The popliteus muscle can cause and contribute to pain behind the knee. Prime indicators of popliteus dysfunction is an inability to lock the knee and/or you find your pain behind the knee worsens when walking downstairs or an incline. Pain from the popliteus muscle often mimics meniscus and other knee ligament and tendon injury pain.
The sartorius muscle can cause and contribute to burning stinging down the thigh to the inside of the knee. The inside of the knee may be hypersensitive to touch and pressure.
The vastus intermedius muscle can cause and contribute pain down the front of the thigh and knees. Pain increases when walking up an incline or stairs.
The vastus medialis can cause and contribute to pain on the inside of the knee and front of the thigh. Dysfunction in this muscle will cause your knee to buckle. It is one of the four quadriceps muscles.
The rectus femoris muscle contributes to knee and thigh pain. It also contributes to restless leg syndrome and "knee bugs".
The gastrocnemius muscle is a prime contributor to pain in the back of the knee. It can contribute to lower leg, ankle, and arch pain.