Does any one else get these deep, leg aches?

i've had them since i was little, my sister complains of them too. I always seem to get them at night/before/during bed and they are like a really deep deep ache in the middle of your leg, usually in the knee, lower thigh or upper calve area. They go in an hour or two, and i get them maybe... 4 times a year?.. they almost feel as if when you tense or move your leg it actually helps, yet there is no pattern other than time of day that i get them. does any one else get this or are my legs crazy? lol x