The relationship between pain-related fear and lumbar flexion during natural recovery from low back pain

Altered Movement Coordination during Functional Reach Tasks in Patients with Chronic Low Back Pain and Its Relationship to Numerical Pain Rating Scores

Identifying the effects of pain catastrophizing on movement patterns in people with chronic low back pain (CLBP) has important clinical implications for treatment approaches. Prior research has shown people with CLBP have decreased lumbar-hip ratios during trunk flexion movements, indicating a decrease in the contribution of lumbar flexion relative to hip flexion during trunk flexion. In this study, we aim to explore the relationship between pain catastrophizing and movement patterns during trunk flexion in a CLBP population. Participants with CLBP (N = 98, male = 59, age = 39.1 ± 13.0) completed a virtual reality standardized reaching task that necessitated a progressively larger amount of trunk flexion. Specifically, participants reached for four virtual targets to elicit 15°, 30°, 45°, and 60° trunk flexion in the mid-sagittal plane. Lumbar flexion was derived from the motion data. Self-report measures of numerical pain ratings, kinesiophobia, and pain catastrophizing were obtained. Pain catastrophizing leads to decreased lumbar flexion angles during forward reaching. This effect is greater in females than males.

Lower individual alpha frequency in individuals with chronic low back pain and fear of movement

ABSTRACT

Significant progress has been made in linking measures of individual alpha frequency (IAF) and pain. A lower IAF has been associated with chronic neuropathic pain and with an increased sensitivity to pain in healthy young adults. However, the translation of these findings to chronic low back pain (cLBP) are sparse and inconsistent. To address this limitation, we assessed IAFs in a cohort of 70 individuals with cLBP, implemented 3 different IAF calculations, and separated cLBP subjects based on psychological variables. We hypothesized that a higher fear movement in cLBP is associated with a lower IAF at rest. A total of 10 minutes of resting data were collected from 128 electroencephalography channels. Our results offer 3 novel contributions to the literature. First, the high fear group had a significantly lower peak alpha frequency. The high fear group also reported higher pain and higher disability. Second, we calculated individual alpha frequency using 3 different but established methods; the effect of fear on individual alpha frequency was robust across all methods. Third, fear of movement, pain intensity, and disability highly correlated with each other and together significantly predicted IAF. Our findings are the first to show that individuals with cLBP and high fear have a lower peak alpha frequency.

The clinical course of acute, subacute and persistent low back pain: a systematic review and meta-analysis

BACKGROUND

Understanding the clinical course of low back pain is essential to informing treatment recommendations and patient stratification. Our aim was to update our previous systematic review and meta-analysis to gain a better understanding of the clinical course of acute, subacute and persistent low back pain.

METHODS

To update our 2012 systematic review and meta-analysis, we searched the Embase, MEDLINE and CINAHL databases from 2011 until January 2023, using our previous search strategy. We included prospective inception cohort studies if they reported on participants with acute (< 6 wk), subacute (6 to less than 12 wk) or persistent (12 to less than 52 wk) nonspecific low back pain at study entry. Primary outcome measures included pain and disability (0-100 scale). We assessed risk of bias of included studies using a modified tool and assessed the level of confidence in pooled estimates using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool. We used a mixed model design to calculate pooled estimates (mean, 95% confidence interval [CI]) of pain and disability at 0, 6, 12, 26 and 52 weeks. We treated time in 2 ways: time since study entry (inception time uncorrected) and time since pain onset (inception time corrected). We transformed the latter by adding the mean inception time to the time of study entry.

RESULTS

We included 95 studies, with 60 separate cohorts in the systematic review (n = 17 974) and 47 cohorts (n = 9224) in the meta-analysis. Risk of bias of included studies was variable, with poor study attrition and follow-up, and most studies did not select participants as consecutive cases. For the acute pain cohort, the estimated mean pain score with inception time uncorrected was 56 (95% CI 49-62) at baseline, 26 (95% CI 21-31) at 6 weeks, 22 (95% CI 18-26) at 26 weeks and 21 (95% CI 17-25) at 52 weeks (moderate-certainty evidence). For the subacute pain cohort, the mean pain score was 63 (95% CI 55-71) at baseline, 29 (95% CI 22-37) at 6 weeks, 29 (95% CI 22-36) at 26 weeks and 31 (95% 23-39) at 52 weeks (moderate-certainty evidence). For the persistent pain cohort, the mean pain score was 56 (95% CI 37-74) at baseline, 48 (95% CI 32-64) at 6 weeks, 43 (95% CI 29-57) at 26 weeks and 40 (95% CI 27-54) at 52 weeks (very low-certainty evidence). The clinical course of disability was slightly more favourable than the clinical course of pain.

INTERPRETATION

Participants with acute and subacute low back pain had substantial improvements in levels of pain and disability within the first 6 weeks ( moderate-certainty evidence); however, participants with persistent low back pain had high levels of pain and disability with minimal improvements over time (very low-certainty evidence). Identifying and escalating care in individuals with subacute low back pain who are recovering slowly could be a focus of intervention to reduce the likelihood of transition into persistent low back pain.

PROTOCOL REGISTRATION

PROSPERO - CRD42020207442.

Determinants of outcomes for patients with chronic low back pain and fear-avoidance beliefs following treatment with specific stabilisation exercises

BACKGROUND

Specific stabilisation exercises (SSE) can combat the debilitating effects of chronic non-specific low back pain (CLBP), improve disability, pain and fear-avoidance beliefs (FAB).

OBJECTIVE

To elicit the determinants of outcome in patients with CLBP with associated FABs after treatment with SSE.

METHOD

Twenty-nine patients (20 females) with CLBP were classified using FAB questionnaire into high or low Work and Physical Activity (PA) subscales. After 4-week treatment, evaluations were done for pain, disability and lumbar spine active range of motion (AROM). Data was analysed exploratory-descriptively with a significance level set at p< 0.05.

RESULTS

Participants were aged 55.24 ± 11.91 years. They scored 19 (65.5%) and 5 (17.2%) respectively on Work and PA subscales. The post-intervention evaluation showed significant differences in all outcomes, but no significant difference between patients with high or low FAB scores for both subscales. PA scores correlated significantly with pain while work scores correlated significantly with disability. Participants' gender predicted disability, pain and AROM with moderate to large effect sizes.

CONCLUSION

SSE can potentially improve disability, pain and range of motion for patients with chronic low back pain regardless of FABQ status. Gender and baseline patient status are potential determinants of outcome of treatment using SSE.

The relationships between spinal amplitude of movement, pain and disability in low back pain: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The role of spinal movement alterations in low back pain (LBP) remains unclear. This systematic review and meta-analyses examined the relationships between spinal amplitude of movement, disability and pain intensity in patients with LBP.

DATABASES AND DATA TREATMENT

We searched PubMed, CINAHL, Embase, Pedro and Web of Science for relevant articles until 14th March 2023. Risk of bias was assessed with the Quality in Prognostic Studies Tool. We analysed the relationships between amplitude of movement, disability and pain intensity with standard correlational meta-analyses and meta-analytic structural equation modelling (MASEM) in cross-sectional and longitudinal data.

RESULTS

A total of 106 studies (9001 participants) were included. In cross-sectional data, larger amplitude of movement was associated with lower disability (pooled coefficient: -0.25, 95% confidence interval: [-0.29 to -0.21]; 69/5899 studies/participants) and pain intensity (-0.13, [-0.17 to -0.09]; 74/5806). An increase in amplitude of movement was associated with a decrease in disability (-0.23, [-0.31 to -0.15]; 33/2437) and pain intensity (-0.25, [-0.33 to -0.17]; 38/2172) in longitudinal data. MASEM revealed similar results and, in addition, showed that amplitude of movement had a very small influence on the pain intensity-disability relationship.

CONCLUSIONS

These results showed a significant but small association between amplitude of movement and disability or pain intensity. Moreover, they demonstrated a direct association between an increase in amplitude of movement and a decrease in pain intensity or disability, supporting interventions aiming to reduce protective spinal movements in patients with LBP.

SIGNIFICANCE

The large meta-analyses performed in this work revealed an association between reductions in spinal amplitude of movement and increased levels of disability and pain intensity in people with LBP. Moreover, it highlighted that LBP recovery is associated with a reduction in protective motor behaviour (increased amplitude of movement), supporting the inclusion of spinal movement in the biopsychosocial understanding and management of LBP.

The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications

Changes in back muscle function and structure are highly prevalent in patients with chronic low back pain (CLBP). Since large heterogeneity in clinical presentation and back muscle dysfunctions exists within this population, the potential role of back muscle dysfunctions in the persistence of low back pain differs between individuals. Consequently, interventions should be tailored to the individual patient and be based on a thorough clinical examination taking into account the multidimensional nature of CLBP. Considering the complexity of this process, we will provide a state-of-the-art update on back muscle dysfunctions in patients with CLBP and their implications for treatment. To this end, we will first give an overview of (1) dysfunctions in back muscle structure and function, (2) the potential of exercise therapy to address these dysfunctions, and (3) the relationship between changes in back muscle dysfunctions and clinical parameters. In a second part, we will describe a framework for an individualised approach for back muscle training in patients with CLBP.

Get Your Head in the Game: A Replicated Single-Case Experimental Design Evaluating the Effect of a Novel Virtual Reality Intervention in People With Chronic Low Back Pain

Chronic low back pain (CLBP) is a leading cause of disability worldwide. Contemporary treatment of CLBP is suboptimal, with small-moderate effect sizes and high relapse rates. Virtual reality (VR) is an increasingly accessible technology that can improve adherence to exercise programs through gamification. Using VR to facilitate exercise adherence and enjoyment may improve the clinical outcomes. This study aimed to evaluate the effects of a gamified VR graded activity intervention in people with CLBP, using commercially available and bespoke VR programs. A sequentially replicated, multiple-baseline, randomized AB single-case experimental design was undertaken in 10 people with CLBP. Outcomes were assessed daily and included pain intensity (primary) and pain catastrophizing, pain-related fear, and anxiety/worry (secondary). The effect of the intervention on the primary outcome was evaluated using a multilevel-model, nonparametric randomization test. The VR graded activity intervention resulted in a significant reduction in pain intensity (effect estimate = -1.0, standard error = .27, P < .0011) with 4 participants achieving ≥30% pain reduction (minimum important change). There was a significant effect of the intervention on pain catastrophizing but not pain-related fear or anxiety/worry measures. These findings provide preliminary support for a VR graded activity program to reduce pain in people with CLBP. PERSPECTIVE: This novel, VR graded activity intervention reduced pain intensity and catastrophizing in people with CLBP. The intervention also had high adherence and enjoyment. Given that this intervention involved 2 freely available VR programs, it can be easily translated into clinical practice.

Task-specific fear rather than general kinesiophobia assessment is associated with kinematic differences in chronic low back pain during lumbar flexion: a preliminary investigation

Introduction

Kinematic data obtained during a movement task by individuals with chronic low back pain seem to be related to pain-related fear. General kinesiophobia assessments, such as Tampa Scale for Kinesiophobia, are often used to assess pain-related fear. However, these questionnaires could suffer from a lack of sensitivity and do not measure the fear of specific movements.

Objectives

The purpose of this study was to investigate whether the task-specific assessment of pain-related fear exhibits a closer association with trunk kinematics during lumbar flexion compared with the general kinesiophobia in individuals with chronic low back pain.

Methods

We assessed pain-related factors, task-specific fear, and Tampa Scale for Kinesiophobia-11 scores of 51 company employees. The lumbar angle during a lumbar flexion task was recorded by 2 wireless Axivity Ax3 accelerometers attached to the subject's spinous process (L3) and sacral spine (S2). Only task-specific fear was evaluated after the lumbar flexion task. We calculated the maximum lumbar flexion angle (°) and the peak angular velocity of lumbar flexion/return from flexion (°/s2). We conducted a hierarchical multiple linear regression analysis to determine variance explained in lumbar flexion task performance by task-specific fear after controlling for demographic, pain, and general kinesiophobia.

Results

The results showed that task-specific fear was associated with the peak angular velocity of lumbar return from flexion (R 2 adj. = 0.36, P < 0.01) and lumbar flexion (R 2 adj. = 0.3, P = 0.01).

Discussion

Our results suggest that clinicians should consider the potential added value of task-specific fear assessment over the sole use of conventional kinesiophobia assessment.

Association of pain-related threat beliefs and disability with postural control and trunk motion in individuals with low back pain: a systematic review and meta-analysis

PURPOSE

Low back pain (LBP) individuals with high levels of fear of pain might display changes in motor behavior, which leads to disability. This study aimed to systematically review the influence of pain-related threat beliefs or disability on trunk kinematic or postural control in LBP.

METHOD

Eight electronic databases were searched from January 1990 to July 1, 2020. Meta-analysis using random-effect model was performed for 18 studies on the association between pain-related threat beliefs or disability and lumbar range of motion. Pearson r correlations were used as the effect size.

RESULT

Negative correlations were observed between lumbar range of motion (ROM) and pain-related threat beliefs (r = - 0.31, p < 0.01, 95% CI: - 0.39, - 0.24) and disability (r =  - 0.24, p < 0.01, 95% CI: - 0.40, - 0.21). Nonsignificant correlations were reported between pain-related threat beliefs and center of pressure parameters during static standing in 75% of the studies. In 33% of the studies, moderate negative correlations between disability and postural control were observed.

CONCLUSION

Motor behaviors are influenced by several factors, and therefore, the relatively weak associations observed between reduced lumbar ROM with higher pain-related threat beliefs and perceived disability, and postural control with disability are to be expected. This could aid clinicians in the assessment and planning rehabilitation interventions.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

A Virtual Reality Game Suite for Graded Rehabilitation in Patients With Low Back Pain and a High Fear of Movement: Within-Subject Comparative Study

BACKGROUND

Complex movement pathologies that are biopsychosocial in nature (eg, back pain) require a multidimensional approach for effective treatment. Virtual reality is a promising tool for rehabilitation, where therapeutic interventions can be gamified to promote and train specific movement behaviors while increasing enjoyment, engagement, and retention. We have previously created virtual reality-based tools to assess and promote lumbar excursion during reaching and functional gameplay tasks by manipulating the position of static and dynamic contact targets. Based on the framework of graded exposure rehabilitation, we have created a new virtual reality therapy aimed to alter movement speed while retaining the movement-promoting features of our other developments.

OBJECTIVE

This study aims to compare lumbar flexion excursion and velocity across our previous and newly developed virtual reality tools in a healthy control cohort.

METHODS

A total of 31 healthy participants (16 males, 15 females) took part in 3 gamified virtual reality therapies (ie, Reachality, Fishality, and Dodgeality), while whole-body 3D kinematics were collected at 100 Hz using a 14-camera motion capture system. Lumbar excursion, lumbar flexion velocity, and actual target impact location in the anterior and vertical direction were compared across each virtual reality task and between the 4 anthropometrically defined intended target impact locations using separate 2-way repeated measures analysis of variance models.

RESULTS

There was an interaction between game and impact height for each outcome (all P<.001). Post-hoc simple effects models revealed that lumbar excursion was reduced during Reachality and Fishality relative to that during Dodgeality for the 2 higher impact heights but was greater during Reachality than during Fishality and Dodgeality for the lowest impact height. Peak lumbar flexion velocity was greater during Dodgeality than during Fishality and Reachality across heights. Actual target impact locations during Dodgeality and Fishality were lower relative to those during Reachality at higher intended impact locations but higher at lower intended impact locations. Finally, actual target impact location was further in the anterior direction for Reachality compared to that for Fishality and for Fishality relative to that for Dodgeality.

CONCLUSIONS

Lumbar flexion velocity was reduced during Fishality relative to that during Dodgeality and resembled velocity demands more similar to those for a self-paced reaching task (ie, Reachality). Additionally, lumbar motion and target impact location during Fishality were more similar to those during Reachality than to those during Dodgeality, which suggests that this new virtual reality game is an effective tool for shaping movement. These findings are encouraging for future research aimed at developing an individualized and graded virtual reality intervention for patients with low back pain and a high fear of movement.

Task-specific fear influences abnormal trunk motor coordination in workers with chronic low back pain: a relative phase angle analysis of object-lifting

Background

Pain-related fear influences impaired trunk movement (e.g., limited movement of range and velocity), but it is unclear how fear relates to trunk motor coordination (e.g., a more “in-phase” upper-lower trunk motion pattern). We conducted the present study to: (1) identify the motor coordination pattern of the in-phase upper-lower lumbar movements during the lifting, and (2) determine how pain-related fear is related to the trunk coordination pattern in workers with chronic low back pain (CLBP).

Methods

We examined 31 male workers with CLBP (CLBP group) and 20 healthy controls with no history of CLBP (HC group). The movement task was lifting a box, the weight of which was 10, 30%, or 50% of the subject’s body weight. We used a 3D motion capture system to calculate the mean absolute relative phase angle (MARP) angle as an index of coordination and the mean deviation phase (DP) as an index of variability. We used a numerical rating scale to assess the subjects’ task-specific fear.

Results

The MARP angle during trunk extension movement in the 50% condition was significantly decreased in the CLBP group compared to the HCs; i.e., the upper lumbar movement was more in-phase with the lower lumbar movement. The hierarchical multiple regression analysis results demonstrated that a decreased MARP angle was associated with high task-specific fear.

Conclusions

A more ‘in-phase’ upper-lower lumbar movement pattern was predicted by task-specific fear evoked when performing a work-related activity. Our findings suggest that an intervention for task-specific fear may be necessary to improve an individual’s impaired trunk motor coordination.

The Relationship Between Pain-Related Threat and Motor Behavior in Nonspecific Low Back Pain: A Systematic Review and Meta-Analysis

OBJECTIVE

Although pain-related fear and catastrophizing are predictors of disability in low back pain (LBP), their relationship with guarded motor behavior is unclear. The aim of this meta-analysis was to determine the relationship between pain-related threat (via pain-related fear and catastrophizing) and motor behavior during functional tasks in adults with LBP.

METHODS

This review followed PRISMA guidelines. MEDLINE, Embase, PsychINFO, and CINAHL databases were searched to April 2021. Included studies measured the association between pain-related fear or pain catastrophizing and motor behavior (spinal range of motion, trunk coordination and variability, muscle activity) during movement in adults with nonspecific LBP. Studies were excluded if participants were postsurgery or diagnosed with specific LBP. Two independent reviewers extracted all data. The Newcastle-Ottawa Scale was used to assess for risk of bias. Correlation coefficients were pooled using the random-effects model.

RESULTS

Reduced spinal range of motion during flexion tasks was weakly related to pain-related fear (15 studies, r = -0.21, 95% CI = -0.31 to -0.11) and pain catastrophizing (7 studies, r = -0.24, 95% CI = -0.38 to -0.087). Pain-related fear was unrelated to spinal extension (3 studies, r = -0.16, 95% CI = -0.33 to 0.026). Greater trunk extensor muscle activity during bending was moderately related to pain-related fear (2 studies, r = -0.40, 95% CI = -0.55 to -0.23). Pain catastrophizing, but not fear, was related to higher trunk activity during gait (2 studies, r = 0.25, 95% CI = 0.063 to 0.42). Methodological differences and missing data limited robust syntheses of studies examining muscle activity, so these findings should be interpreted carefully.

CONCLUSION

This study found a weak to moderate relationship between pain-related threat and guarded motor behavior during flexion-based tasks, but not consistently during other movements.

IMPACT

These findings provide a jumping-off point for future clinical research to explore the advantages of integrated treatment strategies that target both psychological and motor behavior processes compared with traditional approaches.

The Impact of Reassurance on Musculoskeletal (MSK) Pain: A Qualitative Review

BACKGROUND

The reassurance provided during patient-therapist interactions is significantly associated with psychosocial outcomes, including fear and increased confidence. Currently, there are no available reviews that discuss the impact of reassurance for patients with musculoskeletal (MSK) pain. The aim of the present review was to qualitatively synthesize themes around reassurance mechanisms, and the impact during the interaction between patients with MSK pain and therapists. A systematic search strategy was undertaken. Studies were included if they were qualitative or mixed methods studies, examining the patient-therapist consultation, in any MSK clinical setting, with any health care professional, for adult patients with acute to chronic MSK pain. A thematic synthesis was conducted and supported by a particular assessment using CERQual.

RESULTS

Twenty-four studies were included (451 patients). Certain themes that related to both positive and negative outcomes of reassurance were identified as well as themes that illustrate the mechanisms causative of the outcomes. Using CerQual, we identified the most supported outcomes.

CONCLUSIONS

Effective reassurance includes affectionate interactions such as therapeutic relationship building and interpersonal skills, an individualized patient-centered approach, education and the provision of self-management strategies. It should be noted that some interactions that use pathoanatomic models led patients to misinterpret the information provided, this created feelings of fear.

The flexion relaxation phenomenon in nonspecific chronic low back pain: prevalence, reproducibility and flexion-extension ratios. A systematic review and meta-analysis

PURPOSE

The flexion relaxation phenomenon (FRP) is characterized by the reduction of paraspinal muscle activity at maximum trunk flexion. The FRP is reported to be altered (persistence of spinal muscle activity) in nonspecific chronic low back pain (NSCLBP) and is considered a promising biomarker. The aim of this systematic review was to synthetize current knowledge on FRP in the NSCLBP population regarding prevalence, the reliability of FRP measurement using surface electromyography (sEMG), the average value, and variation of the relaxation ratios (RR).

METHODS

Five databases were searched (PubMed, EMBASE, Web of Sciences, Cochrane Library, Pedro). A qualitative analysis was done for all included studies and meta-analysis studying prevalence, mean value of flexion relaxation ratio (FRR) and extension relaxation ratio (ERR), and difference between asymptomatic and NSCLBP FRR.

RESULTS

Twenty-seven studies were included for qualitative analysis and 21 studies for meta-analysis. The prevalence of the altered FRP was 55% (95%CI [32-79%]) in the NSCLBP population. The studies on reliability reported good within-session and between-session reproducibility. In the NSLBP population, the mean FRR was 2.96 (95%CI [2.02; 3.90]) and the mean ERR was 4.07 (95%CI [2.08; 6.07]). The difference between asymptomatic and NSCLBP FRR was - 1.19 (95%CI [- 1.92, - 0.45]). In all meta-analysis, the I² index was > 80%.

CONCLUSION

An altered FRP is frequently found in NSCLBP population using sEMG and the test has a good reproducibility. The difference between asymptomatic and NSCLBP FRR was significant. Nevertheless, considering the high heterogeneity observed, additional research is required to confirm the value of RR.

Kinematic analysis of movement impaired by generalization of fear of movement-related pain in workers with low back pain

Purpose

To identify impaired trunk movement during work-related activity in individuals with low back pain (LBP) and investigate whether abnormalities were caused by generalized fear of movement-related pain.

Methods

This cross-sectional study was conducted at a hospital in Japan. We recruited 35 participants with LBP (LBP group; 26 males, 9 females) and 20 healthy controls (HC group) via posters at our hospital. The task required lifting an object. We used a 3D motion capture system to calculate the peak angular velocity of trunk flexion and extension during a lifting task. Pain-related factors for the LBP group were assessed using the visual analogue scale (VAS) for pain intensity over the past 4 weeks and during the task, the Tampa Scale for Kinesiophobia (TSK), the Pain Catastrophizing Scale (PCS), and the Pain Anxiety Symptoms Scale-20 (PASS-20). We compared kinematic variables between groups with a generalized linear mixed model and investigated the relationship between kinematic variables, VAS scores, and psychological factors by performing a mediation analysis.

Results

The peak angular velocity of trunk extension showed significant main effects on the group factors (LBP group vs. HC group) and their interactions; the value of the kinematic variable was lower at Trial 1 in the LBP group. No LBP participant reported pain during the experiment. The mediation analysis revealed that the relationship between the VAS score for pain intensity over the past 4 weeks and the peak angular velocity of trunk extension in the first trial was completely mediated by the TSK (complete mediation model, 95% bootstrapped CI: 0.07–0.56).

Conclusion

Individuals with LBP had reduced trunk extension during a lifting task. Generalized fear of movement-related pain may contribute to such impaired trunk movement. Our findings suggest that intervention to ameliorate fear of movement may be needed to improve LBP-associated disability.

Association between pain and gait instability in patients with lumbar disc herniation

Objective

To determine whether pain is associated with gait instability in patients with lumbar disc herniation (LDH).

Methods

This retrospective cross-sectional study used data from electronic medical records. Among patients with lumbar back pain caused by LDH between January 2017 and July 2019, patients that underwent gait analysis were included. LDH was diagnosed using magnetic resonance imaging. An OptoGait photoelectric cell system was used for gait evaluation. Instability was measured using a gait symmetry index. Multivariate linear regression analysis was performed to determine the association between lumbar pain and gait instability.

Results

A total of 29 patients (12 females [41.4%] and 17 males [58.6%]; mean ± SD age, 40.6 ± 12.0 years) with LDH were enrolled in the study. With each 1-point increase in lumbar pain on the numeric rating scale, the symmetry index of the stance phase (0.33; 95% confidence interval [CI] 0.04, 0.62), swing phase (0.78; 95% CI 0.14, 1.43) and single support (0.79; 95% CI 0.15, 1.43) increased.

Conclusions

Gait instability in patients with LDH may occur due to an increase in pain.

Kinematic changes in goal-directed movements in a fear-conditioning paradigm

In individuals with a musculoskeletal disorder, goal-directed reaching movements of the hand are distorted. Here, we investigated a pain-related fear-conditioning effect on motor control. Twenty healthy participants (11 women and 9 men, 21.7 ± 2.7 years) performed a hand-reaching movement task. In the acquisition phase, a painful electrocutaneous stimulus was applied on the reaching hand simultaneous with the completion of reaching. In the subsequent extinction phase, the task context was the same but the painful stimulus was omitted. We divided the kinematic data of the hand-reaching movements into acceleration and deceleration periods based on the movement-velocity characteristics, and the duration of each period indicated the degree of impairment in the feedforward and feedback motor controls. We assessed the wavelet coherence between electromyograms of the triceps and biceps brachii muscles. In the acquisition phase, the durations of painful movements were significantly longer in both the acceleration and deceleration periods. In the extinction phase, painful movements were longer only in the acceleration period and higher pain expectation and fear were maintained. Similarly, the wavelet coherence of muscles in both periods were decreased in both the acquisition and extinction phases. These results indicate that negative emotional modulations might explain the altered motor functions observed in pain patients.

Relationship between psychological factors and spinal motor behaviour in low back pain: a systematic review and meta-analysis

ABSTRACT

This meta-analysis investigated whether more negative psychological factors are associated with less spinal amplitude of movement and higher trunk muscle activity in individuals with low back pain. Furthermore, it examined whether pain intensity was a confounding factor in this relationship. We included studies that provided at least 1 correlation coefficient between psychological (pain-related fear, catastrophizing, depression, anxiety, and self-efficacy) and spinal motor behaviour (spinal amplitude and trunk muscle activity) measures. In total, 52 studies (3949 participants) were included. The pooled correlation coefficients (95% confidence interval; number of participants) were -0.13 (-0.18 to -0.09; 2832) for pain-related fear, -0.16 (-0.23 to -0.09; 756) for catastrophizing, -0.08 (-0.13 to -0.03; 1570) for depression, -0.08 (-0.30 to 0.14; 336) for anxiety, and -0.06 (-0.46 to 0.36; 66) for self-efficacy. The results indicated that higher levels of pain-related fear, catastrophizing, and depression are significantly associated with reduced amplitudes of movement and larger muscle activity and were consistent across subgroup and moderation analyses. Pain intensity did not significantly affect the association between these psychological factors and spinal motor behaviour and had a very small independent association with spinal motor behaviour. In conclusion, the very small effect sizes found in the meta-analyses question the role of psychological factors as major causes of spinal movement avoidance in low back pain. Experimental studies with more specific and individualized measures of psychological factors, pain intensity, and spinal motor behaviour are recommended.

Changes in Lumbo-Pelvic Coordination of Individuals With and Without Low Back Pain When Wearing a Hip Orthosis

Individuals with low back pain demonstrate an abnormal lumbo-pelvic coordination compared to back-healthy individuals. This abnormal coordination presents itself as a reduction in lumbar contributions and an increase in pelvic rotations during a trunk forward bending and backward return task. This study investigated the ability of a hip orthosis in correcting such an abnormal lumbo-pelvic coordination by restricting pelvic rotation and, hence increasing lumbar contributions. The effects of the hip orthosis on the lumbo-pelvic coordination were investigated in 20 low back pain patients and 20 asymptomatic controls. The orthosis reduced pelvic rotation by 12.7° and increased lumbar contributions by 11%. Contrary to our expectation, orthosis-induced changes in lumbo-pelvic coordination were smaller in patients; most likely because our relatively young patient group had smaller unrestricted pelvic rotations compared to asymptomatic individuals. Considering the observed capability of a hip orthosis in causing the expected changes in lumbo-pelvic coordination when there is a relatively large pelvic contribution to trunk motion, application of a hip orthosis may provide a promising method of correcting abnormal lumbo-pelvic coordination, particularly among patients who demonstrate larger pelvic rotation, that warrants further investigation.

Cortical dynamics of movement-evoked pain in chronic low back pain

KEY POINTS

Cortical activity underlying movement-evoked pain is not well understood, despite being a key symptom of chronic musculoskeletal pain. We combined high-density electroencephalography with a full-body reaching protocol in a virtual reality environment to assess cortical activity during movement-evoked pain in chronic low back pain. Movement-evoked pain in individuals with chronic low back pain was associated with longer reaction times, delayed peak velocity and greater movement variability. Movement-evoked pain was associated with attenuated disinhibition in prefrontal motor areas, as evidenced by an attenuated reduction in beta power in the premotor cortex and supplementary motor area.

ABSTRACT

Although experimental pain alters neural activity in the cortex, evidence of changes in neural activity in individuals with chronic low back pain (cLBP) remains scarce and results are inconsistent. One of the challenges in studying cLBP is that the clinical pain fluctuates over time and often changes during movement. The goal of the present study was to address this challenge by recording high-density electroencephalography (HD-EEG) data during a full-body reaching task to understand neural activity during movement-evoked pain. HD-EEG data were analysed using independent component analyses, source localization and measure projection analyses to compare neural oscillations between individuals with cLBP who experienced movement-evoked pain and pain-free controls. We report two novel findings. First, movement-evoked pain in individuals with cLBP was associated with longer reaction times, delayed peak velocity and greater movement variability. Second, movement-evoked pain was associated with an attenuated reduction in beta power in the premotor cortex and supplementary motor area. Our observations move the field forward by revealing attenuated disinhibition in prefrontal motor areas during movement-evoked pain in cLBP.

The relationship between indicators of lumbo-pelvic coordination and pain, disability, pain catastrophizing and depression in patients presenting with non-chronic low back pain

This study examined associations and changes overtime in low back kinematics and disability, pain, pain catastrophizing, and depression and assessed whether associations and changes overtime varied between individuals who meet the classification criteria for chronic low back pain at 6 months and those who do not. Findings suggested that those persons with a higher ratio of lumbar contribution to thorax motion and smaller pelvic tilt during forward bending had higher scores on measures of disability, pain and pain catastrophizing. This same association was found in those who met classification criteria for chronic low back pain at 6 months. Opposing associations were found in the group not meeting classification criteria for chronic low back pain, specifically, increased pelvic tilt was positively associated with higher pain catastrophizing scores. Practitioner summary This study examined associations and changes overtime in low back kinematics and psychosocial and clinical factors and whether associations and changes overtime varied between individuals who meet the classification criteria for chronic low back pain at 6 months and those who do not, Results suggest that associations exist between psychological factors and kinematic changes during the time between an acute low back pain episode to meeting classification for chronic low back pain at 6 months.

Avoidance Behavioral Difference in Acquisition and Extinction of Pain-Related Fear

Fear of movement-related pain leads to two types of avoidance behavior: excessive avoidance and pain-inhibited movement. Excessive avoidance is an absence of movement by fear, and pain-inhibited movements involve a change in motor behavior for the purpose of protecting the painful part. Here, we sought to clarify the acquisition process and adaptation of fear for each avoidance behavior. Thirty-one female and 13 male (age 20.9 ± 2.1 years) subjects could decide persistent behaviors: approach with an intense pain stimulus, pain-inhibited movement with weak pain stimulus, or excessive avoidance with no pain in acquisition and test phases. In the subsequent extinction phase, the pain stimulus was omitted. Subjects were divided into an approach group (n = 24), a pain-inhibited movement group (n = 10), and an excessive avoidance group (n = 10) by cluster analysis. The response latencies in approach and pain-inhibited movement groups were not affected by conditioned pain. The subjects in the excessive avoidance group exhibited delayed response latencies, and their high-fear responses remained in the acquisition, test, and extinction phases. In addition, the excessive avoidance group showed high harm avoidance and high trait anxiety. This study demonstrated that differences in pain-related avoidance behaviors are affected by psychological traits. Pain-related excessive avoidance behavior indicated a maladaptive fear, but pain-inhibited movement did not.

The relationship between guarding, pain, and emotion

INTRODUCTION

Pain-related behavior in people with chronic pain is often overlooked in a focus on increasing the amount of activity, yet it may limit activity and maintain pain and disability. Targeting it in treatment requires better understanding of the role of beliefs, emotion, and pain in pain behavior.

OBJECTIVES

This study aimed to clarify the interrelationships between guarding, pain, anxiety, and confidence in movement in people with chronic pain in everyday movements.

METHODS

Physiotherapists rated extent of guarding on videos of people with chronic pain and healthy controls making specific movements. Bayesian modelling was used to determine how guarding was related to self-reported pain intensity, anxiety, and emotional distress, and observer-rated confidence in movement.

RESULTS

The absence of guarding was associated with low levels of pain, anxiety, distress, and higher movement self-efficacy, but guarding behavior occurred at high and low levels of each of those variables. Guarding was not directly dependent on pain but on anxiety; the relationship between pain and guarding was mediated by anxiety, with a high probability. Nor was guarding directly related to the broader distress score, but to self-efficacy for movement, again with a high probability.

CONCLUSION

Pain-related guarding is more likely to be effectively addressed by intervention to reduce anxiety rather than pain (such as analgesia); more attention to how people move with chronic pain, rather than only how much they move, is likely to help to extend activity.

Cognitive functional therapy (CFT)-based rehabilitation improves clinical outcomes in UK military personnel with persistent low back pain

Introduction

Low back pain (LBP) has been reported as the most common reason for presentation to the Medical Centre in the British Military, and the most common re-referral for the same condition. In 2015, the UK Defence Medical Rehabilitation Centre (DMRC) adopted a cognitive functional therapy (CFT) approach to spinal rehabilitation in line with National Institute for Health and Care Excellence and military best practice guidelines. The aim of this study is to evaluate the functional and psychosocial outcomes of all patients with chronic LBP treated with CFT-based multidisciplinary rehabilitation at DMRC, Headley Court.

Methods

A prospective observational service evaluation of British Military patients (n=238) with LBP who attended 3 weeks of inpatient multidisciplinary CFT-based programme from 2015 to the end of 2017 at DMRC was analysed. Functional outcomes include: multistage locomotion test (MSLT) and sit and reach test. Psychosocial outcomes include: Tampa Scale of Kinesiophobia, Oswestry Disability Index, Brief Pain Inventory (BPI), General Anxiety Disorder-7 and Patient Health Questionnaire-9.

Results

There were significant improvements in endurance (MSLT), range of motion, kinesiophobia, pain-related lifestyle interference (BPI-Lifestyle), anxiety and depression (p≤0.001). However, no improvements in pain intensity (BPI-Intensity) were demonstrated (p>0.05).

Conclusion

After 3 weeks of CFT-based multidisciplinary rehabilitation, function and psychosocial health improved with symptoms of pain being less obtrusive to activities of daily activity. There were however no patient-reported reductions in pain intensity. The improvements demonstrated are indicative of outcomes that facilitate greater integration back to work or into society.

Lumbar range of motion in chronic low back pain is predicted by task-specific, but not by general measures of pain-related fear

BACKGROUND

Most studies fail to show an association between higher levels of pain-related fear and protective movement behaviour in patients with chronic low back pain (CLBP). This may be explained by the fact that only general measures of pain-related fear have been used to examine the association with movement patterns. This study explored whether task-specific, instead of general measures of pain-related fear can predict movement behaviour.

METHODS

Fifty-five patients with CLBP and 54 healthy persons performed a lifting task while kinematic measurements were obtained to assess lumbar range of motion (ROM). Scores on the Photograph Daily Activities Series-Short Electronic Version (PHODA-SeV), Tampa Scale for Kinesiophobia and its Activity Avoidance and Somatic Focus subscales were used as general measures of pain-related fear. The score on a picture of the PHODA-SeV, showing a person lifting a heavy object with a bent back, was used as task-specific measure of pain-related fear.

RESULTS

Lumbar ROM was predicted by task-specific, but not by general measures of pain-related fear. Only the scores on one other picture of the PHODA-SeV, similar to the task-specific picture regarding threat value and movement characteristics, predicted the lumbar ROM. Compared to healthy persons, patients with CLBP used significantly less ROM, except the subgroup with a low score on the task-specific measure of pain-related fear, who used a similar ROM.

CONCLUSIONS

Our results suggest to use task-specific measures of pain-related fear when assessing the relationship with movement. It would be of interest to investigate whether reducing task-specific fear changes protective movement behaviour.

SIGNIFICANCE

This study shows that lumbar range of motion in CLBP is predicted by task-specific, but not by general measures of pain-related fear. This suggests that both in clinical practice and for research purposes, it might be recommended to use task-specific measures of pain-related fear when assessing the relationship with movement behaviour. This may help to disentangle the complex interactions between pain-related fear, movement and disability in patients with CLBP.

A challenge on Orthopedic Sciences: The Influence of Spinal Disease and Deformities on Total Hip Arthroplasty: A Review on Literature

BACKGROUND

Adult degenerative disorders of hip and spine are common. The recent studies inconsistently have discussed about the influence of spinal disorders on total hip arthroplasty (THA). In this review, we discussed clearly about these relationships and their effects on the most appropriate position of the acetabular component.

METHODS

We searched on databases and evaluated the articles about spinopelvic parameters in patients with spinal disorders who needed THA.

RESULTS

The literature search showed a prevalence of 21.2 % to 60.4% of low back pain (LBP) in patients, who are candidates for primary THA. The coexistence of degenerative disease of hip and spine or other diseases can significantly alter spinopelvic alignment. Accordingly, pain management or any other treatment in these patients requires proper understanding about the biomechanics of the hip and the spinal and their corresponding interactions. In this review article, we discussed about these interactions and their effects on the most appropriate position of the acetabular component.

CONCLUSION

We concluded that counseling sessions among patients, orthopedic surgeons and spine surgeons can result in obtaining the best outcome for these individuals.

Virtual immersive gaming to optimize recovery (VIGOR) in low back pain: A phase II randomized controlled trial

The virtual immersive gaming to optimize recovery (VIGOR) study is a randomized controlled trial of the effects of virtual reality games to encourage lumbar spine flexion among individuals with chronic low back pain and fear of movement. Whereas traditional graded activity or graded exposure therapies for chronic low back pain have high attrition and poor long-term efficacy, we believe that virtual reality games have distinct advantages that can enhance adherence and clinical outcomes. First, they are engaging and enjoyable activities that can distract from pain and fear of harm. In addition, because they gradually reinforce increases in lumbar spine flexion to achieve game objectives, continued engagement over time is expected to promote recovery through restoration of normal spinal motion. The study design includes two treatment groups which differ in the amount of lumbar flexion required to achieve the game objectives. All participants will play the games for nine weeks, and pre-treatment to 1-week post-treatment changes in pain and disability will serve as the co-primary clinical outcomes. In addition, changes in lumbar flexion and expectations of pain/harm will be examined as potential treatment outcome mediators. Maintenance of treatment outcomes will also be assessed for up to 48-weeks post-treatment. In brief, we hypothesize that the virtual reality games will reduce pain and disability by promoting spinal motion and allowing participants to develop an implicit understanding that they are capable of engaging in significant lumbar spine motion in their daily lives without a risk of injury to their back.

A randomized control trial to determine the effectiveness and physiological effects of spinal manipulation and spinal mobilization compared to each other and a sham condition in patients with chronic low back pain: Study protocol for The RELIEF Study

BACKGROUND

Low back pain (LBP) is one of the most common reasons for seeking medical care. Manipulative therapies are a common treatment for LBP. Few studies have compared the effectiveness of different types of manipulative therapies. Moreover, the physiologic mechanisms underlying these treatments are not fully understood. Herein, we present the study protocol for The Researching the Effectiveness of Lumbar Interventions for Enhancing Function Study (The RELIEF Study).

METHODS AND STUDY DESIGN

The RELIEF Study is a Phase II RCT with a nested mechanistic design. It is a single-blinded, sham-controlled study to test the mechanisms and effectiveness of two manual therapy techniques applied to individuals (n = 162; 18-45 years of age) with chronic LBP. The clinical outcome data from the mechanistic component will be pooled across experiments to permit an exploratory Phase II RCT investigating the effectiveness. Participants will be randomized into one of three separate experiments that constitute the mechanistic component to determine the muscular, spinal, and cortical effects of manual therapies. Within each of these experimental groups study participants will be randomly assigned to one of the three treatment arms: 1) spinal manipulation, 2) spinal mobilization, or 3) sham laser therapy. Treatments will be delivered twice per week for 3-weeks.

DISCUSSION

This data from this will shed light on the mechanisms underlying popular treatments for LBP. Additionally, the coupling of this basic science work in the context of a clinical trial will also permit examination of the clinical efficacy of two different types of manipulative therapies.

Attention demands of postural control in non-specific chronic low back pain subjects with low and high pain-related anxiety

Impaired postural control in chronic low back pain (CLBP) has been attributed to deficits in sensory and motor functions. However, it is not known if pain-related anxiety affects motor and cognitive function of postural control. The aim of this study was to compare the interactive effects of postural and cognitive function in CLBP patients with high and low pain-related anxiety and healthy subjects. Thirty-eight patients with nonspecific CLBP (19 with low and 19 with high pain-related anxiety levels) and 20 asymptomatic subjects participated. Postural control was assessed by center of pressure (COP) parameters including mean total sway velocity, area, anterior-posterior (A-P), and medial-lateral (Med-Lat) range. Postural task was assessed during four conditions (eyes open with and without ankle vibration-eyes closed with and without ankle vibrations). Participants performed the postural task with or without auditory Stroop task. Average reaction time and error ratio of auditory Stroop test were calculated as measures of the cognitive task performance. Significantly reduced sway area was observed in CLBP patients with high pain-related anxiety and control subjects during the dual-task condition as compared with the single task. In addition, A-P range was significantly reduced in CLBP patients with high pain-related anxiety during dual tasking when eyes were closed with ankle vibration. In addition, only the CLBP subjects with high pain-related anxiety showed significantly longer reaction times by increasing the difficulty of standing postural task. Pain-related anxiety may influence the postural cognitive interactions in CLBP patients. Furthermore, it may be considered as a contributing factor for postural strategies adopted by CLBP patients.

Influences of lumbar disc herniation on the kinematics in multi-segmental spine, pelvis, and lower extremities during five activities of daily living

Background

Low back pain (LBP) is a common problem that can contribute to motor dysfunction. Previous studies reporting the changes in kinematic characteristics caused by LBP present conflicting results. This study aimed to apply the multisegmental spinal model to investigate the kinematic changes in patients with lumbar disc herniation (LDH) during five activities of daily living (ADLs).

Methods

Twenty-six healthy subjects and 7 LDH patients participated in this study and performed level walking, stair climbing, trunk flexion, and ipsilateral and contralateral pickups. The angular displacement of the thorax, upper lumbar (ULx), lower lumbar (LLx), pelvis, hip, and knee was calculated using a modified full-gait-model in the AnyBody modeling system.

Results

In the patient group, the ULx almost showed no sagittal angular displacement while the LLx remained part of the sagittal angular displacement during trunk flexion and the two pickups. In the two pickups, pelvic tilt and lower extremities’ flexion increased to compensate for the deficiency in lumbar motion. LDH patients exhibited significantly less pelvic rotation during stair climbing and greater pelvic rotation in other ADLs, except in contralateral pickup. In addition, LDH patients demonstrated more antiphase movement in the transverse plane between ULx and LLx, during level walking and stair climbing, between thorax and pelvis in the two pickups.

Conclusions

LDH patients mainly restrict the motion of LLx and ULx in the spinal region during the five ADLs. Pelvic rotation is an important method to compensate for the limited lumbar motion. Furthermore, pelvic tilt and lower extremities’ flexion increased when ADLs were quite difficult for LDH patients.

The Impact of Lumbar Spine Disease and Deformity on Total Hip Arthroplasty Outcomes

Concomitant spine and hip disease in patients undergoing total hip arthroplasty (THA) presents a management challenge. Degenerative lumbar spine conditions are known to decrease lumbar lordosis and limit lumbar flexion and extension, leading to altered pelvic mechanics and increased demand for hip motion. In this study, the effect of lumbar spine disease on complications after primary THA was assessed. The Medicare database was searched from 2005 to 2012 using International Classification of Diseases, Ninth Revision, procedure codes for primary THA and diagnosis codes for preoperative diagnoses of lumbosacral spondylosis, lumbar disk herniation, acquired spondylolisthesis, and degenerative disk disease. The control group consisted of all patients without a lumbar spine diagnosis who underwent THA. The risk ratios for prosthetic hip dislocation, revision THA, periprosthetic fracture, and infection were significantly higher for all 4 lumbar diseases at all time points relative to controls. The average complication risk ratios at 90 days were 1.59 for lumbosacral spondylosis, 1.62 for disk herniation, 1.65 for spondylolisthesis, and 1.53 for degenerative disk disease. The average complication risk ratios at 2 years were 1.66 for lumbosacral spondylosis, 1.73 for disk herniation, 1.65 for spondylolisthesis, and 1.59 for degenerative disk disease. Prosthetic hip dislocation was the most common complication at 2 years in all 4 spinal disease cohorts, with risk ratios ranging from 1.76 to 2.00. This study shows a significant increase in the risk of complications following THA in patients with lumbar spine disease. [Orthopedics. 2017; 40(3):e520-e525.].

Trunk kinematics and low back pain during pruning among vineyard workers-A field study at the Chateau Larose-Trintaudon

The prevalence of low back disorders is dramatically high in viticulture. Field measurements that objectively quantify work exposure can provide information on the relationship between the adopted trunk postures and low back pain. The purposes of the present study were three-fold (1) to carry out a kinematics analysis of vineyard-workers’ pruning activity by extracting the duration of bending and rotation of the trunk, (2) to question separately the relationship between the duration of forward bending or trunk rotation with low back pain intensity and pressure pain sensitivity and (3) to question the relationship between the combined duration of forward bending and trunk rotation on low back pain intensity and pressure pain sensitivity. Fifteen vineyard-workers were asked to perform pruning activity for 12 minutes with a wireless triaxial accelerometer placed on their trunk. Kinematic analysis of the trunk showed that vineyard-workers spent more than 50% of the time with the trunk flexed greater than 30° and more than 20% with the trunk rotated greater than 10°. These results show that pruning activity lead to the adoption of forward bended and rotated trunk postures that could significantly increase the risk of work related musculoskeletal disorders in the low back. However, this result was mitigated by the observation of an absence of significant association between the duration of forward bending and trunk rotation with low back pain intensity or pressure pain sensitivity. Even if prospective field measurements and studies assessing the effects of low back pain confounders are needed, this field study provides new genuine information on trunk kinematics during pruning activity.

Association of Quadriceps Strength and Psychosocial Factors With Single-Leg Hop Performance in Patients With Meniscectomy

Background:

Clinicians use the single-leg hop test to assess readiness for return to sports after knee injury. Few studies have reported the results of single-leg hop testing after meniscectomy. Additionally, the contributions of impairments in quadriceps strength and psychosocial factors to single-leg hop performance are unknown.

Purpose:

To compare single-leg hop performance (distance and landing mechanics) between limbs and to examine the association of single-leg hop performance with quadriceps strength and psychosocial factors in patients with meniscectomy.

Study Design:

Descriptive laboratory study.

Methods:

A total of 22 subjects who underwent meniscectomy for traumatic meniscal tears received either standard rehabilitation alone or with additional quadriceps strengthening. Testing was conducted immediately postrehabilitation and at 1 year postsurgery. A single-leg hop test was performed bilaterally, and hop distance was used to create a hop symmetry index. Landing mechanics (peak knee flexion angle, knee extension moment, and peak vertical ground-reaction force) were analyzed with a motion-capture system and a force plate. An isokinetic dynamometer (60 deg/s) assessed knee extensor peak torque and rate of torque development (RTD_0-200ms and RTD_{0–peak torque}). Questionnaires assessed fear of reinjury (Tampa Scale for Kinesiophobia [TSK-11]) and self-efficacy (Knee Activity Self-Efficacy [KASE]).

Results:

Rehabilitation groups did not significantly differ in single-leg hop performance; therefore, groups were combined for further analyses. The mean hop symmetry index was 88.6% and 98.9% at postrehabilitation and 1 year postsurgery, respectively. Compared with the nonsurgical limb, the surgical limb showed decreased peak knee flexion angle at postrehabilitation and decreased knee extension moment at 1 year postsurgery. The hop symmetry index was positively associated with peak torque, RTD_0-200ms, and the KASE score at postrehabilitation. Moreover, at postrehabilitation, the peak knee flexion angle was positively associated with peak torque and RTD_0-200ms, and the knee extension moment was positively associated with RTD_0-200ms. At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD_0-200ms, and RTD_{0–peak torque}.

Conclusion:

Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation.

Clinical Relevance:

Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance.

Feasibility and Safety of a Virtual Reality Dodgeball Intervention for Chronic Low Back Pain: A Randomized Clinical Trial

Whereas the fear-avoidance model of chronic low back pain (CLBP) posits a generic avoidance of movement that is perceived as threatening, we have repeatedly shown that individuals with high fear and CLBP specifically avoid flexion of the lumbar spine. Accordingly, we developed a virtual dodgeball intervention designed to elicit graded increases in lumbar spine flexion while reducing expectations of fear and harm by engaging participants in a competitive game that is entertaining and distracting. We recruited 52 participants (48% female) with CLBP and high fear of movement and randomized them to either a game group (n = 26) or a control group (n = 26). All participants completed a pregame baseline and a follow-up assessment (4-6 days later) of lumbar spine motion and expectations of pain and harm during standardized reaches to high (easier), middle, and low (hardest to reach) targets. For 3 consecutive days, participants in the game group completed 15 minutes of virtual dodgeball between baseline and follow-up. For the standardized reaching tests, there were no significant effects of group on changes in lumbar spine flexion, expected pain, or expected harm. However, virtual dodgeball was effective at increasing lumbar flexion within and across gameplay sessions. Participants reported strong positive endorsement of the game, no increases in medication use, pain, or disability, and no adverse events. Although these findings indicate that very brief exposure to this game did not translate to significant changes outside the game environment, this was not surprising because graded exposure therapy for fear of movement among individuals with low back pain typically last 8 to 12 sessions. Because of the demonstration of safety, feasibility, and ability to encourage lumbar flexion within gameplay, these findings provide support for a clinical trial wherein the treatment dose is more consistent with traditional graded exposure approaches to CLBP.

PERSPECTIVE

This study of a virtual reality dodgeball intervention provides evidence of feasibility, safety, and utility to encourage lumbar spine flexion among individuals with CLBP and high fear of movement.

Effects of Real-World Versus Virtual Environments on Joint Excursions in Full-Body Reaching Tasks

Starting from an upright standing posture and reaching for a target that requires some forward bending of the trunk can involve many different configurations of the trunk and limb segments. We sought to determine if configurations of the limb and trunk segments during our standardized full-body reaching tasks were influenced by the visual environment. This paper examined movement patterns of healthy participants (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$n=17$ \end{document}, eight female and nine male) performing full body reaching tasks to: 1) real-world targets; 2) virtual targets presented on a 3-D television; and 3) virtual targets presented using a head-mounted display. For reaches performed in the virtual world, the avatar was presented from a third-person perspective for the 3-D television and from a first-person perspective for the head-mounted display. Reaches to virtual targets resulted in significantly greater excursions of the ankle, knee, hip, spine, and shoulder compared with reaches made to real-world targets. This resulted in significant differences in the forward and downward displacements of the whole-body center of mass between the visual environments. Visual environment clearly influences how subjects perform full-body reaching tasks to static targets. Because a primary goal of virtual reality within rehabilitation is often to restore movement following orthopedic or neurologic injury, it is important to understand how visual environment will affect motor behavior. The present findings suggest that the existing game systems that track and present avatars from a third-person perspective elicit significantly different motor behavior when compared with the same tasks being presented from a first-person perspective.

The Automatic Detection of Chronic Pain-Related Expression: Requirements, Challenges and the Multimodal EmoPain Dataset

Pain-related emotions are a major barrier to effective self rehabilitation in chronic pain. Automated coaching systems capable of detecting these emotions are a potential solution. This paper lays the foundation for the development of such systems by making three contributions. First, through literature reviews, an overview of how pain is expressed in chronic pain and the motivation for detecting it in physical rehabilitation is provided. Second, a fully labelled multimodal dataset (named 'EmoPain') containing high resolution multiple-view face videos, head mounted and room audio signals, full body 3D motion capture and electromyographic signals from back muscles is supplied. Natural unconstrained pain related facial expressions and body movement behaviours were elicited from people with chronic pain carrying out physical exercises. Both instructed and non-instructed exercises were considered to reflect traditional scenarios of physiotherapist directed therapy and home-based self-directed therapy. Two sets of labels were assigned: level of pain from facial expressions annotated by eight raters and the occurrence of six pain-related body behaviours segmented by four experts. Third, through exploratory experiments grounded in the data, the factors and challenges in the automated recognition of such expressions and behaviour are described, the paper concludes by discussing potential avenues in the context of these findings also highlighting differences for the two exercise scenarios addressed.

Effects of Visual Display on Joint Excursions Used to Play Virtual Dodgeball

Background

Virtual reality (VR) interventions hold great potential for rehabilitation as commercial systems are becoming more affordable and can be easily applied to both clinical and home settings.

Objective

In this study, we sought to determine how differences in the VR display type can influence motor behavior, cognitive load, and participant engagement.

Methods

Movement patterns of 17 healthy young adults (8 female, 9 male) were examined during games of Virtual Dodgeball presented on a three-dimensional television (3DTV) and a head-mounted display (HMD). The participant’s avatar was presented from a third-person perspective on a 3DTV and from a first-person perspective on an HMD.

Results

Examination of motor behavior revealed significantly greater excursions of the knee (P=.003), hip (P<.001), spine (P<.001), shoulder (P=.001), and elbow (P=.026) during HMD versus 3DTV gameplay, resulting in significant differences in forward (P=.003) and downward (P<.001) displacement of the whole-body center of mass. Analyses of cognitive load and engagement revealed that relative to 3DTV, participants indicated that HMD gameplay resulted in greater satisfaction with overall performance and was less frustrating (P<.001). There were no significant differences noted for mental demand.

Conclusions

Differences in visual display type and participant perspective influence how participants perform in Virtual Dodgeball. Because VR use within rehabilitation settings is often designed to help restore movement following orthopedic or neurologic injury, these findings provide an important caveat regarding the need to consider the potential influence of presentation format and perspective on motor behavior.

Does Degenerative Lumbar Spine Disease Influence Femoroacetabular Flexion in Patients Undergoing Total Hip Arthroplasty?

BACKGROUND

Sitting pelvic tilt dictates the proximity of the rim of the acetabulum to the proximal femur and, therefore, the risk of impingement in patients undergoing total hip arthroplasty (THA). Sitting position is achieved through a combination of lumbar spine segmental motions and/or femoroacetabular articular motion in the lumbar-pelvic-femoral complex. Multilevel degenerative disc disease (DDD) may limit spine flexion and therefore increase femoroacetabular flexion in patients having THAs, but this has not been well characterized. Therefore, we measured standing and sitting lumbar-pelvic-femoral alignment in patients with radiographic signs of DDD and in patients with no radiographic signs of spine arthrosis.

QUESTIONS/PURPOSES

We asked: (1) Is there a difference in standing and sitting lumbar-pelvic-femoral alignment before surgery among patients undergoing THA who have no radiographic signs of spine arthrosis compared with those with preexisting lumbar DDD? (2) Do patients with lumbar DDD experience less spine flexion moving from a standing to a sitting position and therefore compensate with more femoroacetabular flexion compared with patients who have no radiographic signs of arthrosis?

METHODS

Three hundred twenty-five patients undergoing primary THA had preoperative low-dose EOS spine-to-ankle lateral radiographs in standing and sitting positions. Eighty-three patients were excluded from this study for scoliosis (39 patients), spondylolysis (15 patients), not having five lumbar vertebrae (7 patients), surgical or disease fusion (11 patients), or poor image quality attributable to high BMI (11 patients). In the remaining 242 of 325 patients (75%), two observers categorized the lumbar spine as either without radiographic arthrosis or having DDD based on defined radiographic criteria. Sacral slope, lumbar lordosis, and proximal femur angles were measured, and these angles were used to calculate lumbar spine flexion and femoroacetabular flexion in standing and sitting positions. Patients were aligned in a standardized sitting position so that their femurs were parallel to the floor to achieve approximately 90° of apparent hip flexion.

RESULTS

After controlling for age, sex, and BMI, we found patients with DDD spines had a mean of 5° more posterior pelvic tilt (95% CI, -2° to -8° lower sacral slope angles; p < 0.01) and 7° less lumbar lordosis (95% CI, -10° to -3°; p < 0.01) in the standing position compared with patients without radiographic arthrosis. However, in the sitting position, patients with DDD spines had 4° less posterior pelvic tilt (95% CI, 1°-7° higher sacral slope angles; p = 0.02). From standing to sitting position, patients with DDD spines experienced 10° less spine flexion (95% CI, -14° to -7°; p < 0.01) and 10° more femoroacetabular flexion (95% CI, 6° to 14°; p < 0.01).

CONCLUSIONS

Most patients undergoing THA sit in a similar range of pelvic tilt, with a small mean difference in pelvic tilt between patients with DDD spines and those without radiographic arthrosis. However, in general, the mechanism by which patients with DDD of the lumbar spine achieve sitting differs from those without spine arthrosis with less spine flexion and more femoroacetabular flexion.

CLINICAL RELEVANCE

When planning THA, it may be important to consider which patients sit with less posterior pelvic tilt and those who rotate their pelvises forward to achieve a sitting position, as both mechanisms will limit or reduce the functional anteversion of the acetabular component in a patient with a THA. Our study provides some additional perspective on normal relationships between pelvic tilt and femoroacetabular flexion, but further research might better characterize this relationship in outliers and the possible implications for posterior instability after THA.

The Impact of Lumbar Spine Disease and Deformity on Total Hip Arthroplasty Outcomes

Concurrent spine and hip disease is common. Spinal deformities can restrict lumbar range of motion and lumbar lordosis, leading to pelvic obliquity and increased pelvic tilt. A comprehensive preoperative workup and component templating ensure appropriate compensation for altered pelvic parameters for implantation of components according to functional positioning. Pelvic obliquity from scoliosis must be measured to calculate appropriate leg length. Cup positioning should be templated on standing radiograph to limit impingement from cup malposition. In spinal deformity, the optimal position of the cup that accommodates pelvic parameters and limits impingement may lie outside the classic parameters of the safe zone.

The promise and challenge of virtual gaming technologies for chronic pain: the case of graded exposure for low back pain

SUMMARY 

Virtual reality (VR) technologies have been successfully applied to acute pain interventions and recent reviews have suggested their potential utility in chronic pain. The current review highlights the specific relevance of VR interactive gaming technologies for pain-specific intervention, including their current use across a variety of physical conditions. Using the example of graded-exposure treatment for pain-related fear and disability in chronic low back pain, we discuss ways that VR gaming can be harnessed to optimize existing chronic pain therapies and examine the potential limitations of traditional VR interfaces in the context of chronic pain. We conclude by discussing directions for future research on VR-mediated applications in chronic pain.

Are forward bending of the trunk and low back pain associated among Danish blue-collar workers? A cross-sectional field study based on objective measures

The aim of this cross-sectional study was to investigate the association between the duration of objectively measured forward bending of the trunk and low back pain (LBP) intensity among 198 Danish blue-collar workers (male = 115; female = 83). The duration of forward bending of ≥ 30°, ≥ 60° and ≥ 90° was divided into high (the highest tertile) and low-moderate (the remaining tertiles) categories. High (>5) and low ( ≤ 5) pain intensities were categorised from a self-reported 0-9 scale. Results of multi-adjusted logistic regressions indicated no significant positive associations between forward bending and LBP intensity. On the contrary, higher duration of forward bending of ≥ 30° was associated with lower LBP intensity during all day (OR = 0.40; 95% CI, 0.15-1.02; p = 0.05) and work (OR = 0.44; 95% CI, 0.17-1.15; p = 0.09). This indication of a negative association may be explained by fear-avoidance behaviour of the blue-collar worker, job crafting or healthy worker effect.

Performance based on sEMG activity is related to psychosocial components: differences between back and abdominal endurance tests

The influence of psychosocial components on back and abdominal endurance tests in patients with persistent non-specific low back pain should be investigated to ensure the correct interpretation of these measures. Three-hundred and thirty-two patients (291 men and 41 women) from 19 to 63years performed an abdominal and back muscle endurance test after completing some psychosocial questionnaires. During the endurance tests, surface electromyography signals of the internal obliques, the external obliques, the lumbar multifidus and the iliocostalis were recorded. Patients were dichotomized as underperformers and good performers, by comparing their real endurance time, to the expected time of endurance derived from the normalized median frequency slope. Independent t-tests were performed to examine the differences on the outcome of the questionnaires. In the back muscle endurance test, the underperformers had significantly lower (p<0.05) scores on some of the physical subscales of the SF-36. The underperformers group of the AE test scored significantly higher on the DRAM MZDI (p=0.018) and on the PCS scale (p=0.020) and showed also significantly lower scores on the SF-36 (p<0.05). Back muscle endurance tests are influenced by physical components, while abdominal endurance tests seem influenced by psychosocial components.

Neuroimaging Evidence of Motor Control and Pain Processing in the Human Midcingulate Cortex

Human neuroimaging and virus-tracing studies in monkey predict that motor control and pain processes should overlap in anterior midcingulate cortex (aMCC), but there is currently no direct evidence that this is the case. We used a novel functional magnetic resonance imaging paradigm to examine brain activity while subjects performed a motor control task, experienced a pain-eliciting stimulus on their hand, and performed the motor control task while also experiencing the pain-eliciting stimulus. Our experiment produced 3 novel results. First, group-level analyses showed that when separate trials of motor control and pain processing were performed, overlapping functional activity was found in the same regions of aMCC, supplementary motor area (SMA), anterior insula, and putamen. Secondly, increased activity was found in the aMCC and SMA when motor control and pain processing occurred simultaneously. Thirdly, individual-level analyses showed that 93% of subjects engaged the same region of aMCC during separate trials of motor control and pain processing irrespective of differences in the sulcal/gyral morphology of the cingulate cortex across individuals. These observations provide direct evidence in humans that the same region of aMCC is engaged for motor control and pain processing.

Assessment of patient's pain-related behavior at physical examination may allow diagnosis of recent osteoporotic vertebral fracture

BACKGROUND CONTEXT

Although innumerable studies have analyzed the multiple aspects of osteoporotic vertebral fractures, no study has focused on the clinical features related to spine pain in patients with recent osteoporotic vertebral compression fractures (VCFs).

PURPOSE

To determine whether the assessment of pain-related behavior (P-RB) of patients with osteoporotic VCFs of recent onset may allow the fracture to be strongly suspected, or even diagnosed, at physical examination.

STUDY DESIGN

Pain-related behavior of elderly patients attending an outpatient spine clinic was evaluated on the basis of six consecutive movements made on the examining table.

PATIENT SAMPLE

Fifty-six patients complaining only of lumbar or thoracic pain. The fractured patients (FPs), representing the fracture group (FG), were the 19 who had a recent VCF, whereas the control group (CG) consisted of the remaining 37 patients.

METHODS

Assessment of P-RB was based on six parameters: grimacing, sighing, clenching or blocking eyelids, gaping or strongly tightening the lips, need for help to take positions, and extreme difficulty to turn in the prone position. A score of 1 or a decimal was assigned to each parameter, the final score to each patient being 0 to 6. Three types of injury, acute (I), subacute (II), or chronic (III), were identified on the basis of the time elapsed from the probable occurrence of the fracture. The diagnosis of recent fracture was based on magnetic resonance images. Patients were videotaped during their movements. An examiner, unaware of the clinical history and diagnosis, gave a P-RB score to all patients and indicated whether they had to be placed in FG or CG, and also their presumable type of fracture. Subsequently, a DVD with the videotapes of all patients was given to three independent examiners, not specifically expert of spine conditions, who were asked to make the same evaluations as the first examiner.

RESULTS

The mean scores for P-RB given by the first examiner were 4.6 to FG and 0.7 to CG (p<.01). He identified as FPs 89% of those who were in FG. The type of fracture was indicated correctly in 88% of patients identified as FPs. The mean scores for the three types of fracture ranged from 5.4 (Type I) to 3.3 (Type III) (p<.001). The mean scores for P-RB given by the independent examiners to FG and CG were similar to those of the first examiner. The rates of correctness in identifying the type of fracture in patients indicated as FPs varied from 87% to 80%. The mean scores assigned to the patients included in the three types of fracture ranged from 5.4 to 2.8.

CONCLUSIONS

Pain-related behavior evaluation of patients with osteoporotic VCF during their movements on the examining table may allow to suspect, or even diagnose, the presence of a fracture, particularly in the initial 4 to 6 weeks after the occurrence. Even orthopedic surgeons not particularly familiar with spine care may be able to suspect the injury during physical examination.

Relationship between different measures of pain-related fear and physical capacity of the spine in patients with chronic low back pain

BACKGROUND CONTEXT

It has been controversially stated that pain-related fear is a more important determining factor for disability in chronic low back pain (CLBP) than pain or physical impairment in itself. So far, the relationship between psychological and physiological determinants of chronic pain, that is, pain-related fear and physiological abilities, remains unclear.

PURPOSE

To evaluate whether pain-related fear assessed by different tools (both task specific and non task specific) is related to physical capacity measured by specific spine tests and, secondarily, to explore the relationship between different pain-related fear assessment tools.

STUDY DESIGN/SETTING

Cross-sectional study.

PATIENT SAMPLE

Fifty patients with CLBP (50% women; meanage [standard deviationage]: 44.2 [9.5 years]).

OUTCOME MEASURES

Physical capacity by means of three specific spine tests, that is, the finger-floor distance test (flexibility), a maximal isometric strength test of trunk extensor muscles (strength), and the Sorensen test (endurance). Pain-related fear by means of self-report measures, that is, the Tampa Scale for Kinesiophobia (TSK), the Photograph Series of Daily Activities (PHODA), and a fear visual analog scale (FVAS) tailored to the spine tests.

METHODS

Participants were asked to complete the TSK and PHODA and to perform the three spine tests. Right before performing each of the spine tests, an FVAS was filled out. Linear regression analyses controlling for gender and age were performed to study the association between the pain-related fear measurements and the results of the spine tests. To investigate the relationship between the pain-related fear measurements, correlation tests were performed.

RESULTS

The linear regression analyses revealed that neither the TSK and PHODA scores nor the FVAS scores were significantly related to the physical capacity measurements. The correlational tests showed no significant correlation between the PHODA, TSK, and FVAS scores.

CONCLUSIONS

The present study shows that neither the task-specific tool (FVAS) nor the non task-specific questionnaires (TSK and PHODA) were significantly correlated to the spine tests in patients with CLBP. This is contrary to earlier evidence according to which physical capacity is inversely related to the level of pain-related fear, and it suggests that one should not draw conclusions about physical capacity based on pain-related fear scores. Furthermore, the different assessment tools for pain-related fear were surprisingly not correlated with each other.