (4) reduced patellofemoral contact pressures and altered patellofemoral contact pressure mapping. Foot orthotics may be a valuable adjunct to other intervention strategies for patients who present with the previously stated structural alignment profile. J Orthop Phys Ther 2003;33:661-670.
Knee Pain Study III
Foot orthoses and physiotherapy in the treatment of patellofemoral pain syndrome: randomised clinical trial
School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia 4072
Foot orthoses produced improvement beyond that of flat inserts in the short term, notably at six weeks (relative risk reduction 0.66, 99% confidence interval 0.05 to 1.17; NNT 4 (99% confidence interval 2 to 51). Significant effects favoured foot orthoses over flat inserts at six weeks, with differences of 19.8 mm (99% confidence interval 4.0 to 35.6) on the continuous scale of global improvement, a number needed to treat of 4 (2 to 51) on the categorical scale (success equating marked and moderate improvement), and success rates of 85% (35/41) for foot orthoses and 58% (23/40) for flat inserts. Given the long term improvement observed in all treatment groups, general practitioners may seek to hasten recovery by prescribing prefabricated orthoses.
It is quite common for children and adolescents to complain of knee pain, especially if they are very active, play sports etc. Knee pain in children is caused by condition called Osgood-Schlatter Disease and it is part of the growing process. It causes swelling, pain and tenderness just below the knee and in some cases over the shin bone (the tibia). Osgood-Schlatter disease commonly affects boys more than girls and usually occurs immediately after a major growth spurt during pre-teen and teenage years.
During activities that involve a lot of running, jumping and bending — such as rugby, soccer, basketball, netball etc the thigh muscles (quadriceps) pull on the patellar tendons that connects the knee cap to the shin bone, causing pain an swelling in the knee area. Osgood-Schlatter usually dissapears with time. When your child stops growing, the pain and swelling should go away because the patellar tendons have become much stronger. Very rarely does Osgood-Schlatter Disease continue beyond the growing stage.
How should Osgood-Schlatter disease be treated?
First of all your child needs to cut down on time spent playing sports for 4 to 6 weeks, until the pain diminishes. Your child may also need to run at a slower speed or for a shorter amount of time and jump less often. For short-term relief you can apply an ice pack to help prevent swelling and relieve pain. Your physiotherapist may suggest that your child wear a knee brace to help the tension on the patellar tendons and quadriceps. It may take several weeks or months for the pain to completely go away.
If your child displays over-pronation of the feet (low or flat arch & rolling inward of the ankles) wearing orthotics inside the shoes are recommended, especially during sports and running. If quadriceps and/or hamstring tightness is present it should be addressed with stretching exercises.
Many studies have proven that strengthening of the quadriceps can be very beneficial in the treatment and prevention of knee pain. Also more flexible quadriceps will help you, as tight leg muscles can pull the patella out of line. Your muscles don’t work alone and if one group of muscles is particularly tight it won’t be long before the rest follows! Therefore stretching exercises are as important as strenghtening exercises. The quadriceps are one of the largest muscle groups in the body. The quadriceps muscles begin at our knee and run all the way up our thigh into our pelvis. Below are a number of simple exercises which can be done at home.
Strengthening Exercise 1: Leg lift
This is an easy exercise for beginners. Sit on the edge of a chair. Place your hands on the sides of the chair. With your legs at a 90-degree angle and your feet flat on the floor, slowly lift one leg up until it's completely straight. You'll feel your thigh muscles tighten once the knee is straight. Hold this position for about 10-15 seconds. Make sure your movements are slow for the best results. Let your leg go and place your foot back on the floor. Now do the same with your other leg. Make sure that you sit far enough into the chair so that it won't tip over while you do these exercises and fall off the chair. Do this exercise in both legs at least 10 times, so 20 times in total.
Strengthening Exercise 2: Squats
Stand up straight and place your feet hip-width apart. Put your arms straight out in front of you. Very slowly bend your knees and lower your body to a 90-degree angle from your knees. If you're not able to lower yourself to a 90-degree angle, just go as low as you can without straining yourself. As your quadriceps muscles get stronger, you'll be able to go a little lower every day until you can lower yourself to a 90-degree angle. While you're lowering your body, keep your upper body completely straight. Your upper body may try to bend forward, from your waist, but do your best to keep your back and waist straight and unbent. Beginners often tire after doing as few as five squats. If this happens to you, keep going. Try to gradually build your strength until you can comfortably do 15 squats.
Strengthening Exercise 3: Lunges
Lunges are another good way to strengthen the quadriceps and also your buttocks. Stand up straight. Take a big step forward, moving one foot out from your body while keeping the other foot in place as if you were walking. Simultaneously bend both knees until the leg that is in front is lowered to a 90-degree angle from your calf. Your front foot will be firmly placed on the ground, your back heel will lift from the ground. While doing the lunge, keep the rest of your body straight. Then return the outstretched leg back to your body while you return to an upright position. Repeat this exercise 15 times for both legs.
Stretching Exercise 1: Standing Quadriceps Stretch
Pick your leg up behind you whilst standing and hold your foot with your hand. Gently pull you foot in towards your bum. As you do this you should feel a strong stretch in the front of your leg. Only go as far as the point where you feel the stretch in the middle of the muscle and not at either your knee or hip. If you feel it at the either end of your upper leg then you have gone too far and must relax and take your foot away slightly until the stretch is back in felt only the middle of your upper leg. Hold this position for about one minute and then repeat the process for the other leg. Repeat this exercise 2-3 times for both legs.
Stretching Exercise 2: Kneeling Quadriceps Stretch
Place one knee on the floor and have the other leg bent with your foot flat on the floor and the knee bent at about 90 degrees. Your other leg should be beneath your body with the knee on the ground and your lower leg out behind you. Next with one hand grab the foot that is behind you and pull it towards your bum. You will find that it gets tight much quicker than the standing one as you have already started stretching it from the hip. Importantly, you must keep your upper body completely upright with this exercise. The temptation is to lean forwards but don’t as this will completely ruin the whole point of the stretch. Hold the stretch for about 1 minute and repeat it for the other leg. Do this exercise 2-3 times for both legs.
IMPORTANT: stretching exercises should never hurt, so don't overdo it! Always take big breaths in and out while you're stretching and relax into the stretch.