The influence of anthropometric measurements on cervical spine range of movement. A cross-sectional study.

Background: Anthropometric factors are suggested to influence neck range of movement.However, which factors may be relevant, and their strength of association remains questionable.Objective: Examine the associations between selected anthropometric measurements and neck ranges of movement.Methods: 90 healthy participants 18-60 years (mean=31 years) were measured for height, weight, anterior and posterior neck column length and neck circumference.Active range of neck movement was measured using an electromagnetic tracking system.Differences in neck column length, anterior and posterior slenderness ratios (ASR & PSR) and BMI were calculated.Associations between range of movement and explanatory variables were examined by correlation and linear regression for all participants and by sex.Results: Factors significantly correlated with range of movement differed according to sex.Following regression, flexion was associated with ASR in females (adjR 2 =0.08) and BMI and neck column length difference in males (adjR 2 =0.34), extension with neck column length difference in females (adjR 2 =0.08) and ASR in males (adjR 2 =0.22), lateral flexion with age in females (adjR 2 =0.26) and ASR in males (adjR 2 =0.12), and rotation with PSR in females (adjR 2 =0.10) and BMI in males (adjR 2 =0.27).Conclusion: Association between anthropometrics and range is limited in explanatory power.Each sex exhibits different combinations of explanatory variables.ASR may better explain variance in measurements than PSR.