Background The capacity of postural control is a key factor related to falling in older people, particularly in older women with low back pain (LBP). Cognitive involvement in postural control increases with age. However, most scholars have not considered different difficulty levels of cognitive loads when exploring the effects of cognition on postural control in older patients with LBP. The present study is to investigate how different levels of cognitive loads modulate postural control in older women with LBP. Methods This was a cross-sectional study. Twenty older women with LBP were recruited into the LBP group, and 20 healthy older women without the history of LBP were recruited into the healthy control group. Balance parameters were computed to quantify postural control. All participants underwent the balance test, which required the participant to maintain stability during standing on a force platform with or without a concurrent cognitive task. The balance test included three levels of difficulties of posture tasks (eyes-open vs. eyes-closed vs. one-leg stance) and three cognitive tasks (without cognitive task vs. auditory arithmetic task vs. serial-7 s arithmetic task). Results A repeated-measure analysis of variance (3 postural tasks × 3 congnitive tasks× 2 groups) testing the effects of the different congnitive task levels on the performance in different postural conditions. Older women with LBP had worse postural control (as reflected by larger center of pressure (COP) parameters) than control group regardless of postural or cognitive difficulties. Compared with the single task, the COP parameters of participants with LBP were larger during dual tasks, even though the difficulty level of the cognitive task was low. Larger COP parameters were shown only if the difficulty level of the cognitive task was high in control group. Correlations between sway area/sway length and the number of falls were significant in dual tasks. Conclusion Our findings shed light on how cognitive loads modulate postural control for older women with LBP. Compared with control group, cognitive loads showed more disturbing effects on postural control in older women with LBP, which was associated with falling.

Objectives. This study is aimed at exploring the effects of virtual reality (VR) training on postural control, measured by anticipatory and compensatory postural adjustments (APAs and CPAs, respectively), in patients with chronic nonspecific low back pain (CNLBP) and the potential neuromuscular mechanism of VR training. Methods. Thirty-four patients were recruited and randomly assigned to the VR group ( n = 11 ), the motor control exercise group (MCE, n = 12 ) and the control group (CG, n = 11 ). The VR group received VR training using Kinect Xbox 360 systems and magnetic therapy. Besides magnetic therapy, the participants in the MCE group performed real-time ultrasound-guided abdominal drawing-in maneuver (ADIM) and four-point kneeling exercise. The CG only received magnetic therapy. Surface muscle electromyography (sEMG) was used to record the muscle activities of transverse abdominis (TrA), multifidus (MF), lateral gastrocnemius (LG), and tibialis anterior (TA) during ball-hitting tasks. The muscle activation time and integrals of the electromyography activities (IEMGs) during the APA and CPA stages were calculated and used in the data analysis. The visual analogue scale (VAS) and Oswestry dysfunction index (ODI) scores were also recorded. Results. A significant interaction effect of time × group was observed on the activation time of TrA ( p = 0.018 ) and MF ( p = 0.037 ). The post-intervention activation time of the TrA was earlier in the VR group ( p = 0.029 ). In contrast, the post-intervention activation time of the MF was significantly delayed in the VR group ( p = 0.001 ). The IEMGs of TrA ( p = 0.002 ) and TA ( p = 0.007 ) during CPA1 significantly decreased only in the VR group after the intervention. The VAS scores of three group participants showed significant decreases after intervention ( p < 0.001 ). Conclusions. Patients with CNLBP showed reciprocal muscle activation patterns of the TrA and MF muscles after VR training. VR training may be a potential intervention for enhancing the APAs of the patients with CNLBP.

Introduction. The transversus abdominis (TVA) and multifidus (MF) muscles are the main segmental spinal stabilizers that are controlled by the primary motor cortex of the brain. However, relocations of the muscle representation in the motor cortex may occur after chronic lower back pain (cLBP); it still needs more evidence to be proven. The current study was aimed at applying transcranial magnetic stimulation (TMS) to investigate the changes of representation of TVA and MF muscles at the cortical network in individuals with cLBP. Methods. Twenty-four patients with cLBP and 12 age-matched healthy individuals were recruited. Responses of TVA and MF to TMS during muscle contraction were monitored and mapped over the contralateral cortex using a standardized grid cap. Maps of the center of gravity (CoG), area, volume, and latency were analyzed, and the asymmetry index was also computed and compared. Results. The locations of MF CoG in cLBP individuals were posterior and lateral to the CoG locations in healthy individuals. In the healthy group, the locations of TVA and MF CoG were closed to each other in both the left and right hemispheres. In the cLBP group, these two locations were next to each other in the right hemisphere but discrete in the left hemisphere. In the cLBP group, the cortical motor map of TVA and MF were mutually symmetric in five out of eleven (45.5%) subjects and leftward asymmetric in four out of ten (40.0%) subjects. Conclusions. Neural representations of TVA and MF muscles were closely organized in both the right and left motor cortices in the healthy group but were discretely organized in the left motor cortex in the cLBP group. This provides strong support for the neural basis of pathokinesiology and clinical treatment of cLBP.

Background Studies have demonstrated that elderly people with low back pain (LBP) may have poor postural control compared to healthy older adults. Poor postural control is associated with poor balance performance and a high risk of serious falls. A variety of training strategies are proposed for LBP therapy, particularly core stabilization training. But this treatment for older people with LBP remains unclear. Methods 31 participants were randomly placed in a core stability training group (TG, n = 15) and a control group (CG, n = 16). The participants in the training group were required to complete 4 sets of core stability training and conventional physiotherapy 4 times per week for 4 weeks, whereas the participants in the control group only completed physiotherapy 4 times per week for 4 weeks. Ultrasound imaging was used to measure transverse abdominal muscle (TrA) thickness before and after the intervention. A 10-cm visual analog scale (VAS), the Oswestry Disability Index (ODI), and mobility functions were applied before and after the intervention. Data are reported as the median and range and were compared using two-way repeated-measures ANOVA,t-tests and chi-squared tests. P < 0.05 was considered significant in all statistical tests. Results After intervention, there was a statistically significant difference in scores in the intervention group, especially for VAS, ODI, timed up-and-go,10-m walking and the four-square step test. TrA thickness was increased after core stability training, which was not observed in the control group. Conclusion Core stability training is an effective intervention for older women with LBP.

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