The leg and bracket attachment point can loosen with use, and may require the occasional tightening of the double-nuts, which takes just a minute or two.
In order to tighten the legs you need:
(2) 10mm Wrenches or Small Adjustable Wrenches
(1) Set of Hands
1. Place first wrench on the inside nut.
2. Tighten the first nut only, to the desired friction you would like.
3. Hold the inner nut (the one closer to the bracket) still, while tightening the outside nut tightly against it.
4. Repeat Process for other side.
NOTE: Some wrenches can be thicker than the width of the nuts, and will not have the clearance to tighten both nuts at once. We have found that bicycle cone wrenches work quite well.