When i curl the toes in l foot there is pain at top of achilles tendon/gastroc tendon rght below the calf also feel twitches in calf. probable causes?

See your doctor: It is difficult to localize the lesion without both understanding the history of the discomfort, nor an examination which can help determine any other associated signs/symptoms. Because of where the muscles and the nerves traverse along the leg, it could be a variety of things. Please consult with your doctor for further evaluation.