One of the physical "traps" Charlotte Perkins Gilman exposes—within her short story, "The Yellow Wallpaper"—is society's belief that men could control the lives of women, with the assumption that women were too fragile to deal with the real world because it caused them to be overly nervous.
The speaker sometimes has her doubts about her husband's prognosis regarding her state of mind, while at other times she believes that all he does is out of love for her. Yes, he is a doctor...
...and perhaps…perhaps that is one reason I do not get well faster. You see, he does not believe I am sick.
The unnamed narrator states:
If a physician of high standing, and one's own husband, assures friends and relatives that there is really nothing the matter wiht one but temporary nervous depression—a slight hysterical tendency—what is one to do?
Unfortunately for our protagonist, her brother—also a doctor— agrees with her husband. She is surrounded by men who believe nothing is truly wrong with her, so she goes "untreated" other than to be cut off from anything that might distract her and help her to feel better. She cannot read or write, and is not allowed to even see her new baby.
It is fortunate that Mary is so good with the baby. Such a dear baby!
And yet I cannot be with him, it makes me so nervous.
So the social trap that catches the speaker is in a male-dominated society that asserts that she cannot control of her own body, let alone her destiny. She is caught in a world where men own their wives, make their decisions for them, and women are fed the idea that this is normal and healthy. As an example, the Supreme Court contended that...
...states could withhold the right to vote from women as they did from criminals and the mentally insane.
Women—here—are placed in the same category as criminals and the mentally insane. The narrator buys it: she mentions several times how much her husband does for her, and how she hates to be a burden to him. What is most daunting is that this woman is completely under her husband's control; he exerts this power throughout the story. Economically and socially she depends upon him, and he treats her like a child. The only thing he cannot control, it seems, is her sanity.
The physical trap is seen in the actual control exerted over the speaker's body. Her husband does not "treat" her because he does not believe she is ill. She is "kept" in a large room on the third floor of their rented "summer retreat," that was once a nursery. With children in the room, bars were placed at the windows for their safety. For our narrator, they seem more like prison bars. This woman is expected to do nothing: she cannot read or write. In terms of the physical, she has also asked her husband to move her into a nicer room or take down the wallpaper. At first he agrees, but then he decides to leave her in the room, with the wallpaper. We read:
…afterward he said I was letting it get the better of me, and that nothing was worse for a nervous patient than to give way to such fancies.
The wallpaper becomes a focal point of this story. Leaving the paper represents her husband's determination to control his wife. For her, its presence haunts her:
…when you follow the lame uncertain curves for a little distance, they suddenly commit suicide...the color his repellent...
Then she sees faces and eyes in the it. As she pulls it down, she becomes a part of it, creeping along the walls, descending into madness.