The relationship between obesity, low back pain, and lumbar disc degeneration when genetics and the environment are considered: a systematic review of twin studies

BACKGROUND CONTEXT: The relationships between obesity and low back pain (LBP) and lumbar disc degeneration (LDD) remain unclear. It is possible that familial factors, including genetics and early environment, affect these relationships.PURPOSE: To investigate the relationship between obesity-related measures (eg, weight, body mass index [BMI]) and LBP and LDD using twin studies, where the effect of genetics and early environment can be controlled.STUDY DESIGN: A systematic review with meta-analysis.METHODS: MEDLINE, CINAHL, Scopus, Web of Science, and EMBASE databases were searched from the earliest records to August 2014. All cross-sectional and longitudinal observational twin studies identified by the search strategy were considered for inclusion. Two investigators independently assessed the eligibility, conducted the quality assessment, and extracted the data. Metaanalyses (fixed or random effects, as appropriate) were used to pool studies'estimates of association.RESULTS: In total, 11 articles met the inclusion criteria. Five studies were included in the LBP analysis and seven in the LDD analysis. For the LBP analysis, pooling of the five studies showed that the risk of having LBP for individuals with the highest levels of BMI or weight was almost twice that of people with a lower BMI (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.6-2.0; I-2 = 0%). A dose-response relationship was also identified. When genetics and the effects of a shared early environment were adjusted for using a within-pair twin case-control analysis, pooling of three studies showed a reduced but statistically positive association between obesity and prevalence of LBP (OR 1.5; 95% CI 1.1-2.1; I-2 = 0%). However, the association was further diminished and not significant (OR 1.4; 95% CI 0.8-2.3; I-2 = 0%) when pooling included two studies on monozygotic twin pairs only. Seven studies met the inclusion criteria for LDD. When familial factors were not controlled for, body weight was positively associated with LDD in all five cross-sectional studies. Only two cross-sectional studies investigated the relationship between obesity-related measures and LDD accounting for familial factors, and the results were conflicting. One longitudinal study in LBP and three longitudinal studies in LDD found no increase in risk in obese individuals, whether or not familial factors were controlled for.CONCLUSIONS: Findings from this review suggest that genetics and early environment are possible mechanisms underlying the relationship between obesity and LBP; however, a direct causal link between these conditions appears to be weak. Further longitudinal studies using the twin design are needed to better understand the complex mechanisms underlying the associations between obesity, LBP, and LDD.

Electromyographic study of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a plain and on a tilt Roman table

The objective of this paper was to analyse the activity of the longissimus dorsi and the iliocostalis lumborum muscles--components of the erector spinae muscle--in order to determine: their action potentials during the use of a plain and a tilt Roman table; 2) to compare the action potentials of the two muscles; 3) to verify if the action potential of these two muscles remain constant during the arc of movement--knee flexion and extension--divided into angle ranges, and 4) to compare the action potentials of the muscles in movements performed in a free manner and against resistance. Twenty-three young volunteers were studied electromyographically and each muscle received a needle electrode (Mise) and a surface electrode. The results showed that the table model did not determine any difference in the action potential of the muscles and that, on average, the iliocostalis lumborum muscle developed a slightly higher action potential than the longissimus dorsi muscle during the free flexion of knees on the plain table. In more than 70% of the cases, there was no difference between the action potential of the muscles over the various angle ranges of knee flexion and extension. Relatively higher action potentials were recorded during knee flexion and extension against resistance than during the same movements performed in a free manner. This shows that the paravertebral musculature responds better to an overload (8 kg) imposed on the knee flexor group, confirming the stabilizing role of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a Roman table.

Morphological characteristics of neuromuscular junctions of the opossum (Didelphis albiventris) extraocular muscles: a scanning-electron-microscopic study

Three types of neuromuscular junctions were described in the extraocular muscles of the opossum. The present study demonstrates the three-dimensional characteristics of these neuromuscular junctions after HCl connective tissue digestion. Adult opossum of both sexes were used and the neuromuscular junctions of the extraocular muscles were examined after removal of the intramuscular connective tissue and basal layer. This material was examined with a scanning electron microscope. Two types of 'en plaque' neuromuscular junction were described: the continuous type revealed elongated and branched primary synaptic grooves separated from each other by sarcolemma protuberances with different sizes, and the discontinuous or punctiform type which presents very shallow and discontinuous grooves when compared with the former. The multiple neuromuscular junctions were observed as two or three junctions associated with the same muscular fiber. The multiple junctions were present in thin fibers (around 11 microm caliber); the en plaque junctions were associated with large diameter fibers (around 21 microm). This study confirms and reveals the detailed morphological characteristics of the three neuromuscular junction types previously described by transmission electron microscope in the extraocular muscles of opossum.

Electromyographic validation of the trapezius and serratus anterior muscles in military press exercises with open grip

It was studied the trapezius muscle and serratus anterior muscle in 24 male volunteers using a 2-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes, during the execution of four different modalities of military press exercises with open grip. The results showed that TS acted significantly in the modalities standing and sitting press behind neck, while SI acted in all the modalities, i.e., standing and sitting press behind neck and forward, justifying their inclusion as basic exercises for physical conditioning programmes.

Evaluation of silent period on masticatory cycles of different muscles in dentate oral contraceptives users and nonusers

The aim of this study was to evaluate the influence of oral contraceptive use on the silent period (SP) of anterior temporal and masseter muscles during the menstrual cycle. Totally, 28 women on reproductive age were selected including 15 nonusers of any hormone and 13 contraceptive users. All patients were dentate without muscular temporomandibular disorders. Electromyography (SP test) of the anterior temporal and masseter muscles was conducted every week during three consecutive menstrual cycles at 1(st) day of menstruation (P1), 7(th) day (P2), 14(th) day (P3) and 21(st) day (P4). The SP values in the anterior temporal and masseter muscles were measured at both sides. The SP values of the right side (13.49 ms) at P2 were significantly different compared to the left side (12.28 ms). However, there was no significant difference on the interactions among the three factors. It can be concluded that the SP values in healthy women in reproductive age may not be influenced by the menstrual cycle with similar results for both muscles.

Effects of neuromuscular electrical stimulation on the masticatory muscles and physiologic sleep variables in adults with cerebral palsy: a novel therapeutic approach

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Neuromuscular efficiency of the vastus lateralis and biceps femoris muscles in individuals with anterior cruciate ligament injuries

To analyze strength and integrated electromyography (IEMG) data in order to determine the neuromuscular efficiency (NME) of the vastus lateralis (VL) and biceps femoris (BF) muscles in patients with anterior cruciate ligament (ACL) injuries, during the preoperative and postoperative periods; and to compare the injured limb at these two times, using the non-operated limb as a control. EMG data and BF and VL strength data were collected during three maximum isometric contractions in knee flexion and extension movements. The assessment protocol was applied before the operation and two months after the operation, and the NME of the BF and VL muscles was obtained. There was no difference in the NME of the VL muscle from before to after the operation. On the other hand, the NME of the BF in the non-operated limb was found to have increased, two months after the surgery. The NME provides a good estimate of muscle function because it is directly related to muscle strength and capacity for activation. However, the results indicated that two months after the ACL reconstruction procedure, at the time when loading in the open kinetic chain within rehabilitation protocols is usually started, the neuromuscular efficiency of the VL and BF had still not been reestablished.

Downhill running excessive training inhibits hypertrophy in mice skeletal muscles with different fiber type composition

The aim of this study was to verify the effects of running overtraining protocols performed in downhill, uphill, and without inclination on the proteins related to hypertrophy signaling pathway in extensor digitorum longus (EDL) and soleus of C57BL/6 mice. We also performed histological and stereological analyses. Rodents were divided into control (CT; sedentary mice), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up), and overtrained by running without inclination (OTR). The incremental load, exhaustive, and grip force tests were used as performance evaluation parameters. 36 h after the grip force test, EDL and soleus were removed and immediately used for immunoblotting analysis or stored at -80°C for histological and stereological analyses. For EDL, OTR/down decreased the protein kinase B (Akt) and tuberous sclerosis protein 2 (TSC2) phosphorylation (p), and increased myostatin, receptor-activated Smads (pSMAD2-3), and insulin receptor substrate-1 (pIRS-1; Ser307/636). OTR/down also presented low and high relative proportions of cytoplasm and connective tissue, respectively. OTR/up increased the mammalian target of rapamycin (pmTOR), 70-kDa ribosomal protein S6 kinase 1 (pS6K1) and pSMAD2-3, and decreased pTSC2. OTR decreased pTSC2 and increased pIRS-1 (Ser636). For soleus, OTR/down increased S6 ribosomal protein (pS6RP) and pSMAD2-3, and decreased pIRS-1 (Ser639). OTR/up decreased pS6K1, pS6RP and pIRS-1 (Ser639), and increased pTSC2 (Ser939), and pSMAD2-3. OTR increased pS6RP, 4E-binding protein-1 (p4E-BP1), pTSC2 (Ser939), and pSMAD2-3, and decreased pIRS-1 (Ser639). In summary, OTR/down inhibited the skeletal muscle hypertrophy with concomitant signs of atrophy in EDL. The effects of OTR/up and OTR depended on the analyzed skeletal muscle type. J. Cell. Physiol. 9999: 1-12, 2015. © 2015 Wiley Periodicals, Inc.

Análise da rotação ombro-quadril e co-contração muscular do tronco durante um movimento de rotação axial com manuseio de carga

Pós-graduação em Engenharia Mecânica - FEG

Back-to-back correlations in finite expanding systems

Back-to-Back Correlations (BBC) of particle-antiparticle pairs are predicted to appear if hot and dense hadronic matter is formed in high energy nucleus-nucleus collisions. The BBC are related to in-medium mass-modification and squeezing of the quanta involved. Although the suppression of finite emission times were already known, the effects of finite system sizes and of collective phenomena had not been studied yet. Thus, for testing the survival and magnitude of the effect in more realistic situations, we study the BBC when mass-modification occurs in a finite sized, thermalized medium, considering a non-relativistically expanding fireball with finite emission time, and evaluating the width of the back-to-back correlation function. We show that the BBC signal indeed survives the expansion and flow effects, with sufficient magnitude to be observed at RHIC.

Relação entre testes clínicos e desfechos de dor e incapacidade de pacientes com dor lombar crônica não específica submetidos ao programa de controle motor

Pós-graduação em Fisioterapia - FCT

Início de ativação muscular de estabilizadores primários e a capacidade física para avaliar estabilização lombo-pélvica

Introduction: Due to the high incidence of low back pain without apparent cause, different approaches to evaluate the lumbar instability has been proposed, such as surface electromyography to determine pre-activation and the ability of lumbar stabilization through functional physical assessment. In this context, the objective of this study was to evaluate the early activation of the primary stabilizing muscles in subjects without low back pain, with different physical abilities function (CFF). Method: Study participants were 20 subjects with 19.8 ± 1.4 years, 55.7 ± 8.8 kilos, 1.66 ± 0.08 m, of both sexes. The subjects underwent six Tests Physical Function (TFF) and the Test of Fast Moving Flexion Arm (TMRFB) to capture the electromyographic activity of the lumbar multifidus muscles (LM) and internal oblique - lower fibers (HI). Were assigned weights for each functional test and the result of the physical capacity of the final functional subject ranged from 0 to 100%. In the analysis of TMRB was considered the onset time of activation between the ML and HI. Results: Regarding TFF 2 (10%) subjects were considered to have normal physical capacity, 6 (30%) with good physical ability and 12 (60%) with regular physical capacity or poor. As for TMRFB average values of initiation of muscle activation in 75% of subjects were within the limits to characterize the condition of pre-muscle activation. Conclusion:The results obtained in the TFF were low compared with the CFF of asymptomatic subjects evaluated. This fact does not mean that the condition of stabilization of the subject is appropriate. However, the results obtained in the electromyographic examination to suggest that 25% of asymptomatic subjects tested did not have a proper condition of lumbar stabilization.

Rural Nebraska: Looking Back at a Decade of Change and Progress: 2005 Nebraska Rural Poll Results

To commemorate the 10th anniversary of the Nebraska Rural Poll, rural Nebraskans were asked about changes they may have experienced during the past ten years. Where have they lived during the past decade? In what types of business activities have they been involved? Have they received any education or training during that time period? What has been their experience with the Internet? This report details 2,851 responses to the 2005 Nebraska Rural Poll, the tenth annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions about changes they have experienced during the past ten years. For all questions, comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged: One quarter of rural Nebraskans have lived somewhere other than their current community during the past ten years. Of those who have lived elsewhere, they have moved their primary residence an average of 2.2 times. Younger rural Nebraskans are more likely than older residents to have lived elsewhere during the past decade. Sixty-six percent of persons between the ages of 19 and 29 have lived in a different location, compared to only 12 percent of persons age 65 and older. Many rural Nebraskans who have lived in a different community during the past ten years have lived in another state. Forty-one percent of persons who have lived elsewhere during the past decade have lived in a different state. Forty-five percent have lived in a larger community (18% have lived in either Omaha or Lincoln and 27% have lived in or near a Nebraska community larger than their current one - other than Lincoln or Omaha). Thirty-six percent have lived in or near a Nebraska community smaller than their current one. Twenty percent of rural Nebraskans currently own a business. Thirteen percent started operating a business during the past ten years, 10 percent closed or stopped operating a business during this time period and four percent tried unsuccessfully to start a business. Persons living in or near the smallest communities are more likely than persons living in or near larger communities to currently own a business. Twenty-nine percent of persons living in or near communities with less than 500 people currently own a business, compared to 15 percent of persons living in or near communities with at least 10,000 persons. In general, rural Nebraskans have favorable opinions about self-employment but they also recognize the hardships and risks involved with this type of employment. Sixtyone percent agree that self-employment is desirable because they can be their own boss. Forty-four percent agree that self-employment provides a better quality of life than being an employee. However, 74 percent agree that self-employed individuals work longer hours than traditional employees and 70 percent agree that the cost of health insurance makes self-employment unappealing. Younger persons are more likely than older persons to agree that the cost of health insurance makes self-employment unappealing. Eighty percent of persons age 19 to 29 agree with that statement, compared to 55 percent of persons age 65 and older. One-half of rural Nebraskans have participated in formal education courses, workshops or other training activities during the past ten years. Sixty-nine percent of rural Nebraskans have Internet access either at home or at work. Sixty-six percent have acquired Internet access either at home or at work during the past ten years. An additional three percent had acquired access more than ten years ago. Persons with higher levels of income are more likely than persons with lower incomes to have acquired Internet access. Sixty-six percent of persons with household incomes of $60,000 or more have acquired Internet access at both home and work during the past ten years, compared to only 11 percent of persons with household incomes less than $20,000. Information searches and email are the most important reasons for having an Internet connection. Eighty-nine percent of rural Nebraskans with access to the Internet at either home or work say that information searches are an important or very important reason for having an Internet connection. Eighty-three percent say email is an important reason. In general, rural Nebraskans say their satisfaction with various features of their Internet connection has increased during the past ten years. Fifty-five percent of rural Nebraskans with an Internet connection at home say their satisfaction with the availability of service has increased during the past ten years and 50 percent report an increase in their satisfaction with the speed of their connection. Persons living in or near the larger communities are more likely than persons living in or near the smaller communities to say their satisfaction with the speed of their Internet connection has increased during the past ten years. Fifty-four percent of persons living in or near communities with populations of 5,000 or more say their satisfaction with the speed of their connection has increased over the past decade, compared to 43 percent of persons living in or near communities with less than 1,000 people.

Morphology of the Gas Bladder in Bumblebee Catfishes (Siluriformes, Pseudopimelodidae)

The gross morphology of the gas bladder is described and compared for representatives of all valid genera of Pseudopimelodidae (Siluriformes). Cephalosilurus albomarginatus and species of Batrochoglanis, and Microglanis have the most basic form: a large, cordiform gas bladder with a simple internal T-shaped septum. Cephalosilurus apurensis, C. fowleri, and C. nigricauda also have a large, cordiform gas bladder, but they have well-developed trabeculae associated with the internal T-shaped septum, and a pair of well-developed constrictor muscles inserted on the external wall; the latter feature is present in most species of Pimelodidae, but absent in all other catfishes. The monotypic Lophiosilurus alexandri also has well-developed constrictor muscles, and its gas bladder is moderately sized. The species of Pseudopimelodus and Cruciglanis have a diminutive gas bladder partially divided into two lateral sacs without internal communication, and lack constrictor muscles. The parapophysis of the fourth vertebra is a wide and long shelf connected to the dorsal surface of the gas bladder in most pseudopimelodid genera. However, in the species of Pseudopimelodus and Cruciglanis the parapophysis of the fourth vertebra is shorter and has its anterior ramus folded back, partially covering the gas bladder anteroventrally; and the tympanic opening is smaller than in species of the other genera. Five phylogenetic characters are proposed based on the morphology of the gas bladder and associated structures in species of Pseudopimelodidae, and the evolution of those characters in the family is discussed. J. Morphol. 272:890-896, 2011. (C) 2011 Wiley-Liss, Inc.

Effect of the inclusion of fish residue oils in diets on the fatty acid profile of muscles of males and females lambari (Astyanax altiparanae)

This study evaluated the effects of two lipids sources of fish residue (tilapia and salmon) compared with a vegetable oil source (soybean oil) on the fatty acid profiles of male and female lambari. This experiment was developed in a completely randomized experimental design in a 3 x 2 factorial arrangement, totaling 6 treatments resulting from the combination of the three experimental diets for both sexes, with four replications for each treatment. This study involved 120 male (2.58 +/- 0.13 g) and 72 female lambari (4.00 +/- 0.09 g), fed the experimental diets twice a day until apparent satiation for a period of 60 days. Oleic, linoleic, palmitic and stearic fatty acids were found at higher concentrations in all experimental oils and diets, as well in the muscle of male and female lambari. The low amounts of arachidonic, eicosapentaenoic and docosahexaenoic acids in the experimental diets and subsequent greater concentrations in muscle tissue, suggested that lambari are able to desaturate and elongate the chain of fatty acids with 18 carbons. The fish of both sexes that received the diet with soybean oil showed high levels of n-6 fatty acids, especially of C18: 2n-6 and low levels of eicosapentaenoic and docosahexaenoic acids. The diet with salmon residue oil promoted higher levels of fatty acids of the n-3 series and resulted in the best n-3/n-6 ratio in the muscle of male and female lambari. The oils from fish residues can be a substitute for traditional fish oil and its use in the lambari diets does not impair its growth.