Possible Clues:

• Painful condition of the joints and muscles
• Condition of one wearing new summer hat?
• Joint affliction
• I could break mum's heart, suffering ailment
• Their mum's a different cause of much pain
• Painful disorder of the joints
• Mum is earth-shattering persistent pain!
• Complaint of one in fancy summer hat
• Inflammation of the joints
• Disease has affected this ear, mum