They are trained to feel for tight /rock hard muscles, some have a better feel for these things than others , but it sounds like they know what they are talking about..

Were trigger points mentioned , muscle spasms?

If they have IF stim instead of TENs that might be even better for healing..

If some proper soft tissue therapy can resolve part of your discomfort & symptoms wouldn't it be worth it?
If it isn't helping you can stop going.. just don’t sign any locked in treatment program agreement..
A sticky thread from the TOS forum with trigger point info- might be handy to be aware of this-
http://neurotalk.psychcentral.com/thread125577.html