One way to avoid this is to flood all of the weight to your root joint. If you are unsure you need to go into the paint weights option. From here select the root joint and flood the weight to it. You are now able to have full control as you paint the weights on your model. I would advise starting at the hands and working your way into the chest, then the head, then body then the feet upto the legs and lower body. This is how I tend to do things but I am pretty weak with regards to rigging so go with what works best for you.

Also keep in mind if you model is mirrored on the other side you can mirror the weights so you only have to worry about getting one side of the model correct.

Hope this helps and best of luck