Q2. What are the common variables used in LBP research?
Nonlinear variables, that give insight into the dynamic structure of the sway pattern, have been used much less frequently in LBP research.
Q3. What is the role of muscle spindles in the detection of movement?
Muscle vibration is a potent stimulus for muscle spindles (Burke, Hagbarth, Lofstedt, & Wallin, 1976; Roll, Vedel, & Ribot, 1989) and muscle spindles play the major role in the detection of movement (Proske & Gandevia, 2012).
Q4. What is the effect of LBP on the postural sway pattern?
The authors hypothesized that, compared to subjects without LBP, subjects with LBP would show a more regular sway pattern, a decrease in response to lumbar paraspinal musculature (LPM) vibration and an increase to TSM vibration, that these differences would increase when standing on foam, and that recovery after cessation of vibration would take more time in subjects with LBP.
Q5. What is the main strategy for reducing the trunk to mechanical perturbations?
Subjects with LBP have been suggested to use stiffening strategy to increase robustness of the trunk to mechanical perturbations (Hodges & Tucker, 2011; van Dieen, Selen, & Cholewicki, 2003).
Q6. What is the role of the feedback mechanisms in the postural sway?
There is evidence that conscious control over a task increases postural sway (Andersson, Hagman, Talianzadeh, Svedberg, & Larsen, 2002; Nafati & Vuillerme, 2011) and that withdrawing attention from the postural task leads to a decrease in postural sway (Andersson et al., 2002; Nafati & Vuillerme, 2011; Riley, Baker, & Schmit, 2003).
Q7. What was the reliability of the parameters in the vibration trials?
For the vibration trials, proprioceptive parameters were included based on the findings in a previous study, and with at least a fair reliability in intra- and inter-day reliability (ICC > 0.4) (Kiers, Brumagne, van Dieën, & Vanhees, 2014).
Q8. Why do the authors suggest that attentional reserves are used less to control balance on foam?
In summary, the authors suggest that attentional reserves are used less to control balance on foam in subjects with LBP, due to pain interference.
Q9. What were the factors that were identified for CoP sway?
Four factors were identified for CoP sway, with a combination of variables that mainly represented velocity and range, and frequency and regularity both on rigid surface and on foam (Table 3).
Q10. What is the effect of fear of pain on sway?
The authors suggest that the competing effect of fear of pain on sway is achieved by means of increased use of co-contraction, specifically in the more challenging condition on foam.
Q11. What is the weighting of proprioceptive signals in subjects with LBP?
In addition, a54 0608.reduced weighting of proprioceptive signals in subjects with LBP is suggested as an explanation for the findings in this study.
Q12. What was the effect of the sway pattern on the subjects with LBP?
Subjects with LBP showed the same amount of sway as subjects without LBP, but the structure of their sway pattern was less regular with higher frequency content.
Q13. What other pathologies contain larger threats to postural balance than LBP?
The subjects in these other studies had pathologies that contain larger threats to postural balance than LBP does, such as CVA and Parkinson disease.