VTAC Thigh Rig user reviews 

I've read reviews about some thigh rigs that won't stay in place; this is not one of them. The rubber grip on the back of the straps help keep it where you put it. Now, it's on your leg and you're running around, so some movement is expected; it's inherent to the system. It is larger than I would have expected, so if you have smaller legs, you may want to explore different options. It is important to place this correctly on your leg or else it has a tendancy to come unsnapped on the back if you crouch or squat. The velcro will keep it in place, just be sure to have it on your leg where stretching and pulling is limited when moving.