hi,
neck position depends upon, what type of traction you want to give.
if it is manual traction, examine the patients reaction by giving traction in different neck positions, like neutral, flexion or extension. the most comfortable position and in which the symptoms are getting relieved should be used.
for mechanical traction, according to Kisner, to obtain vertebral seperation neck flexion of 35 degrees should be given. the greater the neck flexion, greater is the posterior elongation.
to obtain muscle relaxation position close to neutral should be given.
thanks