Why is my MCL strain not getting better? Because it is Pes Ancerinus Tendinitis.

When long-distance runners complain about knee pains, it is often complaints about pain in the front of their inner knee, below the knee cap. Pain comes about especially when climbing uphill or up stairs. Given the location, this pain is sometimes misdiagnosed as a MCL (medial collateral ligament) strain when it is actually Pes Anserinus Tendinitis.

What is Pes Anserinus Tendinitis?

It is essentially a inflammation of the tendons between your shinbone and muscles that form parts of your hamstring and thigh, .Three tendons (Semitendinosus, Sartorius¹ and Gracilis) join up to form the pes anserinus tendon. Pes anserinus in latin means 'goose feet' roughly describing the webbed look of the three tendon coming together.The pes anserinus tendon joins to the shin bone where the pain is usually felt.

Is it often mis-diagnosed as MCL or  medial-menicus strain because of the close location of the pes anserinus tendon to the MCL and medial menicus.

What strains the Pes Anserinus Tendon?

Things that strain the pes anserinus tendon are

1. Severe pronation of the feet – this causes the tibia (one of the lower leg bones) to rotate inwards which strains the tendons
2. Weak hamstring muscles – when combined with an intense running programme, the hamstrings may not be able to cope with the high workload. This is often an overlooked areas in a runner's strength training regime.
3. Tight thigh muscles (quadriceps) – weakens the opposing hamstring muscle. Muscles tightness here is further encouraged if you have a deskbound job that requires you to sit at the your desk all day long.
4. Sudden change on the volume and intensity of training

Diagnosing Pes Anserinus Tendinitis

Patients typically complain about pain climbing stairs, squatting, running and in severe cases, standing from a seated position.The pain would also appear gradually and for runners, following an increase in their training volume and intensity (uphill, or running faster).

However, even if your symptoms match those listed above, it is advisable to ensure that it is not other possible condition such as Patellar-Femoral Pain (PFP), MCL strain and medial-menicus strain

Treating Pes Anserinus

During the initial inflamed painful stage, your doctor may prescribe NSAIDs to help reduce the swelling and inflammation and recommend rest for the first 24-48 hours. Ice or cyrotherapy can help speed up the recovery by reducing the inflammation.

Once less painful, your therapist may suggest the following treatment depending on your cause of the tendinitis as list above.

1. For severe foot pronation – orthotics can help correct over pronation of your foot
2. To strengthen the weak hamstrings – see Hamstring Exercises for Long Distance Runners
3. Release tight thigh muscles with sports massage and a stretching programme.
4. A training programme that appropriately increases your training volume and intensity.

¹ Ed note. The Sartorius is the longest muscle in the human body