We still Hope
I think it's just the swelling from the injection, it probably was not rubbed well, or the frequency has made it sore. Happens to me all the time with Pent too. For the hip pain, could it be related to a recent physical activity? asides that, i am clueless...take care!
Why not rotate the injection sites?
My doctors always give me pent whenever I have crisis but it's usually through the vein while I'm on drip and I have never had any case of hardened muscles. Maybe it will help if your doctors can do the same. The hip pain might be due to stress. If you can relax for some days, it might help.