Impediment bringing in right horse at dressage? (8)

'impediment' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?

'in right horse at dressage?' is the wordplay.
I cannot really understand how this works, but
'right' could be 'r' (common abbreviation) and 'r' is found within the answer.
The remaining letters 'stutter' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'bringing' acts as a link.

Can you help me to learn more?