There are of course a number of competing selective pressures acting on human populations (as well as a bottle neck in population size that can contribute to fixation of slightly deleterious mutations), and while pathogen load has been proposed as the most dominant driver of adaptation in the human lineage [ 70], cancer selection has a distinct possibility as a contributing factor [ 69, 73].
10 Patients experiencing whiplash associated disorders may be regarded as a distinct group within the broader non-specific neck pain population, 1 2 7 11–13 although following review of trial data (n=4 trials), recent evidence questions this distinction for a primary care population and has identified a need for further research.
In order to interpret the HN QOL literature, it is important to have an understanding of the significance and limitations of QOL assessments in the head and neck patient population as well as an appreciation for the currently available measurement tools.
In a study by Daffner et al. [ 7] 65.4% of the neck pain population included in their study had arm pain associated with their neck pain.
65, 95– 97 In the head and neck cancer population, recent clinical research has shown that exercise during the course of chemoradiation treatment helps preserve muscle mass with reduced negative nutritional outcomes common in this population.
Such studies could give rise to highly specific randomized controlled trials and ultimately to the development of individualized medical nutrition therapy regimens that may improve prognosis in the head and neck cancer population.
This homogenous physiotherapy mechanical neck pain population has only two-thirds with work status, cross-gender differential item functioning further reduces potential samples, and only 50 participants were examined for 'longitudinal validity'.
These findings may encourage future interventions to stimulate leisure time physical activity in chronic neck pain populations and to evaluate intervention effects on HRV and pain.
Again, a caveat is that this Quebec Task Force Classification may have more prognostic value in less severe and less persistent neck pain populations, especially where treatment is subgroup-targeted.
Thus, we suggest that this possible connection between physical activity, parasympathetic regulation, and inflammation should be further investigated in prospective studies in chronic neck pain populations.
