Answer from STS Forum
Hey Guys,
This was the answer I was given on the STS Forum for this same question from SNM:
"For a lot of lower body exercises a 1RM test is not necessary or advisable as your bodyweight and height will have more to do with the intensity of the exercise than the weight you hold. You also have to worry about comfort, form, balance and safety factors when doing a lot of lower body exercises that require you to hold a weight. This is why for a lot of lower body exercises we only give a rating of 1 or 2 stars, which means a 1RM test is not really necessary. For these exercises just select the maximum weight that you can comfortably control."