I recently was diagnosed with slight wear on two of my cervical vertebrae.
My only way to account for this damage has been 17 years of aikido, as I have not suffered any other traumatic insults to my neck.
Most of the time I have practiced aikido I have been technically obese (~33% body fat), putting me at about 246#. Coupled with my height, 6'1", I have to wonder if I was at particular risk for injury. None of my fellow aikidoka who have practiced as much have reported any issues. (Nota bene: none of them are obese.)
We have practiced on standard 2" blue mats, with no other shock absorbing elements.
And so I am bringing this issue to the table: Ought obese students be allowed to practice given the elevated risk of serious injury? I think this ought to be considered, especially in regards to break falls.
Of what consequense is this "slight wear"? Could the reason be genetic rather than impact?
I wouldn't think the cervical vertebrae would take extreme strain in breakfalls. In rolls, perhaps, if the belly prevents the person from actually making a nice round form - the back is straight, the neck overcompensates by bending more. Perhaps.