I work at a hospital, under a union. About a year ago, management approached me and asked me I I'd like take on an inventory position, since I have a fair amount of seniority, and the previous inventory person had left the hospital. Because I have difficulty saying "no", we eventually agreed that I'd trial the position for a while (though no time-span was set, and it was all verbal). The inventory position pays the same as my other current position, and there's currently 2 other people in rotation for inventory.

It's a year later now, and it's clear to me that I can't continue doing this job if I want to retain my sanity. I won't go into details, but not long after I joined the position, the work-load doubled due to new regulations, and the job became completely impractical for one person to be able to handle on a daily basis. Our team (the 3 of us) have been accumulating months of backlogged work, and it's only getting worse by the day. We've approached management and told them that we cant see how we're expected to get everything done everyday (but didn't mention that extent of the mess), and were told to get someone to help us when we need help; which is impractical on a daily basis since they're spreading everyone thin, and few of my co-workers even have the knowledge required to help with most aspects of the job.

Because of the constant stress that the daily mess provides, along with the accumulating backlogged work (and the fact that as a 6'2'' guy, my back is constantly sore from being forced to sit at a cramped desk), I want out.

The problems are though:

* We now have a new manager, and I'm not sure what was communicated to them.
* Even if they were told it's temporary, it's been almost a year, so they may have assumed that that's sufficient for trialing.
* **Most importantly**: to properly justify my wanting to leaving, I'll likely need to mention the months of backlogged work, **which management doesn't know about**. I'd rather not open that can of worms, then turn to my co-workers (who I still have to work with), and say "good luck dealing with management, I'm out".

My questions:

* How can I approach this scenario without "jumping ship", and screwing over my coworkers in the process?
* I figured that after I adjusted to the job, it may begin to become easier. After a year though, it's become clear that this job is only going downhill. Without a set time-span, is a year implicitly too long to consider a position for? Have a burned my escape by taking so long to decide?

To be clear though, I'm not intending to leave the company. I'm currently in 2 rotations: the inventory rotation, and the rest of my job. I'm intending to only leave the inventory aspect. I'll still be working in the same department, with the same people, just doing different tasks. This isn't me giving my 2-weeks, so I can't just shrug when management asks why I want to abandon that rotation.