While more often than not, knee pain suffered here in Niseko is a torn ligament resulting from a fall, one of the most common forms of knee pain also occurs in winter sports: patella-femoral pain. This form of knee pain is usually of a more gradual onset, often as a result of overuse. Also known variously as patella mal-tracking, chondromalacia patellae or anterior knee pain, patellofemoral knee pain is common in people who are skiing or snowboarding regularly.
Patellofemoral pain refers to pain in and around the kneecap (patella), caused by irritation of structures in and around the patellofemoral joint as the patella glides on the thigh bone (femur) below. When the knee straightens and bends, the patella glides up and down a groove in the femur called the trochlea. The underside of the knee-cap is shaped perfectly to match this groove but if it moves too far to the side, problems can begin. The knee-cap has structures pulling it towards the outside (lateral) and the inside (medial), – a virtual tug-of-war, with the knee-cap as the rope! The medial movement of the kneecap is controlled by part of the quadriceps muscle called the VMO (vastus medialis oblique or ‘teardrop’ muscle in bodybuilding circles), and the lateral movement largely by another part of the quadriceps called the VL (vastus lateralis) and the infamous Illiotibial band (ITB).
Unfortunately for the poor old VMO, its nemesis the VL and its buddy the ITB often team up and take delight in beating up the VMO and yanking the kneecap too far to the side. This is particularly relevant in activities where the contact force of the back of the kneecap and the groove are increased. Normal walking increases these forces by 0.5 times body weight, whereas stair climbing can increase it by 7-8 times body weight. So it is easy to see why people with this condition often complain of pain using stairs (usually down is worse than up). More so, if you consider that when you are skiing it is in a semi squat position, it is understandable that pain can occur. And that’s not even taking into account the powder or bumps, which are both harder on the knees! Sometimes patellofemoral pain is called “moviegoers” knee, as pain is often noted with prolonged sitting upon watching a movie with the knees bent. Perhaps in the alpine environment it is better known as “chairlift goers” knee.
There are several factors that can contribute to the development of patellofemoral pain. As mentioned, overuse or an increase in the amount of an activity is one reason. This can be particularly relevant in skiing or snowboarding, whether it is the office worker on their ten day ski holiday that goes from zero to hero; or the endless winter workers who in some cases can spend more than 200 days per year on the hill!
There are also factors relating to the structure of the individual that can predispose to patellofemoral pain. These include:
• Weakness and/or wasting of the VMO muscle which lead to the kneecap not being pulled inwardly as the knee bends. Important to note is that the VMO muscle switches off when knee pain or swelling is present, and therefore an important aspect of rehab is to improve the activation of this muscle.
• Weakness of the pelvic stabilisers which are part of your ‘core’. If you are sloppy at the hips and around your centre, there will be increased forces acting on the knee.
• Inwardly rotated thigh bones, rotated shin bones, or ‘knocked’ knees which all alter the joint congruency and loads going through the patellofemoral joint.
• Inadequate flexibility of the lower limb, as tight muscles can lead to altered motions of the knee joint. The hamstrings, calves and ITB are particularly important.
• Pronating feet (feet that roll too far inwards when you walk), lead to more load on the patellofemoral joint.
• Patella position. Some people have a kneecap that sits too high, too low, or most commonly, too far to the outside.
So how is it treated you ask? The best advice is to see your local physiotherapist or sports physician who can offer a program catered to your needs. This program will revolve around correction of any of the predisposing factors as mentioned above. Activity modification may be required for a short period which may mean some relative rest and avoidance of aggravating factors. Rather than time off the hill, it may mean just changing some of your terrain selection, or increasing your breaks. VMO strengthening is crucial in order to help with the kneecap tracking. In addition to this, patellofemoral taping or bracing can yield an excellent reduction of pain, which may be key on a ski holiday to keep you out there. The tape or brace acts to help with the tracking of the kneecap and provide constant feedback to your ‘muscle memory’ as to where it should sit. ITB massage (ouch – they don’t call us physio-terrorists for nothing!) and lower limb stretching can really help. Pelvic and core stability work may be indicated. Foot bedding or orthotics in boots is useful for those who over-pronate. Reduction of acute pain and inflammation can be achieved with ice particularly after you ski, and anti-inflammatories as per your pharmacy advice.
Patellofemoral pain can be frustrating, but it is generally an easily treatable condition, and an appropriate treatment programme should see most symptoms resolved within 6 weeks. Surgery is generally not indicated. So, regardless of your ability, don’t let patellofemoral pain stop you snowploughing the family run or carving the white at the peak.