08/03/2007 at 01:50 PM EDT
Jenna Fischer spent her summer nursing four fractured vertebrae – but the Office
Emmy nominee insists she's almost 100 percent as her hit NBC show returns for a fourth season.
"I'm still sore," Fischer, 33, told PEOPLE at Thursday's Universal Media Studios Emmy party in Malibu. "I have good days and so-so days. I'm definitely able to work."
In The Office
, Fischer usually sits behind a computer. She adds, "They got a variety of chairs for me. I had to sit in, I think, six different chairs, and got to pick my favorite one."
Fischer, who hurt her back
after falling at an NBC party in mid-May, explains, "Truthfully, I'm not in a lot of pain anymore. It's more some discomfort. I don't have a headache, but I would say it's comparable to having a low-grade headache."
But her back has yet to recuperate fully. "I'm not allowed to start physical therapy yet. The bones have to completely heal first. I start physical therapy in about three weeks."
In the meantime, Fischer says some tasks are just difficult – or impossible. "There are little things all the time that I don't realize I can't do until I try to do them, like parallel-park my car," Fischer says. "It's the twisting behind me. It's certain muscles that you're not sure about yet. I'm just going to try to roll with it. Everyone is so supportive and concerned. I know it's going to be okay."
The show's first script read-through is Aug. 3 and production starts Aug. 6, cast members say. Fischer's Office
co-star Kate Flannery attests to Fischer's recovery.
"I had lunch with her today," Flannery tells PEOPLE. "She's slowly healing, and I think she's going to be fine."