Cognitive Functional Therapy for People with Nonspecific Persistent Low Back Pain in a Secondary Care Setting-A Propensity Matched, Case-Control Feasibility Study.

BACKGROUND: Effective, inexpensive, and low-risk interventions are needed for patients with nonspecific persistent low back pain (NS-PLBP) who are unresponsive to primary care interventions. Cognitive functional therapy (CFT) is a multidimensional behavioral self-management approach that has demonstrated promising results in primary care and has not been tested in secondary care. OBJECTIVE: To investigate the effect of CFT and compare it with usual care for patients with NS-PLBP. DESIGN: Case-control study. SETTING: A secondary care spine center. SUBJECTS: Thirty-nine patients received a CFT intervention and were matched using propensity scoring to 185 control patients receiving usual care. METHODS: The primary outcome was Roland Morris Disability Questionnaire (0-100 scale) score. Group-level differences at six- and 12-month follow-up were estimated using mixed-effects linear regression. RESULTS: At six-month follow-up, a statistically significant and clinically relevant difference in disability favored the CFT group (-20.7, 95% confidence interval [CI] = -27.2 to -14.2, P < 0.001). Significant differences also occurred for LBP and leg pain, fear, anxiety, and catastrophizing in favor of CFT. At 12-month follow-up, the difference in disability was smaller and no longer statistically significant (-8.1, 95% CI = -17.4 to 1.2, P = 0.086). Differences in leg pain intensity and fear remained significantly in favor of CFT. Treatment satisfaction was significantly higher in the CFT group at six- (93% vs 66%) and 12-month (84% vs 52%) follow-up. CONCLUSIONS: These findings support that CFT is beneficial for patients with NS-PLBP who are unresponsive to primary care interventions. Subsequent randomized controlled trials could incorporate booster sessions, which may result in larger effects at 12-month follow-up.

Correlations between the active straight leg raise, sleep and somatosensory sensitivity during pregnancy with post-partum lumbopelvic pain: an initial exploration.

Background and aims For some women, lumbopelvic pain (LPP) developed during pregnancy becomes a continuing post-partum problem. Increased understanding of potential prognostic factors is required. This study investigated whether active straight leg raise (ASLR), sleep dysfunction and pressure pain sensitivity during pregnancy are correlated with LPP intensity and quality, disability, and physical health-related quality of life (HRQoL) post-partum. Methods An exploratory, prospective cohort study design was used. Baseline factors of interest were: (1) ASLR, (2) Pittsburgh Sleep Quality Index, and (3) pressure pain thresholds (PPTs) collected from pregnant women from sites local and distal to the lumbopelvic area. Follow-up data collected 11-18 months post-partum (n=29) were: (1) pain intensity score (numerical rating scale), (2) pain quality (McGill Pain Questionnaire), (3) disability (Pelvic Girdle Questionnaire), and (4) HRQoL (36-item Short Form Health Survey). Correlation analysis was performed. Results Greater difficulty with an ASLR during pregnancy correlated with lower post-partum physical HRQoL scores (r=-0.563, p=0.002). Likewise, reduced PPTs at the sacrum during pregnancy was correlated with a higher post-partum pain quality score (r=-0.384, p=0.040). Conclusions In this cohort, findings indicate that poor ASLR performance and localised pressure pain hypersensitivity at the pelvis during pregnancy are correlated with post-partum physical HRQoL and pain quality, respectively. Implications Pain sensitivity may contribute to the prognosis of women with LPP during pregnancy. These explorative findings may be important for designing larger prognostic studies and may assist in directing potential pain management in post-partum LPP.

Disrupted Self-Perception in People With Chronic Low Back Pain. Further Evaluation of the Fremantle Back Awareness Questionnaire.

UNLABELLED: Several lines of evidence suggest that body perception is altered in people with chronic back pain. Maladaptive perceptual awareness of the back might contribute to the pain experience as well as serve as a target for treatment. The Fremantle Back Awareness Questionnaire (FreBAQ) is a simple questionnaire recently developed to assess back-specific altered self-perception. The aims of this study were to present the outcomes of a comprehensive evaluation of the questionnaire's psychometric properties and explore the potential relationships between body perception, nociceptive sensitivity, distress, and beliefs about back pain and the contribution these factors might play in explaining pain and disability. Two hundred fifty-one people with chronic back pain completed the questionnaire as well as a battery of clinical tests. The Rasch model was used to explore the questionnaires' psychometric properties and correlation and multiple linear regression analyses were used to explore the relationship between altered body perception and clinical status. The FreBAQ appears unidimensional with no redundant items, has minimal ceiling and floor effects, acceptable internal consistency, was functional on the category rating scale, and was not biased by demographic or clinical variables. FreBAQ scores were correlated with sensitivity, distress, and beliefs and were uniquely associated with pain and disability. PERSPECTIVE: Several lines of evidence suggest that body perception might be disturbed in people with chronic low back pain, possibly contributing to the condition and offering a potential target for treatment. The FreBAQ was developed as a quick and simple way of measuring back-specific body perception in people with chronic low back pain. The questionnaire appears to be a psychometrically sound way of assessing altered self-perception. The level of altered self-perception is positively correlated with pain intensity and disability as well as showing associations with psychological distress, pain catastrophization, fear avoidance beliefs, and lumbar pressure pain threshold. In this sample, it appears that altered self-perception might be a more important determinant of clinical severity than psychological distress, pain catastrophization, fear avoidance beliefs, or lumbar pressure pain threshold.

Pressure and cold pain threshold reference values in a large, young adult, pain-free population.

BACKGROUND AND AIMS: Currently there is a lack of large population studies that have investigated pain sensitivity distributions in healthy pain free people. The aims of this study were: (1) to provide sex-specific reference values of pressure and cold pain thresholds in young pain-free adults; (2) to examine the association of potential correlates of pain sensitivity with pain threshold values. METHODS: This study investigated sex specific pressure and cold pain threshold estimates for young pain free adults aged 21-24 years. A cross-sectional design was utilised using participants (n=617) from the Western Australian Pregnancy Cohort (Raine) Study at the 22-year follow-up. The association of site, sex, height, weight, smoking, health related quality of life, psychological measures and activity with pain threshold values was examined. Pressure pain threshold (lumbar spine, tibialis anterior, neck and dorsal wrist) and cold pain threshold (dorsal wrist) were assessed using standardised quantitative sensory testing protocols. RESULTS: Reference values for pressure pain threshold (four body sites) stratified by sex and site, and cold pain threshold (dorsal wrist) stratified by sex are provided. Statistically significant, independent correlates of increased pressure pain sensitivity measures were site (neck, dorsal wrist), sex (female), higher waist-hip ratio and poorer mental health. Statistically significant, independent correlates of increased cold pain sensitivity measures were, sex (female), poorer mental health and smoking. CONCLUSIONS: These data provide the most comprehensive and robust sex specific reference values for pressure pain threshold specific to four body sites and cold pain threshold at the dorsal wrist for young adults aged 21-24 years. Establishing normative values in this young age group is important given that the transition from adolescence to adulthood is a critical temporal period during which trajectories for persistent pain can be established. IMPLICATIONS: These data will provide an important research resource to enable more accurate profiling and interpretation of pain sensitivity in clinical pain disorders in young adults. The robust and comprehensive data can assist interpretation of future clinical pain studies and provide further insight into the complex associations of pain sensitivity that can be used in future research.

Low back pain and comorbidity clusters at 17 years of age: a cross-sectional examination of health-related quality of life and specific low back pain impacts.

PURPOSE: Comorbidities in adults negatively affect the course of low back pain (LBP). Little is known of the presence and/or impact of LBP comorbidities in adolescents. METHODS: Subjects from the Raine Study cohort at age 17 years (n = 1,391) provided self-report of diagnosed medical conditions/health complaints, health-related quality of life (36-Item Short Form Health Survey [SF-36]), lifetime experience of LBP, and specific LBP impacts (taking medication, missing school/work, interference with normal/physical activities). Latent class analysis was used to estimate clusters of comorbidities based on diagnosed disorders. Profiles of SF-36 and impact were examined between clusters. RESULTS: Four distinct comorbidity clusters were identified: cluster 1: Low probability of diagnosed LBP or any other medical condition (79.7%); cluster 2: High probability of diagnosed LBP and neck/shoulder pain, but a low probability of other diagnosed health conditions (9.6%); cluster 3: Moderate probability of diagnosed LBP and high probability of diagnosed anxiety and depression (6.9%); cluster 4: Moderate probability of diagnosed LBP and high probability of diagnosed behavioral and attention disorders (3.8%). The clusters had different SF-36 and LBP impact profiles, with clusters 3 and 4 having poorer SF-36 scores, and clusters 2 to 4 having greater risk for specific LBP impacts, than cluster 1. CONCLUSIONS: Identified comorbidity clusters support adolescent and adult studies reporting associations between LBP, other pain areas, psychological disorders, and disability. Tracking these clusters into adulthood may provide insight into health care utilization in later life, whereas identification of these individuals early in the life span may help optimize intervention opportunities.

Trajectories of childhood body mass index are associated with adolescent sagittal standing posture.

OBJECTIVES: To identify distinct age-related trajectory classes of body mass index (BMI) z-scores from childhood to adolescence, and to examine the association of these trajectories with measures of standing sagittal spinal alignment at 14 years of age. METHODS: Adolescents participating in the Western Australian Pregnancy Cohort (Raine) Study contributed data to the study (n=1 373). Age- and gender-specific z-scores for BMI were obtained from height and weight at the ages of 3, 5, 10 and 14 years. Latent class group analysis was used to identify six distinct trajectory classes of BMI z-score. At the age of 14 years, adolescents were categorised into one of four subgroups of sagittal spinal posture using k-means cluster analysis of photographic measures of lumbar lordosis, thoracic kyphosis and trunk sway. Regression modeling was used to assess the relationship between postural angles and subgroups, and different BMI trajectory classes, adjusting for gender. RESULTS: Six trajectory classes of BMI z-score were estimated: Very Low (4%), Low (24%), Average (34%), Ascending (6%), Moderate High (26%) and Very High (6%). The proportions of postural subgroups at age 14 were; Neutral (29%), Flat (22%), Sway (27%) and Hyperlordotic (22%). BMI trajectory class was strongly associated with postural subgroup, with significantly higher proportions of adolescents in the Very High, High and Ascending BMI trajectory classes displaying a Hyperlordotic or Sway posture than a Neutral posture at age 14. CONCLUSIONS: This prospective study provides evidence that childhood obesity, and how it develops, is associated with standing sagittal postural alignment in adolescence.

The effect of increased physical load during an active straight leg raise in pain free subjects.

PURPOSE: It has been proposed that pelvic girdle pain (PGP) subjects adopt a high load motor control strategy during the low load task of the active straight leg raise (ASLR). This study investigated this premise by observing the motor control patterns adopted by pain free subjects during a loaded ASLR (ASLR+PL). METHOD: Trunk muscle activation, intra-abdominal pressure, intra-thoracic pressure, pelvic floor motion, downward pressure of the non-lifted leg and respiratory rate were compared between resting supine, ASLR and ASLR+PL. Additionally, side-to-side comparisons were performed for ASLR+PL. RESULTS: Incremental increases in muscle activation were observed from resting supine to ASLR to ASLR+PL. During the ASLR+PL there was a simultaneous increase in intra-abdominal pressure with a decrease in intra-thoracic pressure, while respiratory fluctuation of these variables were maintained. The ASLR+PL also resulted in increased pelvic floor descent and greater downward pressure of the non-lifted leg. Trunk muscle activation was comparable between sides during ASLR+PL in all muscles except lower obliquus internus abdominis, which was more active on the leg lift side. CONCLUSION: Pain free subjects respond to an ASLR+PL by a general increase in anterior trunk muscle activation, but preserve the pattern of greater activation on the side of the leg lift observed during an unloaded ASLR. This contrasts to findings in PGP subjects who, despite having a high load strategy for performing an ASLR on the symptomatic side of the body, display equal bilateral activation of the anterior abdominal wall during the ASLR. This differentiates PGP subjects from pain free subjects, supporting the notion that PGP subjects have aberrant motor control patterns during an ASLR.

The effect of resisted inspiration during an active straight leg raise in pain-free subjects.

Alterations of respiratory patterns have been observed in pelvic girdle pain subjects during the active straight leg raise (ASLR). This study investigated how pain-free subjects coordinate motor control during an ASLR when this task is complicated by the addition of a respiratory challenge. Trunk muscle activation, intra-abdominal pressure, intra-thoracic pressure, pelvic floor motion, downward pressure of the non-lifted leg and respiratory rate were compared between resting supine, ASLR, breathing with inspiratory resistance (IR) and ASLR+IR. Subjects responded to ASLR+IR with an increase in the motor activation in the abdominal wall and chest wall compared to when ASLR and IR were performed in isolation. Activation of obliquus internus abdominis was greater on the side of the leg lift during the ASLR+IR, in comparison to symmetrical activation observed in the other abdominal wall muscles. The incremental increase of motor activity was associated with greater intra-abdominal pressure baseline shift when lifting the leg during ASLR+IR compared to ASLR. Individual variation was apparent in the form of the motor control patterns, mostly reflected in variable respiratory activation of the abdominal wall. The findings highlight the flexibility of the neuromuscular system in adapting to simultaneous respiratory and stability demands.

The effects of manual pelvic compression on trunk motor control during an active straight leg raise in chronic pelvic girdle pain subjects.

A sub-group of pelvic girdle pain (PGP) patients with a positive active straight leg raise (ASLR) responds positively to the application of external pelvic compression during the test. This study investigated the effect of this phenomenon on electromyographic (EMG) activity of the trunk muscles and intra-abdominal and intra-thoracic pressures in subjects with a unilateral sacroiliac joint (SIJ) pain disorder (n=12). All subjects reported reduced difficulty ratings during an ASLR with pelvic compression (paired t-test: p<0.001), yet no statistically significant changes in the muscle activation or pressure variables were found. However, visual inspection of the data revealed two divergent motor control strategies with the addition of compression. Seven subjects displayed characteristics of a decreased EMG profile, while in the other five subjects the EMG profile appeared to increase. As such this study provides preliminary evidence of two disparate patterns of motor control in response to the addition of pelvic compression to an ASLR. The findings may reflect different mechanisms, not only in the response to pelvic compression, but also of the underlying PGP disorder.

Motor control patterns during an active straight leg raise in chronic pelvic girdle pain subjects.

STUDY DESIGN: Repeated measures. OBJECTIVE: To investigate motor control (MC) patterns in chronic pelvic girdle pain (PGP) subjects during an active straight leg raise (ASLR). SUMMARY OF BACKGROUND DATA: The ASLR is a test used to assess load transference through the pelvis. Altered MC patterns have been reported in subjects with chronic PGP during this test. These patterns may impede efficient load transfer, while having the potential to impinge on respiratory function and/or to adversely affect the control of continence. METHODS: Twelve female subjects with chronic PGP were examined. Electromyography of the anterior abdominal wall, right chest wall and the scalene, intraabdominal pressure, intrathoracic pressure, respiratory rate, pelvic floor kinematics, and downward leg pressure of the nonlifted leg were compared between an ASLR lifting the leg on the affected side of the body versus the nonaffected side. RESULTS: Performing an ASLR lifting the leg on the affected side of the body resulted in a predominant MC pattern of bracing through the abdominal wall and the chest wall. This was associated with increased baseline shift in intraabdominal pressure and depression of the pelvic floor when compared with an ASLR lifting the leg on the nonaffected side. CONCLUSION: This MC pattern, identified during an ASLR on the affected side of the body, has the potential to be a primary mechanism driving ongoing pain and disability in chronic PGP subjects.

Motor control patterns during an active straight leg raise in pain-free subjects.

STUDY DESIGN: Repeated measures. OBJECTIVE: To investigate motor control (MC) patterns of normal subjects during the low level physical load of the active straight leg raise (ASLR). SUMMARY OF BACKGROUND DATA: Aberrant MC patterns, as observed with the ASLR test, are considered to be a mechanism for ongoing pain and disability in subjects with chronic musculoskeletal pelvic girdle pain. These patterns may not only affect the provision of lumbopelvic stability, but also respiration and the control of continence. Greater understanding of MC patterns in pain-free subjects may improve the management of pelvic girdle pain. METHODS.: Fourteen pain-free nulliparous women were examined during the ASLR. Electromyography of the anterior abdominal wall, right chest wall and the anterior scaleni, intraabdominal pressure (IAP), intrathoracic pressure (ITP), respiratory rate, pelvic floor kinematics, and downward leg pressure of the nonlifted leg were compared between a left and right ASLR. RESULTS: There was greater activation of obliquus internus abdominis and obliquus externus abdominis on the side of the ASLR. The predominant pattern of activation for the chest wall was tonic activation during an ipsilateral ASLR, and phasic respiratory activation lifting the contralateral leg. Respiratory fluctuation of both IAP and ITP did not differ lifting either leg. The baseline shifts of these pressure variables in response to the physical demand of lifting the leg was also the same either side. There was no difference in respiratory rate, pelvic floor kinematics, or downward leg pressure. CONCLUSION: Pain-free subjects demonstrate a predominant pattern of greater ipsilateral tonic activation of the abdominal wall and chest wall on the side of the ASLR. This was achieved with minimal apparent disruption to IAP and ITP. The findings of this study demonstrate the plastic nature of the abdominal cylinder and the flexibility of the neuromuscular system in controlling load transference during an ASLR.

Neck-shoulder muscle activity in general and task-specific resting postures of symptomatic computer users with chronic neck pain.

Past research on work-related musculoskeletal disorders (WMSD) has frequently examined the activity of neck-shoulder muscles such as upper trapezius (UT) and cervical erector spinae (CES) during typing tasks. Increased electromyographic activity in these postural stabilising muscles has been consistently found in chronic neck pain patients under different physically stressful conditions. The present study compared muscle activity when female office workers with chronic neck pain (n=39) and asymptomatic controls (n=34) adopted two resting postures: (1) with hands on laps versus; and (2) hands on a keyboard. Resting hands on keyboard elicited significantly increased muscle activity in the right UT of subjects with high discomforts (n=22), similar to that observed during actual typing. In contrast, the asymptomatic controls showed no difference in muscle activity between the resting postures. This result suggested that altered muscle activation patterns were triggered by some anticipatory task demand associated with a task-specific position in some individuals.

EMG median frequency changes in the neck-shoulder stabilizers of symptomatic office workers when challenged by different physical stressors.

The problem of work-related neck and upper limb disorders among computer users has been reported extensively in the literature, and commonly cited risk factors include static posture, speed and force of keyboard operation. The present study examined changes in median frequency (MF) of the neck-shoulder muscles in symptomatic and asymptomatic office workers when they were exposed to these three physical stressors. A quasi-experimental Case-Control design was used to examine MF changes in two groups of female office workers when they were subjected to controlled doses of computer work involving prolonged static posture, increased typing speed and increased typing force. The MF of four major neck-shoulder muscles were examined bilaterally and compared between groups. The MF changes over time-at-task did not clearly illustrate any muscle fatigue mechanism. However, Case Group consistently showed trends for higher MF than the Control Group, and this pattern was observed in response to all three physical stressors. The consistent group differences in MF suggest different muscle recruitment strategies between symptomatic and asymptomatic office workers. These results implied that symptomatic individuals had altered motor control, which may have important implications in understanding the etiology of work-related musculoskeletal disorders.

Reliability of EMG measurements for trunk muscles during maximal and sub-maximal voluntary isometric contractions in healthy controls and CLBP patients.

The purpose of this study was to compare the reliability of trunk muscle activity measured by means of surface electromyography (EMG) during maximal and sub-maximal voluntary isometric contractions (MVC/sub-MVC) over repeated trials within-day and between-days in healthy controls and patients with chronic low back pain (CLBP). Eleven volunteers (six controls and five CLBP patients) were assessed twice with a 1-week interval. Surface EMG signals were recorded bilaterally from six trunk muscles. Intra-class correlation coefficients (ICC) and standard error of measurement as a percentage of the grand mean (%SEM) were calculated. MVC and sub-MVC showed excellent within-day reliability in both healthy controls and CLBP patients (ICC mean 0.91; range 0.75-0.98; %SEM mean 4%; range 1-12%). Sub-MVC for both groups between-days showed excellent reliability (ICC mean 0.88; range 0.78-0.97; %SEM mean 7%; range 3-11%). The between-days MVC for both groups showed trends towards lower levels of reliability (ICC mean 0.70; range 0.19-0.99; %SEM mean 17%; range 4-36%) when compared to sub-MVC. Findings of the study provide evidence that sub-MVC are preferable for amplitude normalisation when assessing EMG signals of trunk muscles between-days.