There is no musculature, nerve endings, or ligaments attached to these anamolies.
Where do you get this information? Everything I have read about them seems to suggest that they are physiologically an underveloped tail with muscles and everything else.
I guess I am asking for evidence for your claim please.
Aside from which, if humans developed atavisms that are not normally expressed alleles, one might expect to see traits that are more current to the evolutionary timescale. What I mean to say is that if humans are indeed primates and we trace our lineage back to primates with tails, we are taling about hundreds of millions of years in between. Why wouldn't excessive body hair be a more prominent atavism than tails when there has been a hundreds of millions of years of disparity in between?
IIRC, humans don't have any less hair than apes, it is just not as thick or long.
Also, an "atavism" from a recent ancestor may not be an atavism at all. The more recent it is the more it is likely to just be a normal part of our variation. It is only when some trait has been lost for a considerable amount of time and returns in a very strange and underveloped form does it even qualify to be called an atavism.
Hence you have whales and dolphins with legs. I have yet to here a creationist take any effort in trying to explain that one.
Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)