 [ Symptoms ] are folate and l methylfolate lmf helpful for treating depression [ Disease ] hi since your pain is 4 weeks old and comes only with sitting down then you are having pain with muscle eccentric contraction only which is a sign of either a jumpers knee or an overload quadriceps strain which might be due to over activity or doing something unusual for your body see what have you been doing the last four weeks as a new or uncommon effort try kinesiotaping of your both quadriceps for a while