How to treat Anterior Knee Pain
There can be many causes of knee pain. Anterior knee pain orpatella-femoral pain is pain that is felt under the knee cap (patella) at thefront of the knee. The patella, or kneecap, can be a source of knee pain whenit fails to function properly.
Alignment or overuse problems of the patella can lead towear and tear of the cartilage behind the patella. Patella-femoral painsyndrome (anterior knee pain) is a common knee problem that affects the patellaand the groove that the patella slides in over the femur (thigh bone). Thekneecap together with the lower end of the femur is considered to be thepatella-femoral joint.
Anatomy of the Area
What is the patella,and what does it do?
The patella (kneecap) is the moveable bone on the front ofthe knee. This unique bone is wrapped inside a tendon that connects the largemuscles on the front of the thigh, the quadriceps muscles, to the lower legbone. The large quadriceps tendon together with the patella and patellarligament is called the extensor mechanism. Though we think of it as a singledevice, the extensor mechanism has two separate tendons, the quadriceps tendonon top of the patella, which connects the quadriceps muscle to the top of thepatella, and the patellar tendon below the patella, which connects the lowerportion of the patella to the shinbone (tibia).
The tendon above the patella is called the suprapatellatendon and the tendon below the patella is called the infrapatella tendon.
Tightening up the quadriceps muscles places a pull on thetendons of the extensor mechanism. This action causes the knee to straighten.The patella acts like a fulcrum to increase the force of the quadriceps musclesas well as protecting the quadriceps tendon as it passes over the femur.
The underside of the patella is covered with articularcartilage, the smooth, slippery covering found on joint surfaces. This coveringhelps the patella glide (or track) in a special groove made by the thighbone,or femur. This groove is called the femoral groove.
The “v” shape on the underside of the patella and the “v”shape on the upper side of the femur fit together and assists the tracking ofthe patella on the femur during movement of the knee.
Two muscles of the thigh attach to the patella and helpcontrol its position in the femoral groove as the leg straightens. These twomuscles are part of the quadriceps group and are called the Vastus MedialisObliquus (VMO) and the Vastus Lateralis (VL). The VMO runs along the inside ofthe thigh, and the VL lies along the outside of the thigh. If the timingbetween these two muscles is off or one is stronger than the other then thepatella may be pulled off track and uneven rubbing will occur on one side ofthe articular cartilage on the back of the patella.
Potential causes ofAnterior Knee Pain and Advice to prevent it
As explained above, poor tracking of the patella in thefemoral groove as the knee moves. This causes excessive stress on the back ofthe patella thus wearing and irritation of the cartilage. This can be due to:
i. Muscle imbalance between VMO and VL (thighmuscles – see above) the patella gets pulled sideways by the stronger muscle,irritating the cartilage on that side.
If you feel this is an issue, strengthen your thigh muscles to correctthe imbalance
ii. Muscles within the lower extremity being tootight – e.g. quadriceps itself (front of thigh), hamstrings (back of thigh) andgastrocnemius (a calf muscle)
If you feel that this is an issue, ensure adequate length of muscles andgood range of movement at the knee by undertaking a regular stretchingprogramme
iii. The muscles of the hip control the position ofthe knee. A weakness of the muscles that pull the hip out and away from theother leg, or turn the thigh outward (hip abductor and external rotatormuscles,) can lead to imbalances in the alignment of the entire leg includingthe knee
If you feel this is an issue, strengthen your hip muscles to correct theimbalance
iv. Poor foot control, flat feet or feet rollinginwards causes inward rotation of the knee and therefore poor tracking of thepatella
If you feel that this is an issue for you please visit your GP, CharteredPhysiotherapist or Podiatrist to receive an expert opinion and appropriateintervention
v. Wear and tear as a result of acute injury to thepatella e.g. a fall or chronic friction between the patella and the femur suchas during jumping
Activities
i. A sudden introduction or escalation in hill /stair activity
Walk up stairs leading with your unaffected (pain free) leg, walk downstairsleading with your affected (painful) leg. This can be remembered easily by thesaying ‘the good leg goes up to Heaven, the bad leg goes down to Hell’
Graduate or phase the increase in the activity. If this is not possiblewithin a work environment make use of escalators / lifts where possible andreduce over time to create the phased approach
Take regular short breaks and when safe to do so
ii. A sudden introduction or escalation in Squatting
Try to raise the area to waist height e.g. use raised beds in a garden /garden centre or place a case / box onto a higher workbench
Use a low chair / stool where possible e.g. a teacher bending down at theside of a young child at school when he/she needs help in the classroom, shouldsit next to them on a chair
Kneel using kneeling pads and alternate the kneeling position / leg
iii. Weight bearing through a bent knee
Try to minimise this activity, but when you do so ensure that yourpatella is lined up with the midline of your foot (so when you look down you cansee your big toe on the inside of your bent knee) and clench your buttockmuscles for power
iv. Cycling with your saddle at the incorrect heightand putting the pedal in your instep rather than on the ball of your foot
Get your saddle height approved by a ‘professional’ i.e. bike shopassistant
You should have a 5-10 degree bend in your knee when the ball of the footis placed on the pedal and the pedal is positioned in its closest position tothe ground
Cycle with the ball of the foot on the pedal – not the instep / arch ofthe foot!
v. Prolonged postures such as sitting and gettingup from prolonged sitting
Keep your knees moving when you are sitting down
Ensurethat your workstation is not cluttered and that you can stretch out your legswhile you sit
Clothing /Accessories
i. Poor footwear - unstable or not fit for theactivity undertaken
Wear suitable shoes for the activity and also for your foot biomechanics(type, fit and condition of footwear)
ii. Restrictive clothing around the hips / kneese.g. tight pencil skirts
Wearsuitable clothing for the activity that allows a good knee position
Signs and Symptoms ofAnterior Knee Pain
The most common symptom is pain underneath or around theedges of the patella. Often the pain radiates to the medial side of the kneecap(the side closest to the other leg) whereas others experience vague pain in theknee that isn’t centred in any one spot.
The pain is made worse by any activities that load thepatella-femoral joint, such as running, hill walking, or going up and downstairs. Kneeling or squatting is often too painful to even try. Keeping theknee bent for long periods, such as when sitting in a car or during a movie mayalso cause pain.
Sometimes there may be a sensation like the patella isslipping or giving way on activities such as jumping or running. Most oftenthis is thought to be a reflex response to pain and not because there is anyinstability in the kneecap.
The knee may grind, or you may hear a crunching sound whenyou squat or go up and down stairs. In most cases this is nothing to worryabout if pain is not present in the knee. If there is a considerable amount ofwear and tear, you may feel popping or clicking as you bend your knee. Thesesounds are caused by the uneven surface of the underside of the patella rubbingagainst the femoral groove. The knee may swell with heavy use and become stiffand tight. This stiffness can be because of fluid accumulating inside the kneejoint, sometimes called ‘water on the knee’. This swelling is not unique tothis condition but sometimes occurs when the knee becomes irritated.
Aiding Recovery witha Home Exercise Programme
FIRST AID ADVICE (IMMEDIATELY AFTER THE INJURY)
The best results after a knee injury come when treatment isstarted right away. A simple way to remember the essential steps of initialtreatment is by the letters in the word RICE. These stand for rest, ice,compression, and elevation
REST
The injured tissues in the knee need time to heal. Restprevents further injury and reduces the stress on already inflamed tissues. Ifthe injury is severe crutches or a walking stick (placed in the opposite handto the injury) will prevent too much weight being placed on the knee in theearly days of injury when walking is essential.
ICE
Applying ice will help ease pain and reduce the swelling andwarmth. You should apply the ice as soon after the injury as you can to preventas much of the inflammation developing as possible. This will help ensure aspeedy recovery. It is advised to apply ice in the form of crushed ice cubes,frozen peas or an ice pack. DO NOT apply directly to your skin, oil can beapplied to protect the area. All of these are to be wrapped in a damp tea toweland applied to the knee for approximately 15 minutes every 2 hours. It isadvised that you check the skin every 5 minutes to avoid the possibility of anice burn from the cold temperature. Apply frequently in the first 2 days
COMPRESSION
Use Vivogrip (elasticated tubular bandage available here) on your knee, this will help prevent inflammation and swelling. Applythe tubigrip from mid thigh to mid calf, make sure it is not too tight and takeit off at night time.
ELEVATION
Supporting your knee above the level of your heart helps tocontrol swelling by aiding your body to reabsorb the fluid that has leaked intothe tissue. Ideally lie on your bed or the sofa or floor and prop your knee upon pillows or a chair so that it is higher than your heart. Even propping yourknee up on a chair if you are unable to lie down (e.g. at work) is beneficial.
Further Self Help
If swelling in the knee is severe, self-massage can help.Apply massage strokes from the knee toward the hip with your leg kept in anelevated position. This helps get the excess tissue fluid moving out of the kneeand back into circulation.
Gentle mobilisations of the patella from side to side canaid pain relief and reduce swelling and stiffness. You must sit up straightwith your back supported (hips bent to 90 degrees) and your legs straight. Thiscan be done while sitting on your bed with your back supported by theheadboard, or sat on the floor with your bottom against the skirting board andyour back supported by the wall. Reach out to your knee with your arm whileyour back is still resting on the wall. Your sitting position is important asif you lean forward away from the wall, your thigh muscles will tighten and youwill not be able to move your patella!
Mild pain relievers may help with the discomfort.Anti-inflammatory medications can help ease pain and swelling and get peopleback to activity sooner. These medications include common over the counterdrugs such as ibuprofen. Talk to your Doctor or Pharmacist if you have specificquestions about which pain reliever is right for you.
Avoid repetitive activities or prolonged activities ( suchas sitting for a long time) that aggravate your symptoms until you are feelingmore in control of the pain and slowly reintroduce these activities. Forexample driving long distances, break up the drive by taking frequent breaks.
RANGE OF MOVEMENT ANDSTRENGTHENING EXERCISES
Please discuss with your Physiotherapist which exercises are right for you. The type, duration and frequency of the exercises will depend onthe structure and grade of your injury and where you are in the recovery phase.
Please remember to use this advice under the guidance ofyour Physiotherapist.
Mark Fletcher MCSP HCPC(PT) ACPOHE is a Senior Chartered Physiotherapist and the Clinical Director of Physio Med. Mark has worked for the NHS and was the lead Physiotherapist to the Bradford Bulls Super League club before forming Physio Med. Physio Med have been delivering quality care across the UK for 24 years.
To find out even more about knee problems, visit the ‘Know Your Body’ section of Physio Med's site.
www.physiotherapyinleeds.co.uk/body-parts/knee
