stretch enough to touch my toes

is it possible that my legs are significantly longer than my torso to prevent me reaching my toes … or is this a cop-out?! i’m about 5’10, exercise and fairly flexible – I’ve recently started yoga and can manage a lot of the standing positions that involve the legs e.g. tree and variations on this, and my instructor told me I found this easy because my legs are long in proportion to my body and that it would come in time. but i just wanted to check if this is actually a legitimate reason for not being able to touch my toes. i can get within maybe about 6 inches of them (which is quite a gap) and i wondered if the problem was more likely to be in my back/spine, my arms or my hips. (personally i feel like its my back as when bending down i don’t fold from the waist but curve my spine down from the top … if that makes any sense?!)