I have soreness behind my knee without an injury and no redness, swelling or warmth.

May be Bakers cyst. Even if you see no swelling it could be a tendinitis behind the knee or arthritis in your knee. Often a Baker cyst occurs with arthritis of the knee.

Related Questions

Hi Doc. I'm a 26 year old female. Have no history of injury. I recently started getting this sharp pain originating behind my knee and radiating down to my leg. No swelling, warmth, redness or tenderness behind the knee. It comes and goes without warning

Plantaris muscle . The plantaris muscle starts just above the back of your knee and goes down to your Achilles tendon at the heel. It is right in the middle of your calf. It doesn't stretch well. If overstretched It could give symptoms similar to what you described. Stretching the calf muscles by letting heels drop with balls of feet on a step usually helps. . Read more...