Does anyone know where I can find any of the following for the
human head/neck system:

1) Head movement envelopes
2) Forces head is able to generate to external interfaces in various
3) The "comfort zone" the head can effectively operate in as a
force generating device
4) Fatigue(muscle) limitations of a subject when using the
head for force generating in various contortions
5) Ability of a human to discriminate between displacements and
forces acting on the head

Ideally, I would like to obtain a model of the head/neck system that would
incorporate most if not all of the above parameters.

R. Flanagan