I'm surprised you got to the third stall before they were trying to breaking the stalls down.The pig board is a great invention. It seems things have come a long way in pig farming since I was a lad.
Coincidentally, I worked on the largest pig farm in CT in the 1960's (Secchiaroli's in Waterford which is still operating today) and we used bushel baskets to hold over the sows' heads to keep them at bay while we gathered up their male piglets for castration (performed by the owners with a straight razor on a 2 x 12 board laid across the tops of the stalls). By the time two or three stalls had been done, the sows were wise to the fact that their piglets were going to be hurt somehow and became quite nasty and harder to manage. By the time we reached the end of the barn, the sows were quite hard to keep under control. My job was getting into the stalls and grabbing the baby pigs with one hand while holding the basket over the mother's head with the other hand.
I once saw a huge sow leap over the side of a 4' high stall and bite one of my co-workers in the bicep while he was moving the castration board to the next stalls.
Inoculating the piglets (by a vet) required pretty much the same technique, but thankfully the sows did not get quite as upset on the inoculation days.
If you want the names and contact info for the two people I mentioned, let me know. I will send them to you in a PM.