SED rate is an indicator of inflammation.
I have had tendon problems in several tendons for the last ten years. Ankle, foot, hip, shoulder, elbow, hand. I've had PT for all of them, some multiple times and it really helped. I have to keep everything stretched and make sure I get some exercise, but not too much as to overdo and cause more pain.
I did read that lyme can get into tendons, but also some abx are known to cause tendon pain, such as the quinolone family - cipro, levaquin, avelox. I notice more tendon pain when I'm on any abx which makes the doc scratch his head and say, "I've never seen that." Yeah, I make this up :-(