Darren Beales

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.

Low back pain in 17 year olds has substantial impact and represents an important public health disorder: a cross-sectional study

BackgroundPrevalence of low back pain (LBP) rises rapidly during adolescence, reaching adult levels by the age of 18. It has been suggested that adolescent LBP is benign with minimal impact, despite limited evidence.MethodsThe aim of this study was to investigate the impact of LBP and the influence of chronicity, gender and presence of other spinal pain comorbidities at age 17. Subjects (n = 1283) were categorised according to experiencing current and chronic LBP, gender and presence of other areas of spinal pain. LBP impact was ascertained via questions regarding seeking professional assistance, using medication, missing school/work, limited normal or recreational physical activity and health related quality of life (HRQOL).Results12.3% of participants reported current but not chronic LBP, while 19.9% reported current chronic LBP. LBP was more commonly reported by females than males. Other spinal pain comorbidities were common in the LBP groups. Impact was greater in subjects with chronic LBP, in females and in those with other spinal pain comorbidities.ConclusionLBP, and particularly chronic LBP, has a significant negative impact at 17 years. It is commonly associated with care seeking, medication use, school absenteeism, and reduced HRQOL. These findings support that adolescent LBP is an important public health issue that requires attention.

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.

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.

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.

Characteristics of chronic non-specific musculoskeletal pain in children and adolescents attending a rheumatology outpatients clinic: a cross-sectional study

BackgroundChronic non-specific musculoskeletal pain (CNSMSP) may develop in childhood and adolescence, leading to disability and reduced quality of life that continues into adulthood. The purpose of the study was to build a biopsychosocial profile of children and adolescents with CNSMSP.MethodsCNSMSP subjects (n = 30, 18 females, age 7-18) were compared with age matched pain free controls across a number of biopsychosocial domains.ResultsIn the psychosocial domain CNSMSP subjects had increased levels of anxiety and depression, and had more somatic pain complaints. In the lifestyle domain CNSMSP subjects had lower physical activity levels, but no difference in television or computer use compared to pain free subjects. Physically, CNSMSP subjects tended to sit with a more slumped spinal posture, had reduced back muscle endurance, increased presence of joint hypermobility and poorer gross motor skills.ConclusionThese findings support the notion that CNSMSP is a multidimensional biopsychosocial disorder. Further research is needed to increase understanding of how the psychosocial, lifestyle and physical factors develop and interact in CNSMSP.

Association of Biopsychosocial Factors With Degree of Slump in Sitting Posture and Self-Report of Back Pain in Adolescents: A Cross-Sectional Study

Background Conflicting evidence exists regarding relationships among sitting posture, factors that influence sitting posture, and back pain. This conflicting evidence may partially be due to the presence of multiple and overlapping factors associated with both sitting posture and back pain. Objective The purpose of this study was to determine whether the degree of slump in sitting was associated with sex and other physical, lifestyle, or psychosocial factors. Additionally, the relationship between the report of back pain made worse by sitting and the degree of slump in sitting and other physical, lifestyle, or psychosocial factors was investigated. Design This was a cross-sectional study. Methods Adolescents (n=1,596) completed questionnaires to determine lifestyle and psychosocial profiles and the experience of back pain. Sagittal sitting posture, body mass index (BMI), and back muscle endurance (BME) were recorded. Standing posture subgroup categorization was determined. Results Multivariate analysis revealed that the most significant factor associated with the degree of slump in sitting was male sex, followed by non-neutral standing postures, lower perceived self-efficacy, lower BME, greater television use, and higher BMI. Multivariable analysis indicated poorer Child Behaviour Checklist scores were the strongest correlate of report of back pain made worse by sitting, whereas degree of slump in sitting, female sex, and BME were more weakly related. Limitations Causality cannot be determined from this cross-sectional study, and 60% of sitting posture variation was not explained by the measured variables. Conclusions Slump in sitting was associated with physical correlates, as well as sex, lifestyle, and psychosocial factors, highlighting the complex, multidimensional nature of usual sitting posture in adolescents. Additionally, this study demonstrated that a greater degree of slump in sitting was only weakly associated with adolescent back pain made worse by sitting after adjustment for other physical and psychosocial factors.

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.

Somatosensory nociceptive characteristics differentiate subgroups in people with chronic low back pain: a cluster analysis

Abstract The objectives of this study were to explore the existence of subgroups in a cohort with chronic low back pain (n = 294) based on the results of multimodal sensory testing and profile subgroups on demographic, psychological, lifestyle, and general health factors. Bedside (2-point discrimination, brush, vibration and pinprick perception, temporal summation on repeated monofilament stimulation) and laboratory (mechanical detection threshold, pressure, heat and cold pain thresholds, conditioned pain modulation) sensory testing were examined at wrist and lumbar sites. Data were entered into principal component analysis, and 5 component scores were entered into latent class analysis. Three clusters, with different sensory characteristics, were derived. Cluster 1 (31.9%) was characterised by average to high temperature and pressure pain sensitivity. Cluster 2 (52.0%) was characterised by average to high pressure pain sensitivity. Cluster 3 (16.0%) was characterised by low temperature and pressure pain sensitivity. Temporal summation occurred significantly more frequently in cluster 1. Subgroups were profiled on pain intensity, disability, depression, anxiety, stress, life events, fear avoidance, catastrophizing, perception of the low back region, comorbidities, body mass index, multiple pain sites, sleep, and activity levels. Clusters 1 and 2 had a significantly greater proportion of female participants and higher depression and sleep disturbance scores than cluster 3. The proportion of participants undertaking <300 minutes per week of moderate activity was significantly greater in cluster 1 than in clusters 2 and 3. Low back pain, therefore, does not appear to be homogeneous. Pain mechanisms relating to presentations of each subgroup were postulated. Future research may investigate prognoses and interventions tailored towards these subgroups.

Differing Psychologically Derived Clusters in People With Chronic Low Back Pain are Associated With Different Multidimensional Profiles.

Objectives:To explore the existence of subgroups in a cohort with chronic low back pain (n=294) based upon data from multiple psychological questionnaires, and profile subgroups on data from multiple dimensions. Methods:Psychological questionnaires considered as indicator variables entered into latent class analysis included: Depression, Anxiety, Stress scales, Thought Suppression and Behavioural Endurance subscales (Avoidance Endurance questionnaire), Chronic Pain Acceptance Questionnaire (short-form), Pain Catastrophising Scale, Pain Self-Efficacy Questionnaire, and Fear-Avoidance Beliefs Questionnaire. Multidimensional profiling of derived clusters included: demographics, pain characteristics, pain responses to movement, behaviors associated with pain, body perception, pain sensitivity, and health and lifestyle factors. Results:Three clusters were derived. Cluster 1 (23.5%) was characterized by low Cognitive and Affective Questionnaire scores, with the exception of fear-avoidance beliefs. Cluster 2 (58.8%) was characterized by relatively elevated thought suppression, catastrophizing, and fear-avoidance beliefs, but lower pain self-efficacy, depression, anxiety, and stress. Cluster 3 (17.7%) had the highest scores across cognitive and affective questionnaires.Cluster 1 reported significantly lower pain intensity and bothersomeness than other clusters. Disability, stressful life events, and low back region perceptual distortion increased progressively from cluster 1 to cluster 3, whereas mindfulness progressively decreased. Clusters 2 and 3 had more people with an increase in pain following repeated forward and backward spinal bending, and more people with increasing pain following bending, than cluster 1. Cluster 3 had significantly greater lumbar pressure pain sensitivity, more undiagnosed comorbid symptoms, and more widespread pain than other clusters. Discussion:Clinical implications relating to presentations of each cluster are postulated.