Play-It-Again Sports [http://goo.gl/maps/WoJpH] offers a great collection of used lacrosse gloves, armpads, etc.; hockey gloves are great, too, but lacrosse gloves are more flexible. Anyway, this particular store has more lacrosse/hockey gloves in comparison to their Pasadena, Simi Valley and San Fernando Valley branches.
Meanwhile, if you are looking for a great TKD & HKD martial arts for your kids, check out the school next door [https://goo.gl/maps/cDGNhk5hLkS2].