You haven't seen a big commitment in advertising and sponsorships by Nike and adidas because the lacrosse market is still too small to justify it. They are both testing the waters. If the game truly explodes, they'll be set to take advantage. (By “truly explodes” I mean numbers that will make a real financial difference to multi-billion dollar companies like Nike and adidas.)

The interesting twist here is that Reebok is owned by adidas, yet they compete for a lot of business.

Under Armour has definitely progressed from “just” a lacrosse brand. Will they re-enter the lacrosse market as an equipment manufacturer? I wouldn't be surprised either way. Some people are believers in the “do what you've been doing” attitude like DeBeer while others are always looking to expand, like Warrior did with Hockey gear and Nike, Adidas and Reebok are now doing with lax.
Under Armour has a HUGE following in the lax world, a great design team (their gear is always fresh) and an obvious understanding and lineage with regards to lacrosse. They sponsor the HS AA game and the helmets from that event are always a hot commodity.

I guess my only question would be if UA starts to produce padding, it wouldn't really be under anything anymore… would they call that section of their company “Actual Armour”?

You haven't seen a big commitment in advertising and sponsorships by Nike and adidas because the lacrosse market is still too small to justify it. They are both testing the waters. If the game truly explodes, they'll be set to take advantage. (By “truly explodes” I mean numbers that will make a real financial difference to multi-billion dollar companies like Nike and adidas.)

The interesting twist here is that Reebok is owned by adidas, yet they compete for a lot of business.

Under Armour has definitely progressed from “just” a lacrosse brand. Will they re-enter the lacrosse market as an equipment manufacturer? I wouldn't be surprised either way. Some people are believers in the “do what you've been doing” attitude like DeBeer while others are always looking to expand, like Warrior did with Hockey gear and Nike, Adidas and Reebok are now doing with lax.
Under Armour has a HUGE following in the lax world, a great design team (their gear is always fresh) and an obvious understanding and lineage with regards to lacrosse. They sponsor the HS AA game and the helmets from that event are always a hot commodity.

I guess my only question would be if UA starts to produce padding, it wouldn't really be under anything anymore… would they call that section of their company “Actual Armour”?