The development of the Dutch version of the Fremantle Back Awareness Questionnaire

Background: Disturbed body perception may play a role in the aetiology of chronic low back pain (LBP). The Fremantle Back Awareness Questionnaire (FreBAQ) is currently the only self-report questionnaire to assess back-specific body perception in individuals with LBP. Objectives: To perform a cross-cultural adaptation of the FreBAQ into Dutch. Design: Psychometric study. Methods: A Dutch version of the FreBAQ was generated through forward-backward translation, and was completed by 73 patients with LBP and 73 controls to assess discriminant validity. Structural validity was assessed by principal component analysis. Internal consistency was assessed by the Cronbach\u27s alpha coefficient. Construct validity was assessed by examining the relationship with clinical measures (Numerical Rating Scale pain, Oswestry Disability Index (ODI), Tampa Scale for Kinesiophobia). Test-retest reliability was assessed in a subgroup (n = 48 with LBP and 48 controls) using intraclass correlation coefficients (ICC), standard error of measurement (SEM) and minimal detectable change (MDC 95%) Results: The Dutch FreBAQ showed one component with eigenvalue \u3e2. Cronbach\u27s alpha values were respectively 0.82 and 0.73 for the LBP and control group. ICC values were respectively 0.69 and 0.70 for the LBP and control group. In the LBP group, the SEM was 3.9 and the MDC (95%) was 10.8. The LBP group (ODI 22 ± 21%) scored significantly higher on the Dutch FreBAQ than the control group (ODI 0%) (11 ± 7 vs. 3 ± 9, p \u3c 0.001). Within the LBP group, higher Dutch FreBAQ scores correlated significantly with higher ODI scores (rho = 0.30, p = 0.010), although not with pain (rho = 0.10, p = 0.419) or kinesiophobia (r = 0.14, p = 0.226). Conclusions: The Dutch version of the FreBAQ can be considered as unidimensional and showed adequate internal consistency, sufficient test-retest reliability and adequate discriminant and construct validity in individuals with and without LBP. It can improve our understanding on back-specific perception in the Dutch-speaking population with LBP

Postural strategy and back muscle oxygenation during inspiratory muscle loading.

Most healthy individuals show a multisegmental control strategy during challenging standing conditions, whereas others show a rigid ankle-steered strategy, which is assumed as suboptimal. Respiratory-demanding tasks exert a perturbing effect on balance, although the underlying mechanisms remain poorly understood. The purpose of this study was to investigate whether inspiratory resistive loading (IRL) affects postural strategy, back muscle oxygenation, and blood volume during postural control

Inspiratory muscle training affects proprioceptive use and low back pain.

We have shown that individuals with recurrent nonspecific low back pain (LBP) and healthy individuals breathing against an inspiratory load decrease their reliance on back proprioceptive signals in upright standing. Because individuals with LBP show greater susceptibility to diaphragm fatigue, it is reasonable to hypothesize that LBP, diaphragm dysfunction, and proprioceptive use may be interrelated. The purpose of this study was to investigate whether inspiratory muscle training (IMT) affects proprioceptive use during postural control in individuals with LBP

The neural basis of complex postural tasks in individuals with and without non-specific low back pain

De neural basis of complex postural tasks in individuals with and without non-specific low back pain Sensorimotor control is the ongoing integration of sensory and motor signals in the central nervous system, in order to provide an appropriate motor output that corresponds to all internal and external demands. To make an accurate assessment of these demands, an efficient transmission and processing of sensory and motor information across the brain is required. This optimal sensorimotor control is crucial in daily living, e.g., for postural control and the coordination of smooth and accurate movements. Postural control is the ability to maintain body posture by adapting to the environmental demands. The ability to select and weight sensory input from the visual, vestibular and proprioceptive systems, adaptively to these environmental demands, is crucial for optimal postural control. Proprioception is a primary sense for postural control and can be defined as the unconscious perception of movement and spatial orientation arising from stimuli within the body . When postural demands change, the postural control system must identify and rely upon proprioceptive input that provides the most reliable information. Weighting between locations of proprioceptive origin is crucial in situations in which proprioceptive signals from specific body parts are considered less reliable. For example, during standing on an unstable support surface, ankle muscle proprioception becomes less reliable due to the mismatch between the ankle joint angle change and postural sway. Therefore, optimal proprioceptive postural control depends on the central identification and processing of relevant and reliable afferent sensory signals to provide an appropriate efferent motor output adapted to the postural demands. Previous research mainly focused on postural control during standing and/or sitting. However, optimal postural and sensorimotor control is also required during the coordination of smooth and accurate movements. One of these movements that requires both sensorimotor and (proprioceptive) postural control is rising up and sitting down on a chair, usually called the sit-to-stand-to-sit (STSTS) movement. The STSTS performance is known to place a high demand on the postural system because it requires a coordinated vertical and horizontal center of mass displacement. By performing the STSTS task on an unstable support surface, an additional complexity is added to the task because the unstable support surface forces additional weighting of proprioceptive signals due to the decreased reliability of proprioceptive information from the ankle region. Therefore, this task is a prototype of a complex postural task, requiring integration of sensorimotor information in the brain. Changes in postural control, which can for example be reflected in the proprioceptive weighting capacity and the sit-to-stand-to-sit performance, have been studied as possible underlying mechanisms ofnon-specific low back pain (NSLBP). Low back pain has become a well-known and important health problem in Western society, and it seems to be extending worldwide. Despite many efforts in the development of treatment strategies, effects of current low back pain interventions are rather small. Therefore, the identification of the underlying mechanisms and causes of NSLBP was recently considered as one of the priorities in low back pain research. Many studies in the field of postural control and NSLBP have focused on motor output. However, optimal postural control depends on the coactivation of many brain regions, which have to operate as a coordinated network to achieve the optimal motor output. The scope of this doctoral project was to investigate the neural basis of complex postural tasks. More specifically, to investigate whether there is a relationship between characteristics of the brain and the performance of complex postural tasks. In addition, potential differences in brain structure and function between individuals with NSLBP and healthy controls were examined. These objectives were realized through four studies. In Chapter 1, the association between the capacity to weight proprioceptive signals for postural control and the integrity of individual white matter pathways were observed. In addition, potential differences in sensorimotor white matter microstructure between individuals with NSLBP and healthy controls were evaluated. The results of this study showed that a decreased integrity of the superior cerebellar peduncle was associated with a lower proprioceptive weighting capacity in the individuals with NSLBP. In addition, a tendency to decreased integrity of the left superior cerebellar peduncle in individuals with NSLBP compared to healthy controls was found. These findings suggest that the superior cerebellar peduncle is an important sensorimotor pathway for proprioceptive signals during postural control in individuals with NSLBP. This was the first study that explored the neural basis of the proprioceptive weighting capacity in individuals with NSLBP. The following studies focused on the dynamic postural task, more specifically, the performance of five consecutive STSTS movements. The findings revealed that individuals with NSLBP required significantly more time to perform the STSTS task on stable and unstable support surface compared to healthy controls. Chapter 2 concentrated on characterizing the regional and global structure of the whole brain network. The findings revealed that both global and regional network measures were associated with the performance of the STSTS task in individuals with NSLBP and healthy controls. More specifically, decreased mean degree, decreased nodal degree of the right calcarine gyrus and decreased local efficiency of the left caudate nucleus were associated with a longer duration to perform five consecutive STSTS movements on unstable support surface. These results suggest that optimal brain connectivity from a network perspective is crucial for the performance of a complex postural task with an important role for areas related to the processing of sensory signals. In contrast to the first two chapters, which focused on white matter characteristics, Chapter 3 explored the structural gray matter characteristics of individuals with NSLBP and healthy controls. The results showed that lower STSTS performance on unstable support surface was associated with decreased cortical surface area of the superior parietal cortex and the frontal pole in individuals with NSLBP and healthy controls, while cortical thinning of the rostral anterior cingulate was correlated with lower STSTS performance on stable support surface. In addition, only measures of cortical thickness were positively correlated with the level of pain intensity in individuals with NSLBP. These findings suggest that cortical surface area and cortical thickness show a distinct association with postural performance and pain. In addition, the results emphasize the importance of evaluating non-volumetric parameters next to cortical volume to provide a more complete understanding of complex postural tasks. Chapter 4 complements the first three chapters on structural data, by describing functional differences in the sensorimotor network. Compared to healthy controls, the individuals with NSLBP showed differences, primarily decreases, in resting-state functional connectivity in brain areas related to the integration of sensory and/or motor signals for adequate movements. These findings suggest a significant reorganization of the sensorimotor resting-state network in individuals with NSLBP. The results of this doctoral project show that areas involved in the integration of sensorimotor information (e.g., somatosensory and visual information) and cognitive information are associated with the performance of complex postural tasks. This suggests that the ability to centrally process and transmit these signals in the brain is important for optimal postural performance. These conclusions are based on both region-specific measures and measures of network connectivity, emphasizing the importance of both the integrity of the individual regions and optimal communication between the regions. Remarkably, most areas were related to the processing of sensory information, before the motor output was generated, reinforcing the importance of the sensory part in postural control. In addition, subtle group differences in the characteristics of brain regions related to sensorimotor (e.g., somatosensory and visual) and cognitive processing were observed. In conclusion, these results increase our knowledge on the neural basis of complex postural tasks, however further research is necessary to confirm these findings and to further investigate what drives postural control and NSLBP.TABLE OF CONTENTS Dankwoord General Introduction Chapter 1 Microstructural integrity of the superior cerebellar peduncle is associated with an impaired proprioceptive weighting capacity in individuals with non-specific low back pain Chapter 2 The role of the caudate nucleus and primary visual cortex in the sit-to-stand-to-sit task in individuals with non-specific low back pain and healthy controls: a diffusion MRI based network analysis Chapter 3 Associations between measures of structural morphometry and sit-to-stand-to-sit performance in individuals with non-specific low back pain and healthy controls Chapter 4 Resting-state functional connectivity of the sensorimotor network in individuals with non-specific low back pain and the association with the sit-to-stand-to-sit task General Discussion Summary Samenvatting Bijstellingen About the author Publicationsnrpages: 142status: publishe

Structural brain connectivity and the sit-to-stand-to-sit performance in individuals with non-specific low back pain: A diffusion MRI based network analysis

Individuals with non-specific low back pain (NSLBP) show an impaired sensorimotor control. They need significantly more time to perform five consecutive sit-to-stand-to-sit (STSTS) movements compared to healthy controls. Optimal sensorimotor control depends on the co-activation of many brain regions, which have to operate as a co-ordinated network to achieve correct motor output. Therefore, the examination of brain connectivity from a network perspective is crucial for understanding the factors that drive sensorimotor control. In the current study, potential alterations in structural brain networks of individuals with NSLBP and the correlation with the performance of the STSTS task were investigated. Seventeen individuals with NSLBP and 17 healthy controls were instructed to perform five consecutive STSTS movements as fast as possible. In addition, data of diffusion magnetic resonance imaging were acquired and analyzed using a graph theoretical approach. Results showed that individuals with NSLBP needed significantly more time to perform the STSTS task compared to healthy controls (p < 0.05). Both groups exhibited small-world properties in their structural networks. However, local efficiency was significantly decreased in the NSLBP patients compared with controls (p < 0.05, FDR corrected). Moreover, global efficiency was significantly correlated with the sensorimotor task performance within the NSLBP group (r = -0.73, p = 0.002). Our data show disrupted network organization of white matter networks in patients with NSLBP, which may contribute to their persistent pain and motor disabilities.status: publishe

An fMRI-compatible pneumatic vibrator to stimulate muscle proprioceptors: first results on reliability and validity

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Young individuals with a more ankle-steered proprioceptive control strategy may develop mild non-specific low back pain

Altered proprioceptive postural control has been demonstrated in people with non-specific low back pain (LBP). However, the cause-effect relation remains unclear. Therefore, more prospective studies are necessary. Proprioceptive postural control of 104 subjects was evaluated at baseline using a force plate and with application of vibration stimulation on ankle and back muscles. Spinal postural angles were measured with digital photographs. Psychosocial variables and physical activity were registered using questionnaires. Ninety subjects were followed over two years concerning their LBP status, 14 were lost to follow-up. Four distinct groups were determined after two years based on pain and disability scores: never LBP, no LBP at intake with future mild LBP, mild LBP at intake with no further LBP, LBP at intake with further episodes of mild LBP. Risk factors for developing or sustaining LBP were calculated using logistic regression analysis. A more ankle-steered proprioceptive postural control strategy in upright standing increased the risk for developing or having recurrences of mild LBP within two years (Odds: 3.5; 95% CI: 1.1–10.8; p < 0.05). Increased postural sway, altered spinal postural angles, psychosocial and physical activity outcomes were not identified as risk factors for future mild LBP. These findings could contribute to improving the prevention and rehabilitation of LBP.publisher: Elsevier articletitle: Young individuals with a more ankle-steered proprioceptive control strategy may develop mild non-specific low back pain journaltitle: Journal of Electromyography and Kinesiology articlelink: http://dx.doi.org/10.1016/j.jelekin.2014.10.013 content_type: article copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.status: publishe

Associations between measures of structural brain connectivity and the sit-to-stand-to-sit performance in individuals with non-specific low back pain and healthy controls: a diffusion MRI based network analysis

BACKGROUND AND AIM Individuals with non-specific low back pain (NSLBP) show an impaired sensorimotor control. They need significantly more time to perform five consecutive sit-to-stand-to-sit (STSTS) movements compared to healthy controls. Optimal sensorimotor control depends on the co-activation of many brain regions, which have to operate as a co-ordinated network to achieve correct motor output. Therefore, the examination of brain connectivity from a network perspective is crucial for understanding the factors that drive sensorimotor control. In addition, since NSLBP is an important socio-economic health problem and since the current treatment of NSLBP provides only modest short-term success, research related to the mechanisms and causes of NSLBP is recently considered as one of the priorities in NSLBP research. Therefore, potential alterations in structural brain networks of individuals with NSLBP and the correlation with the performance of the STSTS task were investigated. METHODS Seventeen individuals with NSLBP and 17 healthy controls were instructed to perform five consecutive STSTS movements as fast as possible. Based on the center of pressure displacement, the total duration of the STSTS task was determined. In addition, data of diffusion magnetic resonance imaging (b-value of 1300 s/mm², 60 non-collinear directions and an average of 5 b0-images) were acquired and analyzed using a graph theoretical approach. RESULTS Results showed that individuals with NSLBP needed significantly more time to perform the STSTS task compared to healthy controls (p= 0.002). In addition, an increased duration of this STSTS task was associated with decreased mean degree (unstable support surface: r= -0.53, p= 0.002), decreased nodal degree of the primary visual cortex (stable support surface: r= -0.56, p= 0.001; unstable support surface: r= -0.55, r= 0.001) and decreased local efficiency of the caudate nucleus (unstable support surface: r= -0.50, p= 0.003) across the total group. However, no significant group differences in the network measures were observed (p> 0.0006). CONCLUSIONS Both global and regional network measures were associated with the performance of the STSTS task. At regional level, the decreased nodal degree of the primary visual cortex and the decreased local efficiency of the caudate nucleus were correlated with a longer duration to perform five consecutive STSTS movements. These findings suggest that the connectivity of these sensorimotor areas, related to the processing of sensory signals, plays an important role in sensorimotor control. Moreover, the findings suggest that optimal brain connectivity from a network perspective is crucial for sensorimotor control.status: publishe

The effect of acute back muscles fatigue on postural control in people with and without recurrent low back pain

Back muscle fatigue decreases the postural stability during quiet standing, but it is not known whether this fatigue-induced postural instability is due to an altered proprioceptive postural control strategy. Therefore, the aim of the study was to evaluate if acute back muscle fatigue may be a mechanism to induce or sustain a suboptimal proprioceptive postural control strategy in people with and without recurrent low back pain (LBP). Postural sway was evaluated on a force platform in 16 healthy subjects and 16 individuals with recurrent LBP during a control (Condition 1) and a back muscle fatigue condition (Condition 2). Back muscle fatigue was induced by performing a modified Biering-Sørensen test. Ankle and back muscle vibration, a potent stimulus for muscle spindles, was used to differentiate proprioceptive postural control strategies during standing on a stable and unstable support surface, where the latter was achieved by placing a foam pad under the feet. Ankle signals were predominantly used for postural control in all subjects although, in each condition, their influence was greater in people with LBP compared to healthy subjects (p < 0.001). The latter group adapted their postural control strategy when standing on an unstable surface so that input from back muscles increased (p < 0.001). However, such adaptation was not observed when the back muscles were fatigued. Furthermore, people with LBP continued to rely strongly on ankle proprioception regardless of the testing conditions. In conclusion, these findings suggest that impaired back muscle function, as a result of acute muscle fatigue or pain, may lead to an inability to adapt postural control strategies to the prevailing conditions.status: publishe

Proprioceptive postural control and functional outcome after first-time lumbar micro-discectomy: the effect of early individualized physical therapy

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