Possible Clues:

• Walker
• WALKER
• Uninspired walker
• What train speed may turn out to be
• Lacking inspiration, he goes for a walk
• One attending GP for years say ran despite being ordered otherwise
• Train speed varies — that's commonplace
• Into prison, with a stride that's fettered, he walks
• Ordinary user of zebras
• Lame steed run in dreadful pain is not mounted