Effect of experimental low back pain on neuromuscular control of the trunk in healthy volunteers and patients with chronic low back pain

Studies of electromyographic (EMG) activity and lumbopelvic rhythm have led to a better understanding of neuromuscular alterations in chronic low back pain (cLBP) patients. Whether these changes reflect adaptations to chronic pain or are induced by acute pain is still unclear. This work aimed to assess the effects of experimental LBP on lumbar erector spinae (LES) EMG activity and lumbopelvic kinematics during a trunk flexion–extension task in healthy volunteers and LBP patients. The contribution of disability to these effects was also examined. Twelve healthy participants and 14 cLBP patients performed flexion–extension tasks in three conditions; control, innocuous heat and noxious heat, applied on the skin over L5 or T7. The results indicated that noxious heat at L5 evoked specific increases in LES activity during static full trunk flexion and extension, irrespective of participants’ group. Kinematic data suggested that LBP patients adopted a different movement strategy than controls when noxious heat was applied at the L5 level. Besides, high disability was associated with less kinematic changes when approaching and leaving full flexion. These results indicate that experimental pain can induce neuromechanical alterations in cLBP patients and healthy volunteers, and that higher disability in patients is associated with decreased movement pattern changes.     

Supplementation with alkaline minerals reduces symptoms in patients with chronic low back pain

The cause of low back pain is heterogeneous, it has been hypothesised that a latent chronic acidosis might contribute to these symptoms. It was tested whether a supplementation with alkaline minerals would influence symptoms in patients with low back pain symptoms. In an open prospective study 82 patients with chronic low back pain received daily 30 g of a lactose based alkaline multimineral supplement (Basica) over a period of 4 weeks in addition to their usual medication. Pain symptoms were quantified with the "Arhus low back pain rating scale" (ARS). Mean ARS dropped highly significant by 49% from 41 to 21 points after 4 weeks supplemention. In 76 out of 82 patients a reduction in ARS was achieved by the supplementation. Total blood buffering capacity was significantly increased from 77.69 +/- 6.79 to 80.16 +/- 5.24 mmol/L (mean +/- SEM, n = 82, p < 0.001) and also blood pH rose from 7.456 +/- 0.007 to 7.470 +/- 0.007 (mean +/- SEM, n = 75, p < 0.05). Only intracellular magnesium increased by 11% while other intracellular minerals were not significantly changed in sublingual tissue as measured with the EXA-test. Plasma concentrations of potassium, calcium, iron, copper, and zinc were within the normal range and not significantly influenced by the supplementation. Plasma magnesium was slightly reduced after the supplemenation (-3%, p < 0.05). The results show that a disturbed acid-base balance may contribute to the symptoms of low back pain. The simple and safe addition of an alkaline multimineral preparate was able to reduce the pain symptoms in these patients with chronic low back pain.     

Chronic low back pain patients walk with locally altered spinal kinematics

Various studies have reported alterations of spinal kinematics in patients with chronic low back pain (CLBP) during gait. However, while recent findings stressed the importance of multi-segment analysis, most of prior gait studies modelled the lumbar spine as one segment, when it was not the entire trunk that was considered as a single segment. Therefore, there is a need for comprehensive multi-segment research that could improve our understanding of CLBP pathomechanism and thus possibly contribute to better care for CLBP. This study aimed at characterizing the angle patterns at the lower lumbar (LLS), upper lumbar (ULS), lower thoracic (LTS) and upper thoracic (UTS) joints in the three anatomical planes and at comparing CLBP patients and asymptomatic subjects. Spinal kinematics of 11 CLBP patients and 11 controls was measured using a marker-based motion capture system and described according to a previously proposed multi-segment biomechanical model. Characteristic patterns were observed at the UTS, LTS and ULS joints in the transverse plane and at the UTS, ULS and LLS joints in the frontal plane. CLBP patients walked with smaller frontal-plane LLS range of motion than controls. The results also suggested that patients had more asymmetrical LTS motion in the transverse plane. In conclusion, this work extended prior literature by showing specific CLBP-related alterations in multi-segment spinal kinematics during gait. Further research is necessary to understand the factors influencing kinematics alterations and how treatment strategies might improve motor behaviour in CLBP patients.     

The impact of wool in the patients with chronic non-specific low back pain

The aim was to assess the effect of wool underwear use in patients with chronic non specific low back pain. The study employed two-group, experimental design. A total of 48 patients with chronic non specific low back pain were selected for the study. They were distributed into two groups: a control group and a treatment group. The 24 patients in each group were randomly selected and the compositions of the two groups. The patients in the treatment group wore woolen underwear during the experimental period of 2 month. All patients were assessed at the beginning the trial (pre-test) and the end of 8th (post-test) week. Data were collected using the visual analogue pain scale, Oswestry Disability Index and Schober test measurements. Patients in the treatment group reported significant improvements in their conditions including a reduction in pain levels and Oswestry Disability Index, and Schober test measurements increased (p<0.001). Patients with chronic non-specific low back pain who wore wool underwear experienced significant improvements in pain intensity, disability, and lower back flexibility.     

Reliability of posturographic measurements in the assessment of impaired sensorimotor function in chronic low back pain

The evaluation of postural stability using posturography could be both a valuable functional diagnostic and treatment outcome monitoring tool in rehabilitation practice of patients with chronic low back pain (cLBP). No evidence, however, seems to exist, whether or not such posturographic measures are reliable in these patients and therefore clinically and scientifically useful. The aims of this study were manifold and aimed at investigating (1) differences of posturographic measures between cLBP patients and healthy controls (HCs), (2) short- (intrasession-) and long-term (intersession-) reliability of these measurements, and (3) the relationship between both pain intensity and test-related feelings and significant learning effects of the posturographic measures in cLBP.A total of 32 cLBP patients and 19 non-sportive HCs completed (1) comprehensive clinical examination, (2) quantitative posturographic testing (SMART EquiTest, Neurocom International, Clackamas, Oregon) that included all the sensory organisation test (SOT), the motor control test (MCT) and the adaptation test (ADT) and (3) psychological ratings of pain as well as posturographic test related personal feelings and fear associated beliefs. Of these, 22 cLBP patients who received no therapy repeated all measurements and examinations on a second day, 2–3 weeks later.Results revealed significant differences between cLBP patients and HCs in the more demanding postural test conditions of the SOT and the SOT composite score only. Intra-session reliability testing demonstrated significant improvements of the SOT and ADT measures for both HCs and cLBP patients. Results of long-term reliability testing showed significant improvements of the more challenging SOT conditions and SOT composite score. VAS ratings of pain, feelings and fear associated beliefs were not associated with such longitudinal changes.ConclusionOur findings suggest that the significant learning effects observed for the SOT conditions may limit the clinical application of SMART EquiTest postural stability measures for cLBP patients in rehabilitation everyday practice. Further development in software processing will be necessary to identify new postural parameters that are less prone to learning effects.     

Enhanced sensitivity to punctate painful stimuli in female patients with chronic low back pain

Background

Chronic fatigue and inactivity are prevalent problems among individuals with multiple sclerosis (MS) and may independently or interactively have detrimental effects on quality of life and ability to participate in life roles. However, no studies to date have systematically evaluated the benefits of an intervention for both managing fatigue and promoting physical activity in individuals with MS. This study involves a randomized controlled trial to examine the effectiveness of a telehealth intervention that supports individuals with MS in managing fatigue and increasing physical activity levels.

Methods/Design

A randomly-allocated, three-parallel group, time-series design with a social support program serving as the control group will be used to accomplish the purpose of the study. Our goal is to recruit 189 ambulatory individuals with MS who will be randomized into one of three telehealth interventions: (1) a contact-control social support intervention, (2) a physical activity-only intervention, and (3) a physical activity plus fatigue management intervention. All interventions will last 12?weeks and will be delivered entirely over the phone. Our hypothesis is that, in comparison to the contact-control condition, both the physical activity-only intervention and the physical activity plus fatigue management intervention will yield significant increases in physical activity levels as well as improve fatigue and health and function, with the physical activity plus fatigue management intervention yielding significantly larger improvements. To test this hypothesis, outcome measures will be administered at Weeks 1, 12, and 24. Primary outcomes will be the Fatigue Impact Scale, the Godin Leisure-Time Exercise Questionnaire (GLTEQ), and Actigraph accelerometers. Secondary outcomes will include the SF-12 Survey, Mental Health Inventory, Multiple Sclerosis Impact Scale, the Community Participation Indicator, and psychosocial constructs (e.g., self-efficacy).

Discussion

The proposed study is novel, in that it represents a multi-disciplinary effort to merge two promising lines of research on MS: fatigue management and physical activity promotion. Collectively, the proposed study will be the largest randomized controlled trial to examine the effects of a lifestyle physical activity intervention in people with MS.

Trial registration

NCT01572714     

Mechanical demands on the lower back in patients with non-chronic low back pain during a symmetric lowering and lifting task

There is limited information in the literature related to the lower back loading in patients with LBP, particularly those with non-chronic LBP. Toward addressing such a research gap, a case-control study was conducted to explore the differences in lower back mechanical loads between a group of females (n = 19) with non-chronic, non-specific LBP and a group of asymptomatic females (n = 19). The differences in lower back mechanical loads were determined when participants completed one symmetric lowering and lifting of a 4.5 kg load at their preferred cadence. The axial, shearing, and moment components of task demand at the time of peak moment component as well as measures of peak trunk kinematics were analyzed. Patient vs. asymptomatic group performed the task with smaller peak thoracic rotation and peak lumbar flexion. While no differences in the moment component of task demand on the lower back between the patients and controls were found, the shearing (40–50 age group) and axial components of task demand were, respectively, larger and smaller in patients vs. controls. Whether alterations in lower back loads in patients with non-chronic LBP are in response to pain or preceded the pain, the long-term exposure to abnormal lower back mechanics may adversely affect spinal structure and increase the likelihood of further injury or pain. Therefore, the underlying reason(s) as well as the potential consequence(s) of such altered lower back mechanics in patients with non-chronic LBP should to be further investigated.     

Neuromuscular adaptations predict functional disability independently of clinical pain and psychological factors in patients with chronic non-specific low back pain

Patients with chronic low back pain exhibit characteristics such as clinical pain, psychological symptoms and neuromuscular adaptations. The purpose of this study was to determine the independent contribution of clinical pain, psychological factors and neuromuscular adaptations to disability in patients with chronic low back pain. Clinical pain intensity, pain catastrophizing, fear-avoidance beliefs, anxiety, neuromuscular adaptations to chronic pain and neuromuscular responses to experimental pain were assessed in 52 patients with chronic low back pain. Lumbar muscle electromyographic activity was assessed during a flexion–extension task (flexion relaxation phenomenon) to assess both chronic neuromuscular adaptations and neuromuscular responses to experimental pain during the task. Multiple regressions showed that independent predictors of disability included neuromuscular adaptations to chronic pain (β = 0.25, p = 0.006, sr² = 0.06), neuromuscular responses to experimental pain (β = −0.24, p = 0.011, sr² = 0.05), clinical pain intensity (β = 0.28, p = 0.002, sr² = 0.08) and psychological factors (β = 0.58, p < 0.001, sr² = 0.32). Together, these predictors accounted for 65% of variance in disability (R² = 0.65 p < 0.001). The current investigation revealed that neuromuscular adaptations are independent from clinical pain intensity and psychological factors, and contribute to inter-individual differences in patients’ disability. This suggests that disability, in chronic low back pain patients, is determined by a combination of factors, including clinical pain, psychological factors and neuromuscular adaptations.     

Reliability of surface electromyography for the gluteus medius muscle during gait in people with and without chronic nonspecific low back pain

The purpose of this study was to determine the intratester reliability of surface electromyography (EMG) assessment of the gluteus medius muscle in healthy people and people with chronic nonspecific low back pain (CNLBP) during barefoot walking. Gluteus medius muscle activity was measured twice in 40 people without and 30 people with CNLBP approximately 7 days apart. Walking gluteus medius muscle activity was normalised to maximal voluntary isometric contractions during side-lying hip abduction with manual resistance. Good intratester reliability (ICC > 0.75) was found for mean, peak, and peak to peak amplitude for healthy people. Only mean amplitude demonstrated good intratester reliability in those with CNLBP. Peak amplitude and peak to peak amplitude of the gluteus medius muscle of those with CNLBP, and the time of peak amplitude in both groups, demonstrated moderate reliability (ICC ranged from 0.50 to 0.58). Moderate to large standard error of measurement and minimal detectable change values were reported for outcome measurements. These results suggest that potentially large levels of random error can occur between sessions. Future research can build on this study for those with pathology and attempt to establish change values for EMG that are clinically meaningful.     

Influence of comorbidity with depression on interdisciplinary therapy: outcomes in patients with chronic low back pain

Introduction  

Our previous work showed higher tumour necrosis factor (TNF)-α levels in patients with chronic low back pain (cLBP) compared to healthy controls. However, patients with depression as a comorbidity did not have higher TNF-α levels in comparison to patients without depression. In this study we investigated the influence of depression on therapy outcomes such as TNF-α serum levels, pain intensity and back function in patients with cLBP. Our hypothesis was that patients with both cLBP and depression benefit no less than patients with cLBP alone from the multidisciplinary pain therapy.     

Trunk muscle onset and cessation in golfers with and without low back pain

The knowledge of the onset and cessation timing of the paraspinal muscles that surround the lumbar spine is an important area of research for the understanding of low back pain. This study examined the timing of the erector spinae and external oblique muscle activity in a group of golfers with and without low back pain. The study compared the results of surface electromyography measurements for two groups of golfers. Twelve male golfers who had reported a mild or greater level of pain in the lower back that was experienced while playing golf were examined. A further fifteen male golfers who had reported no history of lower back pain in the previous 12 months were recruited as controls. The results showed that the low-back-pain golfers switched on their erector spinae muscle significantly in advance of the start of the backswing. This finding was not evident in the group who did not have low back pain symptoms. Low-back-pain golfers, therefore, may use the erector spinae muscle as a primary spinal stabiliser instead of the stronger deeper muscles such as transversus abdominis and multifidus. These results may have important implications for conditioning programmes for golfers with low back pain.     

The reliability and validity for Japanese type 2 diabetes patients of the Japanese version of the acceptance and action diabetes questionnaire

Background

The purpose of this study was to determing which psychological traits of Japanese type 2 diabetes patients would provide reliability and validity to the Japanese version of the Acceptance and Action Diabetes Questionnaire (AADQ-J).

Methods

Various questionnaires were administered to type 2 diabetes patients who were registered on the database of the research service provider; data from a total of 600 patients (mean?±?SD age was 57.50?±?9.87 years, female 21.83%) were analyzed.

Results

Three items were excluded because of psychometric concerns related to the original 11-item AADQ. Confirmation factor analyses revealed that the eight-item version demonstrated the best indicators of a goodness of fit. The questionnaire showed adequate internal consistency. The questionnaire demonstrated high measurement accuracy in broad trait values by the test information function of Item Response Theory. The questionnaire showed stronger positive correlations with self-care activities and HbA1c than with diabetes distress and depressive mood.

Conclusions

The eight-item Japanese version of AADQ has reliability and validity for type 2 diabetes patients.

     

Prognosis in patients with recent onset low back pain in Australian primary care: inception cohort study

Objective To estimate the one year prognosis and identify prognostic factors in cases of recent onset low back pain managed in primary care.Design Cohort study with one year follow-up.Setting Primary care clinics in Sydney, Australia.Participants An inception cohort of 973 consecutive primary care patients (mean age 43.3, 54.8% men) with non-specific low back pain of less than two weeks’ duration recruited from the clinics of 170 general practitioners, physiotherapists, and chiropractors.Main outcome measures Participants completed a baseline questionnaire and were contacted six weeks, three months, and 12 months after the initial consultation. Recovery was assessed in terms of return to work, return to function, and resolution of pain. The association between potential prognostic factors and time to recovery was modelled with Cox regression.Results The follow-up rate over the 12 months was more than 97%. Half of those who reduced their work status at baseline had returned to previous work status within 14 days (95% confidence interval 11 to 17 days) and 83% had returned to previous work status by three months. Disability (median recovery time 31 days, 25 to 37 days) and pain (median 58 days, 52 to 63 days) took much longer to resolve. Only 72% of participants had completely recovered 12 months after the baseline consultation. Older age, compensation cases, higher pain intensity, longer duration of low back pain before consultation, more days of reduced activity because of lower back pain before consultation, feelings of depression, and a perceived risk of persistence were each associated with a longer time to recovery.Conclusions In this cohort of patients with acute low back pain in primary care, prognosis was not as favourable as claimed in clinical practice guidelines. Recovery was slow for most patients. Nearly a third of patients did not recover from the presenting episode within a year.     

Controlled trial of mobilisation and manipulation for low back pain: hospital patients.

Ninety-four patients with non-specific lumbar pain referred to hospital rheumatology and orthopaedic clinics participated in a double-blind controlled trial comparing mobilisation and manipulation with placebo physiotherapy. Results were assessed immediately after the tratment course, two months later, and at one year. Many patients showed improvement, but in contrast to a study on general-practitioner patients with nonspecific back pain no definite advantage could be associated with mobilisation and manipulation. The benefits of mobilisation and manipulation for low back pain are probably restricted to hastening recovery in patients likely rapidly to improve spontaneously. Hence patients whose severity and duration of symptoms warrant specialist referral are less likely to benefit from the technique.     

Core stability exercises in individuals with and without chronic nonspecific low back pain

Marshall, PWM, Desai, I, and Robbins, DW. Core stability exercises in individuals with and without chronic nonspecific low back pain. J Strength Cond Res 25(12): 3404-3411, 2011-The aim of this study was to measure trunk muscle activity during several commonly used exercises in individuals with and without low back pain (LBP). Abdominal bracing was investigated as an exercise modification that may increase the acute training stimulus. After an initial familiarization session, 10 patients with LBP and 10 matched controls performed 5 different exercises (quadruped, side bridge, modified push-up, squat, shoulder flexion) with and without abdominal bracing. Trunk muscle activity and lumbar range of motion (LROM) were measured during all exercises. Muscle activity was measured bilaterally during each exercise from rectus abdominis (RA), external obliques (EO), and lumbar erector spinae (ES) with pairs of surface electrodes. Recorded signals were normalized to a percentage of maximal voluntary contractions performed for each muscle. The ES activity was lower for the LBP group during the quadruped (p < 0.05) and higher for RA and EO during the side bridge (p < 0.001), compared to for the healthy controls. Higher muscle activity was observed across exercises in an inconsistent pattern when abdominal bracing was used during exercise. The LROM was no different between groups for any exercise. The lack of worsening of symptoms in the LBP group and similar LROM observed between groups suggest that all exercises investigated in this study are of use in rehabilitating LBP patients. The widespread use of abdominal bracing in clinical practice, whether it be for patients with LBP or healthy individuals, may not be justified unless symptoms of spinal instability are identified.