title: New insights into neck-pain-related postural control using measures of signal frequency and complexity in older adults.
abstract: There is evidence to implicate the role of the cervical spine in influencing postural control, however the underlying mechanisms are unknown. The aim of this study was to explore standing postural control mechanisms in older adults with neck pain (NP) using measures of signal frequency (wavelet analysis) and complexity (entropy). This cross-sectional study compared balance performance of twenty older adults with (age=70.3±4.0 years) and without (age=71.4±5.1 years) NP when standing on a force platform with eyes open and closed. Anterior-posterior centre-of-pressure data were processed using wavelet analysis and sample entropy. Performance-based balance was assessed using the Timed Up-and-Go (TUG) and Dynamic Gait Index (DGI). The NP group demonstrated poorer functional performance (TUG and DGI, p<0.01) than the healthy controls. Wavelet analysis revealed that standing postural sway in the NP group was positively skewed towards the lower frequency movement (very-low [0.10-0.39Hz] frequency content, p<0.01) and negatively skewed towards moderate frequency movement (moderate [1.56-6.25Hz] frequency content, p=0.012). Sample entropy showed no significant differences between groups (p>0.05). Our results demonstrate that older adults with NP have poorer balance than controls. Furthermore, wavelet analysis may reveal unique insights into postural control mechanisms. Given that centre-of-pressure signal movements in the very-low and moderate frequencies are postulated to be associated with vestibular and muscular proprioceptive input respectively, we speculated that, because NP demonstrate a diminished ability to recruit the muscular proprioceptive system compared to controls, they rely more on the vestibular system for postural stability.
authors: School of Health and Rehabilitation Sciences, University of Queensland, St Lucia, QLD 4072, Australia; 'Department of Physiotherapy, Singapore General Hospital,, Outram Road, Singapore 169608, Singapore. Electronic address: j.quek@uq.edu.au.
authors: June
authors: J
authors: Quek
authors: School of Health and Rehabilitation Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
authors: S G
authors: SG
authors: Brauer
authors: School of Exercise Science, Australian Catholic University, Fitzroy, Victoria 3065, Australia.
authors: Ross
authors: R
authors: Clark
authors: School of Health and Rehabilitation Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
authors: Julia
authors: J
authors: Treleaven
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006801:Humans; D009334:Neck Muscles / Q000503:physiopathology; D019547:Neck Pain / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology*; D058067:Wavelet Analysis
keywords: Neck pain; Postural control; Sample entropy; Sensory re-weighing; Wavelet analysis