lost hind action

Question
QUESTION: hello sir, can you explain me this report

"WALNUT CREEK (APP. KULDEEP SINGH) lost his hind action and got unbalanced at about the 600 metres thereby losing position.  Subsequent examination revealed that the rig was bleeding from both nostrils after the race."

ANSWER: HI -- THE HORSE MUST HAVE LOST HIS ACTION DURING THE RUNNING OF THE RACE FROM BLEEDING INTERNAL , CAUSING HIM TO WEAKEN AND SLOW DOWN LOOSING HIS POSITION IN THE RACE, JOCKEYS WILL LET THE HORSE JUST SLOW DOWN WHEN FEELING SOMETHING IS WRONG WITH THE HORSE IN A RACE. THAT IS JUST BEING CAUTIOUS AND SAFE FOR THE HORSE AND RIDER. THANKS ED HESS

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QUESTION: thanks for the answer. i am clear with your answer but what does "hind action" mean?

Answer
hi -- hind action is what the jockey feels when racing or galloping . the horse would feel like it is having trouble in the hind end while in motion. so the rider would tell the trainer that the horse feels off in the back end so the horse is having hind action problems.  thanks Ed Hess