A study conducted years ago took 10 normal knee subjects and injected saline solution into their knees measuring quadriceps activation through EMG measurements. Their findings showed that the quadriceps could be inhibited as much as 30% to 40% depending on the muscle of the quadriceps. Ranges of fluid amounts showed different levels of inhibition to different muscles of the quadriceps but the take home from this study is that fluid in the knee can affect the quadriceps and its ability to contract.
When we find swelling on the knee, clinical signs that are present are symptoms of poor stability, the knee giving out, or hyper-extending.
When the quadriceps is inhibited we compensate by using our soleus to stabilize the knee when our foot is flat on the ground. This will change our gait and is a compensation. It is the reason why when you find iliotibial or IT band tension, and even swelling in the knee clinically, that you find deep calf muscle knots or trigger points present.
Symptoms of knee swelling
- Knee gives out or feels less stable
- Calf tension and muscle trigger points
- Pressure around and above the knee
- Outside thigh tension
Things to look for
- A puffy or swollen knee, specifically above the kneecap or patella, and to the sides of the patella
- A positive patellar tap test or ballottement test
- Iliotibial band tension and/or pain
Knee swelling is a sign that there is an underlying problem. It is not a diagnosis.
Self-massage above the knee, deep past the quadriceps tendon, is a great start to treatment. The idea of this is to stimulate the synovial lining of the knee as it extends quite far above the patella.
Dry needling is a great modality in reducing anterior knee swelling as well as treating quadriceps and soleus myofascial trigger points.
Finally, fix the cause! The reason for the swollen knee is that there is an underlying pathology or biomechanical problem present. Finding and addressing the cause is the role of the manual medical practitioner.