You just need to rebuild the muscles.
I run but I suffer planter fasciitis in my feet. When my muscles got use to the mileage it stopped. Over Christmas i stopped running for 3 weeks, then had a little accident so couldnt run for another 2 weeks. So 5 weeks off. First run back only 4 miles. The next day my legs ached. Last week after my run, the next morning i had planter fasciitis in my feet again. Since the weekend ive had to go back to running a mile a day to rebuild my muscles.
It doesnt take long to loose muscling. I would suggest that you have a short rides, or try not to do too much trotting till you rebuild to muscle memory.