I am 22 years old male.My height is 5'6'' and weight is 56 kgs only. For the last few days I am having continuous ache in my muscles of the leg specially in the part below the knee.Thogh I have no pain at the joints.I am unable to deduce the reason and I think ,may be, I am having this problem due to weakness and malnutrition.Please give me some guidelines as soon as possible.