That seems quite unusual to me. Generally, you have fight with pear trees to bring their branches down to horizontal. Like the other branches in your tree, pear branches tend to go straight up. The only way I ever get horizontal branches like this is when they get pulled down and permanently arched from the weight of hanging fruit. Anyway, IMO there's nothing wrong with this and in fact is quite desirable for collecting sunlight and setting fruit.

One possibility I will throw out there, it could be a bud mutation. In which case, you may now have a very unique variety. I know with ornamental flowering cherries, many of the 'weeping' varieties have a normal upright growing counterpart to which they are identical to except they have a mutation that causes the unusual shaped branch formation.

That is pretty neat looking!

I have a wild ornamental broken off low at the ground by a bobcat. I assumed it would was dead so it was a year later when I noticed shoots coming up and promptly grafted them. The grafts all grew cork screw like and similar to the unusual growth your tree is showing. There was a mulberry a few feet away so i let a branch grow out long which I tied the tree to corce it to grow up instead of out with branches going across the ground. I will let you know what happens. I've seen that similar growth on your tree on just one other tree and it was pyrus calleryana my tree. I'm not sure if it means it's partially incompatable betwee . The scion and rootstock but I don't think so. I suspect its caused by a high vigor rootstock pushing growth so fast its malformed.

Any chance you've been spraying lawn pesticides like 4D? Drift from pesticides can cause weird growth in fruit trees.

Speedster in my case I have not. I would never rule anything out though in my case I see callery pear when grafted with scions throw out horizontal limbs in many cases very quickly.