Not so good day at the park

The weather was so nice today, sunny and mid-70's this afternoon.  Perfect day for a trail run at the park.  When I got out there, Sara and J.C. were just finishing a long run, so I visited with them a bit.  I did not feel tired at all after the half marathon yesterday, so I decided to run a 2.5-mile loop.  My left knee is sore and a little swollen.  I got about 1.5 miles from the start and tripped on a root.  I have always advised people to go ahead and fall, rather than stumbling around trying to stay upright.  Skinned up knees heal quicker than pulled muscles.  Anyway, I decided to try to stay upright and stumbled around and felt like I was pulling muscles throughout my body.  After managing not to fall, I took a roll call of all the muscles to see what was still intact.  Looks like I pulled a groin muscle.  I ran/walked the last mile and took plenty of Ibuprofen with my dinner.  Hopefully, I will be okay for my half marathon on Saturday.