Genetic variation in the beta-2 adrenergic receptor is associated with chronic musculoskeletal complaints in adolescents.

BACKGROUND: There is significant evidence to suggest that psychological and stress-related factors are important predictors of the onset of chronic widespread pain (CWP) and fibromyalgia (FM). The hypothalamic-pituitary-adrenal axis, together with the efferent sympathetic/adrenomedullary system, influence all body organs (including muscles) during short- and long-term threatening stimuli. The aim of this study was to investigate the relationship between genetic variants in adrenergic candidate genes and chronic musculoskeletal complaints (MSCs) in adolescents. METHODS: Adolescents from the Western Australian Pregnancy (Raine) Cohort attending the 17-year cohort review completed a questionnaire containing a broad range of psychosocial factors and pain assessment (n = 1004). Blood samples were collected for DNA extraction and genotyping. Genotype data was obtained for 14 single nucleotide polymorphisms (SNPs) in two candidate genes - beta-2 adrenergic receptor (ADRB2) and catecholamine-O-methyltransferase (COMT). Haplotypes were reconstructed for all individuals with genotype data. RESULTS AND CONCLUSION: Both female gender and poor mental health were associated with (1) an increased risk for chronic, disabling comorbid neck and low back pain (CDCP); and (2) an increase in the number of areas of pain. Of the 14 SNPs evaluated, only SNP rs2053044 (ADRB2, recessive model) displayed an association with CDCP [odds ratio (OR) = 2.49; 95% confidence interval (CI) = 1.25, 4.98; p = 0.01] and pain in three to four pain areas in the last month (OR = 1.86; 95% CI = 1.13, 3.06; p = 0.02). These data suggest that genetic variants in ADRB2 may be involved in chronic MSCs.

'I am absolutely shattered': the impact of chronic low back pain on Australian Aboriginal people.

BACKGROUND: Aboriginal people in Australia have been uniquely identified as less susceptible to chronic low back pain (CLBP) disability when compared to non-Aboriginal populations, reportedly due to cultural beliefs about pain. A qualitative, culturally secure research approach was used to explore this assumption. METHODS: In-depth interviews were undertaken with 32 Aboriginal men and women with CLBP in regional and remote areas of Western Australia. Interviews were conducted collaboratively with male and female Aboriginal co-investigators, and with the support of local Aboriginal community organizations. A primary focus was to investigate the impact of CLBP from the perspective of Aboriginal people living with the condition. RESULTS: The experience of CLBP was found to be multidimensional, impacting on activities of daily life, employment, sport and family participation, emotional and cultural well-being. CONCLUSIONS: Contrary to previous assumptions, CLBP is profoundly disabling for some Aboriginal people and a priority health concern. Issues of gender, cultural obligations and the emotional consequences of CLBP are important consideration for health care. These findings, and the contextual approach used to gain an in-depth understanding of CLBP, may be relevant to populations elsewhere.

Neck/shoulder pain is more strongly related to depressed mood in adolescent girls than in boys.

A cross-sectional study of 1258, 14 year old girls and boys used self-report and physical examination measures to assess neck/shoulder pain in the last month, depressed mood, physical fitness, body composition, self-efficacy, global self-worth, family functioning and social advantage. The data was used to compare the relationship between depressed mood and neck/shoulder pain (NSP) in adolescent girls and boys. The prevalence of NSP in girls (34%, 211/621) was significantly greater than in boys (21%, 134/637; p < .001). After controlling for covariates, girls with medium (OR = 4.28; CI = 2.31-7.92; p < .001) and high depressed mood (OR = 8.63; CI = 4.39-16.98; p < .001) were significantly more likely to report NSP than girls with low depressed mood. Depressed mood was also a significant correlate of NSP in boys after controlling for covariates, although the association was substantially weaker (OR = 2.44; CI = 1.29-4.61; p < .001). After controlling for relevant biological, psychological and social covariates, depressed mood was a significant correlate of NSP in both sexes; but the association between depressed mood and NSP was significantly stronger for girls than for boys.

Integration of subclassification strategies in randomised controlled clinical trials evaluating manual therapy treatment and exercise therapy for non-specific chronic low back pain: a systematic review.

BACKGROUND: There is lack of evidence for specific treatment interventions for patients with non-specific chronic low back pain (NSCLBP) despite the substantial amount of randomised controlled clinical trials evaluating treatment outcome for this disorder. HYPOTHESIS: It has been hypothesised that this vacuum of evidence is caused by the lack of subclassification of the heterogeneous population of patients with chronic low back pain for outcome research. STUDY DESIGN: A systematic review. METHODS: A systematic review with a meta-analysis was undertaken to determine the integration of subclassification strategies with matched interventions in randomised controlled clinical trials evaluating manual therapy treatment and exercise therapy for NSCLBP. A structured search for relevant studies in Embase, Cinahl, Medline, PEDro and the Cochrane Trials Register database, followed by hand searching all relevant studies in English up to December 2008. RESULTS: Only 5 of 68 studies (7.4%) subclassified patients beyond applying general inclusion and exclusion criteria. In the few studies where classification and matched interventions have been used, our meta-analysis showed a statistical difference in favour of the classification-based intervention for reductions in pain (p=0.004) and disability (p=0.0005), both for short-term and long-term reduction in pain (p=0.001). Effect sizes ranged from moderate (0.43) for short term to minimal (0.14) for long term. CONCLUSION: A better integration of subclassification strategies in NSCLBP outcome research is needed. We propose the development of explicit recommendations for the use of subclassification strategies and evaluation of targeted interventions in future research evaluating NSCLBP.

Inter-examiner reliability of a classification system for patients with non-specific low back pain.

There is a lack of studies examining whether mechanism-based classification systems (CS) acknowledging biological, psychological and social dimensions of long-lasting low back pain (LBP) disorders can be performed in a reliable manner. The purpose of this paper was to examine the inter-tester reliability of clinicians' ability to independently classify patients with non-specific LBP (NSLBP), utilising a mechanism-based classification method. Twenty-six patients with NSLBP underwent an interview and full physical examination by four different physiotherapists. Percentage agreement and Kappa coefficients were calculated for six different levels of decision making. For levels 1-4, percentage agreement had a mean of 96% (range 75-100%). For the primary direction of provocation Kappa and percentage agreement had a mean between the four testers of 0.82 (range 0.66-0.90) and 86% (range 73-92%) respectively. At the final decision making level, the scores for detecting psychosocial influence gave a mean Kappa coefficient of 0.65 (range 0.57-0.74) and 87% (range 85-92%). The findings suggest that the inter-tester reliability of the system is moderate to substantial for a range of patients within the NSLBP population in line with previous research.

The inter-examiner reliability of a classification method for non-specific chronic low back pain patients with motor control impairment.

The importance of classifying chronic low back pain (LBP) patients into homogeneous sub-groups has recently been emphasized. This paper reports on two studies examining clinicians ability to agree independently on patients' chronic LBP classification, using a novel classification system (CS) proposed by O'Sullivan. In the first study, a sub-group of 35 patients with non-specific chronic LBP were independently classified by two 'expert' clinicians. Almost perfect agreement (kappa-coefficient 0.96; %-of-agreement 97%) was demonstrated. In the second study, 13 clinicians from Australia and Norway were given 25 cases (patients' subjective information and videotaped functional tests) to classify. Kappa-coefficients (mean 0.61, range 0.47-0.80) and %-of-agreement (mean 70%, range 60-84%) indicated substantial reliability. Increased familiarity with the CS improved reliability. These studies demonstrate the reliability of this multi-dimensional mechanism-based CS and provide essential evidence in a multi-step validation process. A fully validated CS will have significant research and clinical application.

Lumbar segmental 'instability': clinical presentation and specific stabilizing exercise management.

Lumbar segmental instability is considered to represent a significant sub-group within the chronic low back pain population. This condition has a unique clinical presentation that displays its symptoms and movement dysfunction within the neutral zone of the motion segment. The loosening of the motion segment secondary to injury and associated dysfunction of the local muscle system renders it biomechanically vulnerable in the neutral zone. The clinical diagnosis of this chronic low back pain condition is based on the report of pain and the observation of movement dysfunction within the neutral zone and the associated finding of excessive intervertebral motion at the symptomatic level. Four different clinical patterns are described based on the directional nature of the injury and the manifestation of the patient's symptoms and motor dysfunction. A specific stabilizing exercise intervention based on a motor learning model is proposed and evidence for the efficacy of the approach provided.

Altered abdominal muscle recruitment in patients with chronic back pain following a specific exercise intervention.

The efficacy of specific exercise interventions that advocate training the co-contraction of the deep abdominal muscles with lumbar multifidus for treating chronic back pain conditions has not been tested. A randomized controlled trial involving 42 subjects with a specific chronic back pain condition investigated whether this form of intervention results in changes to the ratio of activation of the internal oblique relative to the rectus abdominis. Data were collected before and after the intervention, using surface electromyography, while subjects performed different abdominal maneuvers. Subjects were randomly allocated to either a specific exercise group or control group. Following intervention, the specific exercise group showed a significant (p < 0.05) increase in the ratio of activation of the internal oblique relative to the rectus abdominis. The control group showed no significant change. The study findings provide evidence that the conscious and automatic patterns of abdominal muscle activation can be altered by specific exercise interventions.

Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis or spondylolisthesis.

STUDY DESIGN: A randomized, controlled trial, test--retest design, with a 3-, 6-, and 30-month postal questionnaire follow-up. OBJECTIVE: To determine the efficacy of a specific exercise intervention in the treatment of patients with chronic low back pain and a radiologic diagnosis of spondylolysis or spondylolisthesis. SUMMARY OF BACKGROUND DATA: A recent focus in the physiotherapy management of patients with back pain has been the specific training of muscles surrounding the spine (deep abdominal muscles and lumbar multifidus), considered to provide dynamic stability and fine control to the lumbar spine. In no study have researchers evaluated the efficacy of this intervention in a population with chronic low back pain where the anatomic stability of the spine was compromised. METHODS: Forty-four patients with this condition were assigned randomly to two treatment groups. The first group underwent a 10-week specific exercise treatment program involving the specific training of the deep abdominal muscles, with co-activation of the lumbar multifidus proximal to the pars defects. The activation of these muscles was incorporated into previously aggravating static postures and functional tasks. The control group underwent treatment as directed by their treating practitioner. RESULTS: After intervention, the specific exercise group showed a statistically significant reduction in pain intensity and functional disability levels, which was maintained at a 30-month follow-up. The control group showed no significant change in these parameters after intervention or at follow-up. SUMMARY: A "specific exercise" treatment approach appears more effective than other commonly prescribed conservative treatment programs in patients with chronically symptomatic spondylolysis or spondylolisthesis.