The most common and most likely answer to this crossword clue is the 8 letter word HAMPERED
I've seen this crossword clue in The Sunday Telegraph
H
A
M
P
E
R
E
D
Buddy explains!

The straight part
We know that "incapacitated" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case incapacitated = hampered.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HAMPERED mean?
HAMPERED verb- To put into a hamper.
- To put a hamper or fetter on; to shackle
- To impede in motion or progress.
- Impeded or encumbered as if chained or fettered