Possible Clues:

• Control for horses
• Straps in a sleigh
• Stagecoach controls
• Controls are insupportable? Not entirely
• Controls no good in periods of monarchic rule
• Controls and rules we hear
• Checks on dialysis?
• Handful at 55-Across
• When by the sound of it His Majesty does this, he must keep them in his hands
• Equine steering gear