Renault Grand Scenic Front Wipers Stuck

The front windscreen wipers have after gotten stuck on our Grand Scenic. I haven't had a chance to look at it properly yet, and it's started lashing right now but I'm hoping for some pointers for what to look for.

I was driving home in light drizzle and about two minutes from home the wipers seemed to extend too far, the passenger one came right to the edge of the windscreen, they then came back down to about a 15 degree angle. At this point they refused to move. I pulled in and lifted them so see if that would free them but to no avail. By rotating the passenger arm, the driver arm moved as well, but I couldn't move them any lower, just back up again.

I decided to wipe the windscreen and drive the rest of the way home with them up, thankfully the rain held off until just as I arrived home.

With the wipers turned off, about every 10-15 seconds they move down by about 1 degree for a moment, but then move back up again to where they were. I assume this is the return mechanism kicking in periodically.

With the wipers turned on, nothing seems to happen. I'm hoping it's just a fuse problem, but if it were should I be able to lower them by hand? Also, given they seemed to move higher than they should have when it happened it seems more likely to be something mechanical. I haven't gone out to listen for the motor.

Any pointers as to what I should be looking for?