A Bruising Relationship - What is the Explanation for Kate's bruised wrists?

One thing that was noticed right from the start of media coverage on the McCanns was that both had some pretty severe bruising around the wrist area.  This fed a lot of speculation that the couple had been fighting and indeed in her book I believe Kate confirms (??) that on the Wednesday night she transferred to the children’s room.  Some of the witnesses describe distraught, Muhajadeen style prostrating themselves and beating the floors with their fists after the initial discovery and in her book, she describes how she flails against the verandah railings etc.

In my view this is a classic example of two Kate traits designed to disguise the truth.  Over acting whilst recounting the narrative and back filling to attempt to explain away some of the most attention-grabbing anomalies.  They are usually careful to just not touch the subtler anomalies which they don’t expect to be picked up by the mass audience and do not wish to unnecessarily highlight.

Now, I’m no expert in bruises, but my uneducated guess is that those bruises are not derived from banging one’s fist on things but from a pretty spirited battle between Kate and Gerry.  The bruising on the wrists would seem to me more likely to have been the result of Gerry persuading Kate to accept a course of action (the cover-up) which she may well be inclined to be skeptical of. Those look like pretty serious bruises on both partners, so it looks to me that this was an argument about something pretty fundamental, not just a tiff over Gerry paying too much attention to the aerobics instructor or practicing his tennis  shots rather than helping with the kids.