Are diabetics more prone to tendon/ligament pain and injuriy?

Don't think so: Diabetics are more prone to peripheral vascular disease and diabetic neuropathy , specially if diabetes is not well controlled

Maybe: Diabetes don't heal as well as non-diabetics, so it is possible that mild traumas or over-use injuries to tendons and ligaments don't recover as well, and then either add up to a noticeable injury, or make it more likely for the person to get a sprain or strain. Diabetics also have nerve problems, so sensations in the limbs become abnormal over time, possibly making one more prone to sprains.