Which part of Mayella's body was beaten in chapter 17 of To Kill a Mockingbird?

In chapter 17, Sheriff Tate is the first person to take the witness stand and testify about the events that transpired on the evening of November 21st. When Atticus cross-examines Sheriff Tate, he asks Tate to describe Mayella's injuries. Sheriff Tate testifies that she was "mighty banged up" and says that Mayella had been beaten around the head and had bruises developing on her arms. Sheriff Tate also mentions that Mayella had a bruised eye and initially tells Atticus that it was her left eye that was injured. Atticus then corrects Sheriff Tate, and he testifies that Mayella's right eye was significantly bruised. Mr. Tate also testifies that there were bruises and finger marks encircling Mayella's throat, which indicates that she had been choked by her attacker. Since Mayella did not immediately see a doctor, there was no medical evidence proving that she had been raped. Mayella's injuries are significant to the case as Atticus argues that Tom Robinson was incapable of inflicting those specific injuries given his handicap. The fact that Bob Ewell is left-handed suggests that he was the person who punched Mayella in the right eye and choked her.

What are Mayella's injuries in To Kill a Mockingbird?

Mayella Ewell's injuries are certainly consistent with someone who's been badly beaten. As Sheriff Tate explains when he takes the witness stand, Mayella's right eye and the entire right side of her face were badly bruised, indicating that she'd sustained quite a beating. Not only that, but there were scratches all over Mayella's neck as well as additional bruising there, indicating an attempt at strangulation. The evidence was pretty compelling: someone had clearly attacked Mayella, just like she said.

But what the evidence did not show was that it was Tom Robinson who carried out the attack. In fact, due to Tom's disability—his left arm is useless after a boyhood accident—there's simply no way he could've attacked Mayella; it was physically impossible. The forensic evidence may be clear, but it still has to be interpreted in the right way; those cuts, abrasions, and bruises still need to be attributed to the right perpetrator. Unfortunately, that's precisely what the members of the jury do not do. They allow their racial prejudice to get the better of them and so they convict Tom Robinson of a crime which he did not commit and could not have committed.

Throughout Chapter 17, Sheriff Tate gives a description of Mayella’s injuries when he is on the witness stand during the Tom Robinson case. After solicitor Gilmer asks Tate to recall his story, Sheriff Tate begins to describe how Mayella looked pretty beat up. He said that Mayella had been beaten around the head and there were bruises starting to form on her arms. (17.224) Tate also mentions that she had a black eye. After Atticus questions Sheriff Tate in regards to which eye was bruised, he confirms that it was her right eye. In addition to her black eye, Mayella  also suffered marks to the right side of her face and neck. When Mayella showed Sheriff Tate her neck, he identified finger marks around her gullet. Tate says that the bruises on her neck went the whole way around.