Lateral restraint at Angle

[NewbieStruct]

We have an existing building where we need to use an existing equal angle (4x4x1/4) - 7" long at embed otherwise continuous (Leg is pointing down) long to resist a point load of 3.5 kips. The angle is attached to embed plate (welded top and bottom continuous at the leg pointing down) to the embed.

This is an existing tilt panel building with joists at the roof. These joists are resting on these angle. We are adding a mechanical unit
on the roof that will increase the load from 2.5 kips to 3.5 kips. Does the weld qualify as a lateral restraint allowing the design about the geometric axis? Will two shear plates below the joists help otherwise ?

 

[JedClampett]

I commend you for looking at every component in your check. Most of us would assume that a 4 x 4 angle could take the extra 1000 lb. and walk away. And I would definitely just check in straight bending. The joist plus weld unit would brace the angle from any twist. But if you want to be complete, you can add in the torsional loading and check it vs. twisting shear. It's likely to work, but I find out all the time that what I assume will work doesn't.
If it doesn't work, add a 3 x 3 angle and make a closed section out of the angle for the seven inches.

 

[Once20036]

I`m not clear on the geometry you're describing.
Is the length of the angle, 7", parallel with the wall? If so, I believe you have a case of plate bending with the top/horizontal 4" leg cantilevering out from the wall, and the restraint question isn't applicable. This is typically how I've seen joists supported.
If the length of the angle is perpendicular to the wall, your question is a good one to ask, but I typically haven't seen joists supported like this. I agree w/Jed that this would be restrained.