If you have a calcaneal spur that is in pain especially when you touch it. is that because its digging into a tendon such as achilles?

Not necessarily: Pain from a calcaneal spur is generally caused by inflammation where the soft tissue (tendon or fascia) attaches to the spur. You can have a spur in the back of the heel where the achilles' tendon attaches or on the bottom of the heel where the plantar fascia attaches. You can also have pain in these areas without having a spur, just strain on the soft tissue.