Correction to: Feasibility study: one year fortnightly follow-up of the evolution of supra-spinatus degeneration via text-messages.

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Feasibility study: one year fortnightly follow-up of the evolution of supra-spinatus degeneration via text-messages.

BACKGROUND: The clinical follow-up of patients for degeneration of the supraspinatus tendon is limited by the lack of objective assessment of pain evolution over time. We therefore tested a new method to collect follow-up data on patients treated either by surgical cuff repair or rehabilitation. OBJECTIVES: We report the feasibility this method in terms of recruitment of clinicians and patients and their compliance. METHODS: In this multicenter longitudinal observational study, between September 2015 and March 2019, patients consulting either for surgical repair or rehabilitation were examined at baseline and after twelve months by their clinician, including the Mini-DASH questionnaire. Fortnightlys, during one year, patients were asked about number of days their shoulder problem affected their daily life, number of nights woken up from shoulder pain, and present pain score, using text-messages for sending and responding to questions. A system administrator supervised responses and non-compliant subjects were contacted and assisted with the procedure. The CONSORT statement for pilot studies was followed. RESULTS: Four of 11 invited clinicians accepted participation and collected data till the end. Of the 410 patients we originally planned for, 252 were included in the study, but complete data for the clinicians' follow-up at 12 months were missing for 30. Of the 222 subjects with SMS data files, 190 (85%) provided at least 80% of their fortnightly messages. All three SMS messages were answered equally often. In total, 160 study subjects answered at least 80% of times and had clinical data at twelve months, i.e. 39% of the intended study sample and 72% of the 222 subjects with SMS data. CONCLUSION: The most important difficulty of this study was the enrolment and compliance of clinicians. The collection of SMS data was less successful than in previous studies, but French people accepted well this new method which is much easier and specific than collecting data through clinical records. The quality of the SMS data was acceptable. However, because of the limited number of complete datasets, only a limited number of questions from the original study protocol can be answered.

What is the effect of spinal manipulation on the pressure pain threshold in young, asymptomatic subjects? A randomized placebo-controlled trial, with a cross-over design.

BACKGROUND: Spinal manipulation (SM) has been shown to have an effect on the pressure pain threshold (PPT) in asymptomatic subjects, but SM has never been compared in studies on this topic to a validated sham procedure. We investigated the effect of SM on the PPT when measured i) in the area of intervention and ii) in an area remote from the intervention. In addition, we measured the size and duration of the effect. METHOD: In a randomized cross-over trial, 50 asymptomatic chiropractic students had their PPT measured at baseline, immediately after and every 12 min after intervention, over a period of 45 min, comparing values after SM and a previously validated sham. The trial was conducted during two sessions, separated by 48 h. PPT was measured both regionally and remotely from the 'treated' thoracic segment. Blinding of study subjects was tested with a post-intervention questionnaire. We used mixed linear regression with the baseline value and time as co-variates. If a significant difference were found between groups, then an effect size would be calculated using Cohen's d or Hedge's h coefficient. Statistical significance was set at p < 0.05. RESULTS: Study subjects had been successfully blinded. No statistically significant differences were found between SM and sham estimates, at any time or anatomical location. CONCLUSION: When compared to a valid sham procedure and with successfully blinded subjects, there is no regional or remote effect of spinal manipulation of the thoracic spine on the pressure pain threshold in a young pain-free population.

The effect of a single spinal manipulation on cardiovascular autonomic activity and the relationship to pressure pain threshold: a randomized, cross-over, sham-controlled trial.

Background: The autonomic nervous system interacts with the pain system. Knowledge on the effects of high velocity low amplitude spinal manipulations (SM) on autonomic activity and experimentally induced pain is limited. In particular, the effects of SM on autonomic activity and pain beyond the immediate post intervention period as well as the relationship between these two outcomes are understudied. Thus, new research is needed to provide further insight on this issue. Objectives: The aim was to assess the effect of a single SM (i.e. SM vs. sham) on cardiovascular autonomic activity. Also, we assessed the relationship between cardiovascular autonomic activity and level of pain threshold after the interventions. Method: We conducted a randomized, cross-over, sham-controlled trial on healthy first-year chiropractic students comprising two experimental sessions separated by 48 h. During each session, subjects received, in a random order, either a thoracic SM or a sham manipulation. Cardiovascular autonomic activity was assessed using heart rate and systolic blood pressure variabilities. Pain sensitivity was assessed using pressure pain threshold. Measurements were performed at baseline and repeated three times (every 12 min) during the post intervention period. Participants and outcome assessors were blinded. The effect of the SM was tested with linear mixed models. The relationship between autonomic outcomes and pressure pain threshold was tested with bivariate correlations. Results: Fifty-one participants were included, forty-one were finally analyzed. We found no statistically significant difference between SM and sham in cardiovascular autonomic activity post intervention. Similarly, we found no post-intervention relationship between cardiovascular autonomic activity and pressure pain threshold. Conclusion: Our results suggest that a single SM of the thoracic spine has no specific effect on cardiovascular autonomic activity. Also, we found no relationship between cardiovascular autonomic activity and pressure pain threshold after the SM. Further experimental research should consider the use of several markers of autonomic activity and a more comprehensive pain assessment. Trial registration: N° NCT03273868. Registered September 6, 2017.

Contexte: Le système nerveux autonome interagit avec le système de la douleur. Les connaissances concernant les effets des manipulations vertébrales (MV) de haute vélocité et de faible amplitude sur l'activité autonome et la douleur induite expérimentalement sont limitées. En particulier, les effets des MV sur l'activité autonome et la douleur au-delà de la période située immédiatement après l'intervention sont sous-étudiés, tout comme la relation entre ces deux variables. De nouvelles études sont nécessaires pour mieux comprendre cette problématique. Objectifs: Le premier objectif était d'évaluer l'effet d'une MV (i.e. MV vs placébo) sur l'activité autonome cardiovasculaire. Le second objectif était d'évaluer la relation entre l'activité autonome cardiovasculaire et le seuil de douleur après les interventions. Méthode: Nous avons réalisé un essai randomisé, croisé, contrôlé par un placébo sur des sujets jeunes et en bonne santé (étudiants en première année de chiropraxie). L'étude comprenait deux sessions expérimentales séparées par 48 h. Les sujets recevaient durant chaque session, soit une MV thoracique, soit une manipulation placébo. L'activité autonome cardiovasculaire était évaluée en utilisant la variabilité de la fréquence cardiaque et la variabilité de la pression artérielle systolique. La sensibilité à la douleur était évaluée en utilisant le seuil de douleur à la pression. Les mesures étaient réalisées avant l'intervention et répétées trois fois après celle-ci (toutes les 12 min). Les participants et les collecteurs de données étaient en aveugle. L'effet de la MV était testé en utilisant des modèles linéaires mixtes. Nous avons testé la relation entre les variables autonomes et le seuil de douleur à la pression en utilisant des corrélations bivariées. Résultats: Cinquante-et-un sujets ont été inclus et quarante-et-un ont finalement été analysés. Nous n'avons pas trouvé de différence statistiquement significative entre la MV et le placébo en ce qui concerne l'activité autonome cardiovasculaire après l'intervention. Nous n'avons pas trouvé de relation post-intervention entre l'activité autonome cardiovasculaire et le seuil de douleur à la pression. Conclusion: Nos résultats suggèrent qu'une MV thoracique n'a pas d'effet spécifique sur l'activité autonome cardiovasculaire et qu'il n'y a pas de relation entre l'activité autonome et le seuil de douleur à la pression après la MV. On devrait considérer l'utilisation de plusieurs marqueurs de l'activité autonome ainsi qu'une évaluation plus complète de la douleur dans les recherches expérimentales futures.

How big is the effect of spinal manipulation on the pressure pain threshold and for how long does it last? - secondary analysis of data from a systematic review.

Background: Spinal manipulation (SM) has been shown in a systematic review to have a statistically significant effect on the pressure pain threshold (PPT) in asymptomatic subjects, when SM is compared to a sham intervention. The magnitude and duration of this effect is unclear. Objectives: To determine the effect-size of SM in asymptomatic subjects and its duration. Method: This is a secondary analysis of data from a previous review. We sought to compare the effect-sizes in the various articles but had to calculate them ourselves, at different follow-up time measurements. Effect-sizes (Cohen's d or Hedge's g coefficient) were considered low, medium, and large, at the cut points of 0.2, 0.5, and 0.8, respectively. Results: Effect-sizes were reported in 6/8 studies, but all had calculated 'within-group' changes, not 'between-group' differences. Immediately after SM, only one study of four (with four measurements) had a statistically significant 'medium' effect size (d = 0.56; 95% CI: 00.4-1.08 to d = 0.70; 95% CI:0.18-1.22). Five minutes after SM, 4/5 studies found a statistically significant 'medium to large' effect-size (d = 0.51; 95% CI: 0.04-0.98 to d = 1.24; 95% CI: 0.28-2.20). Ten minutes after SM, two studies reported a 'medium' effect-size with statistical significance (d = 0.58; 95% CI: 0.11-1.05 to d = 0.80; 95% CI: 0.12-1.48). We drew no conclusions for the effect-sizes at one minute and thirty minutes after SM, as no between-group statistical difference was found. Conclusion: Authors need to revise their approach to 'effect size'. Our calculations showed that the effect-size of SM on PPT may go from 'medium' to 'large' within the first five minutes but appears to diminish again within ten minutes. Research of this type should collect information for longer periods and compare results to other interventions to put results into perspective.

Contexte: Une revue systématique a montré que la manipulation vertébrale (MV) avait un effet statistiquement significatif sur le seuil de douleur à la pression (SDP) chez les sujets asymptomatiques, lorsque la MV était comparée à une manœuvre placébo. Cependant, l'ampleur et la durée de cet effet n'ont pas été clairement rapportées. Objectifs: Déterminer la taille d'effet de la MV chez les sujets asymptomatiques et sa durée. Méthode: Il s'agit d'une deuxième analyse des données de notre précédente revue systématique de la littérature. Nous avons cherché à comparer les tailles d'effet dans les différents articles, mais nous avons dû nous résoudre à les calculer, à différents temps de mesures. La taille d'effet rapportée (comme les coefficients d de Cohen ou g de Hedge) était considérée comme faible, moyenne et grande, aux seuils respectifs de 0,2, 0,5 et 0,8. Résultats: Nous avons constaté que 6 études sur 8 montraient le calcul de la taille d'effet, mais que toutes étaient fondées sur des changements « intra-groupe ¼, et non sur des différences « intergroupes ¼. Immédiatement après la MV, seule une étude sur quatre (avec quatre mesures) présentait une taille d'effet « moyenne ¼ statistiquement significative (d = 0,56 [IC à 95%: 00,4 à 1,08] à d = 0,70 [IC à 95%: 0,18 à 1,22]). Cinq minutes après la MV, quatre études sur cinq ont révélé une taille d'effet « moyenne à grande ¼ statistiquement significative (d = 0,51 [IC à 95%: 0,04­0,98] à d = 1,24 [IC à 95%: 0,28-2,20]). Dix minutes après la MV, deux études ont indiqué une taille d'effet « moyenne ¼ statistiquement significative (d = 0,58 [IC à 95%: 0,11-1,05] à d = 0,80 [IC à 95%: 0,12-1,48]). Aucune conclusion n'a été tirée des résultats une minute et trente minutes après la MV car la différence entre les groupes n'était pas statistiquement significative. Conclusion: Les auteurs doivent revoir leur approche de la « taille d'effet ¼. Nos calculs ont montré que l'effet de la manipulation vertébrale sur le seuil de la douleur à la pression peut passer de « moyen ¼ à « important ¼ dans les cinq premières minutes mais semble diminuer à nouveau dans les dix minutes. Les recherches de ce type devraient collecter des informations sur des périodes plus longues et comparer les résultats à ceux d'autres interventions afin de les mettre en perspective. Mots-clés: Taille d'effet; durée; manipulation vertébrale; seuil de douleur à la pression; sujets asymptomatiques.

The paraspinal muscle-tendon system: Its paradoxical anatomy.

Anatomy of the muscle-tendon system is an important component to musculoskeletal models. In particular, the cross-sectional area of belly (mCSA) and tendon (tCSA) provides information about the maximum force that a muscle may exert. The ratio of mCSA to tCSA (rCSA) demonstrates how muscle force is related to the ability to resist/transmit the force to bone. Previous anatomical studies of the lumbar paraspinal muscles (LPM) showed that their bellies have large mCSA suggesting that they are powerful muscles. Surprisingly, surgical experience shows that the tendons of the LPM are among the thinnest tendons of the body. We therefore hypothesized that traditional biomechanics of the LPM and the rCSA do not correspond for LPM. In 10 fresh-frozen old cadavers, we measured the mCSA, tCSA and rCSA of the LPM (multifidus and the erector spinae, i.e. the longissimus and the iliocostalis); then, we compared these data with those of one of the weakest muscles in the body, i.e. the extensor digitorum communis (EDC) chosen because it shares some common anatomical features with the LPM, in particular with the erector spinae. For instance, the EDC has a polyarticular course and presents long and thin effector tendons. Among the LPM, the longissimus has the greatest mean ACSA with 10.42 cm2 compared with 9.16 cm2 for the iliocostalis and 0.24 cm2 for the multifidus. Mean ACSA of the EDC was almost ten times smaller than those of erector spinae. Regarding the mean tCSA, the EDC was the largest one with 11.48 mm2 compared with 2.69 mm2 and 1.43 mm2 for the longissimus, 5.74 mm2 and 2.38 mm2for the iliocostalis and 5.28 mm2 and 4.96 mm2 for the multifidus. Mean rCSAs of the erector spinae were extremely small, ranged from 1/156 for the spinal attachment of the iliocostalis to 1/739 for the rib attachment of the longissimus that suggests that tendons are an unsuitable size to transmit the force to bone. Mean rCSA of the multifidus and the EDC were in the same range with rCSA = 1/5 and rCSA = 1/9 respectively. The rCSA of the multifidus was substantial, but its ACSA (1cm2) corresponds to low-power muscles. This paradoxical anatomy compels us to consider the biomechanics of the LPM in a different way from that of the classical "chord-like model", i.e. the muscle belly creates a force that is applied to a bone piece through a tendon. The LPM have large contractile mass in a semi-rigid compartment inside which the pressure may increase. This result strengthens the hypothesis that high pressure and intrinsic stiffness of the LPM create two stiff bodies, closely attached to the spine thus ensuring its stabilization.

Posture-related stiffness mapping of paraspinal muscles.

The paraspinal compartment acts as a bone-muscle composite beam of the spine. The elastic properties of the paraspinal muscles play a critical role in spine stabilization. These properties depend on the subjects' posture, and they may be drastically altered by low back pain. Supersonic shear wave elastography can be used to provide quantitative stiffness maps (elastograms), which characterize the elastic properties of the probed tissue. The aim of this study was to challenge shear wave elastography sensitivity to postural stiffness changes in healthy paraspinal muscles. The stiffness of the main paraspinal muscles (longissimus, iliocostalis, multifidus) was measured by shear wave elastography at the lumbosacral level (L3 and S1) for six static postures performed by volunteers. Passive postures (rest, passive flexion, passive extension) were performed in a first shear wave elastography session, and active postures (upright, bending forward, bending backward) with rest posture for reference were performed in a second session. Measurements were repeated three times for each posture. Sixteen healthy young adults were enrolled in the study. Non-parametric paired tests, multiple analyses of covariance, and intra-class correlations were implemented for analysis. Shear wave elastography showed good to excellent reliability, except in the multifidus at S1, during bending forward, and in the multifidus at L3, during bending backward. Yet, during bending forward, only poor quality was recorded for nine volunteers in the longissimus. Significant intra- and inter-muscular changes were observed with posture. Stiffness significantly increased for the upright position and bending forward with respect to the reference values recorded in passive postures. In conclusion, shear wave elastography allows reliable assessment of the stiffness of the paraspinal muscles except in the multifidus at S1 and longissimus, during bending forward, and in the multifidus at L3, during bending backward. It reveals a different biomechanical behaviour for the multifidus, the longissimus, and the iliocostalis.

The acute effects of joint manipulative techniques on markers of autonomic nervous system activity: a systematic review and meta-analysis of randomized sham-controlled trials.

Background: The autonomic nervous system (ANS) interests many chiropractors and manual therapists, because joint manipulative techniques (JMT), e.g. high velocity low amplitude (HVLA) manipulations and mobilizations, appear to produce acute changes in ANS mediated physiology. The complexity of this issue justifies a systematic critical literature review. Objective: To review the literature comparing the acute changes in markers of ANS activity between JMT applied on spinal or peripheral joints and a sham procedure in healthy or symptomatic subjects. Method: We searched PsycINFO, PEDro, PubMed, Cochrane library, EMBASE, and Medline up to December 2017. We updated the search with PubMed, Cochrane library, EMBASE, and Medline including July 2018. Inclusion criteria were: randomized sham-controlled trials assessing the effect of JMT on markers of ANS activity; manually applied JMT, regardless of technique, applied on either healthy or symptomatic humans; outcome measurements recorded at baseline and repeated during and/or after interventions. Selection of articles and data extraction were performed independently by two reviewers. The quality of studies was assessed using the Cochrane 'risk of bias' tool and a technical check-list. Results were reported narratively with some meta-analyses. The Cochrane GRADE approach was used to assess the certainty of evidence. Results: Twenty-nine of 2267 studies were included in the synthesis. Mobilizations (oscillatory technique) probably produce an immediate and short-term, bilateral increase in skin sympathetic nerve activity (reflected by an increase in skin conductance) regardless of the area treated (moderate-certainty evidence). It is uncertain whether the sympathetic arousal also explains an increase in respiratory rate (very low-certainty evidence). Our evaluation of the literature suggests that spinal sustained apophyseal glides (SNAGs) mobilization and HVLA manipulation of the spine may have no acute effect on the studied markers of ANS activity (very low- to low-certainty evidence). Conclusion: Some types of mobilizations probably produce an immediate and short-term, statistically significant increase in skin sympathetic nerve activity when compared to a sham procedure, whereas spinal SNAGs and spinal HVLA techniques may have no acute effect on the studied markers of ANS activity. No region-specific results were noted. The literature suffers from several shortcomings, for which reason we strongly suggest further research.

Introduction: Le système nerveux autonome (SNA) intéresse de nombreux chiropracteurs et thérapeutes manuels car les techniques de manipulation articulaire, e.g. mobilisations ou manipulations de haute vélocité et faible amplitude (HVLA) semblent produire des changements immédiats de l'activité du SNA. La complexité de la littérature sur le sujet justifie une revue critique de la littérature. Objectif: Examiner la littérature comparant les changements immédiats d'activité du SNA entre i) différentes techniques de manipulation articulaire appliquées sur le rachis ou les articulations périphériques et ii) une procédure placebo chez des sujets sains ou pathologiques. Méthode: Nous avons cherché sur PsycINFO, PEDro jusqu'en décembre 2017 et sur PubMed, Cochrane library, EMBASE, Medline jusqu'en juillet 2018. Les critères d'inclusion étaient: essais randomisés contrôlés par un placebo évaluant l'effet d'une technique de manipulation articulaire sur l'activité du SNA, sans restriction concernant la technique ou la population, mesures de l'activité du SNA réalisées avant, pendant et/ou après l'intervention. La qualité des études était évaluée avec la grille de risque de biais de Cochrane et avec une grille d'évaluation technique. La sélection des études et l'extraction des données étaient effectuées indépendamment par deux chercheurs. Les résultats ont été rapportés narrativement, parfois avec des méta-analyses, en évaluant la certitude du niveau de preuve avec l'approche GRADE de Cochrane. Résultats: Nous avons inclus 29 études sur les 2267 trouvées. Il y a des preuves de certitude modérée que les mobilisations (avec une technique d'oscillation) produisent une augmentation bilatérale, immédiate et à court terme de l'activité sympathique cutanée, indépendamment de la région mobilisée. Nous ne savons pas si l'excitation sympathique explique une augmentation de la fréquence respiratoire. Il y a des preuves de faible certitude que la manipulation spinale (HVLA) ainsi qu'une autre technique de mobilisation spinale n'ont pas d'effet sur l'activité autonome mesurée. Conclusion: Certaines techniques de mobilisation articulaire produisent probablement une augmentation (statistiquement significative) immédiate et à court terme de l'activité sympathique cutanée comparées à une procédure placebo. Les manipulations spinales (HVLA) pourraient ne pas avoir d'effet immédiat sur l'activité autonome étudiée. Nous n'avons pas remarqué d'effet spécifique en fonction de la zone du traitement. Cette littérature montre des lacunes. Pour cette raison, nous suggérons (vivement) de nouvelles études.

Short-term DHEA administration in recreational athletes: impact on food intake, segmental body composition and adipokines.

BACKGROUND: Dehydroepiandrosterone (DHEA) administration is potentially therapeutic because it has been shown to decrease fat mass and adipokines and improve eating and mood disturbances. However, its impact on these parameters has never been investigated in a young healthy population. This study therefore sought to determine whether short-term DHEA administration would alter food intake, segmental body composition, adipokine secretion and mood in young healthy male and female volunteers with regular sport practice. METHODS: Following a double-blind and randomized protocol, 20 young healthy recreational athletes (10 men and 10 women) received treatment with either oral placebo or DHEA (100 mg/day for 4 weeks). Body weight, segmental body composition and adipokines (i.e., leptin, adiponectin and resistin) were determined before and at the end of each treatment. In parallel, spontaneous food intake was assessed at the end of each treatment, and mood was assessed before and at the end of treatment with the positive and negative affect schedule (PANAS). RESULTS: Body weight and segmental body composition showed no significant change in the men or women. Similarly, no change in adipokine secretion was found after DHEA administration. Total food intake was not affected by DHEA in any subject, despite an increase in fat intake by male subjects under DHEA (P<0.05). Positive and negative affect were not altered. CONCLUSIONS: In conclusion, in contrast to pathological populations, a young healthy population of men and women was not significantly affected by short-term DHEA administration with regard to total food intake, segmental body composition, adipokines or mood.

Influence of thoracolumbar fascia stretching on lumbar back muscle stiffness: A supersonic shear wave elastography approach.

The lumbar paraspinal muscle compartment (PMC) is a stabilizing system of the spine whose efficiency depends on its elastic properties, which may be quantifiable by supersonic shear wave elastography (SWE). The thoracolumbar fascia (TLF) encapsulates the lumbar paraspinal muscles (LPM) and creates a PMC. Tensioning of the TLF via the stretching of the latissimus dorsi is supposed to increase stiffness within the PMC. The aims of this study were (1) to test the reliability of SWE in the multifidus and the erector spinae (ES) in prone and sited position; (2) to investigate the role of the tensioning of the pTLF, via stretching of the latissimus dorsi (LD), on LPM stiffness. Stiffness of ES and multifidus was measured using SWE at L3-L4 in procubitus and seated position in 15 participants. Stretching of LD was performed with arm elevation. Parametric paired tests, multiple analyses of variance, and intraclass correlation were used for statistical analysis. Reliability estimates were fair to excellent. Reliability was greater in ES than the multifidus, greater in seated position than during rest. Stiffness was greater in the ES than in multifidus, and in seated position than at rest. Tensioning of the TLF via LD stretching did not generate significant LPM stiffness changes. SWE is a reliable tool for assessing stiffness in the LPM. Reliability of SWE protocols is improved during seated position. Tensioning of the TLF via LD stretching did not influence LPM stiffness. Clin. Anat. 32:73-80, 2019. © 2018 Wiley Periodicals, Inc.

Organization of the fascia and aponeurosis in the lumbar paraspinal compartment.

PURPOSE: The thoracolumbar fascia (TLF) and the erector spinae aponeurosis (ESA) play significant roles in the biomechanics of the spine and could be a source of low back pain. Attachment, collagen fiber direction, size and biomechanical properties of the TLF have been well documented. However, questions remain about the attachment of the TLF and ESA in relation to adjoining tissues in the lumbosacral region. Moreover, quantitative data in relation to the ESA have rarely been examined. The aim of this study was to further investigate the anatomical features of the TLF and ESA and to determine the attachments and sliding areas of the paraspinal compartment through dissection. MATERIALS AND METHODS: In 10 fresh cadavers (6 females, 4 males, mean age: 77 ± 10 years), we determined (1) the gross anatomy of the ESA and the TLF (attachments and sliding areas) and (2) the structure of the ESA and the TLF (thickness, width, orientation of collagen fibers). The pennation angle between the axis of the ES muscle fibers and the axis of the collagen fibers of the ESA were also measured. RESULTS: The TLF is an irregular dense connective tissue with a mean thickness of 0.95 mm. The distance between the spinous processes line and the site where the neurovascular bundles pierced the TLF, depending on the vertebral level, ranged from 29 mm at L1 to 75 mm at L3. The ESA constituted a band of regular longitudinally oriented connective fibers (mean thickness: 1.85 mm). Muscles fibers of the ES were strongly diagonally attached to the ESA (mean pennation angle 8° for the iliocostalis and 14° for the longissimus). To a lesser extent, the superficial multifidi were attached to the ESA at the lumbar level close to the midline and at the sacral level. CONCLUSION: The ESA, at twice the thickness of the pTLF, was the thickest dense connective tissue of the paraspinal compartment. The ESA and the TLF circumscribed subcompartments and sliding areas between the TFL and the lumbar paraspinal muscles, between the ES and the multifidus, and between the longissimus and the iliocostalis.

Short-term Dehydroepiandrosterone Intake and Supramaximal Exercise in Young Recreationally-trained Women.

WADA has banned dehydroepiandrosterone (DHEA) but its ergogenic effect in female athletes has never been investigated. The aim of this study was to determine whether short-term DHEA intake would improve performance during a supramaximal field exercise in healthy young recreationally trained women. Its impact on body composition, metabolic responses was also measured. Eleven young female volunteers completed four running-based anaerobic sprint tests: just before and after treatment with either oral placebo or DHEA (100 mg/day/28days), following a double-blind and randomized protocol. Bioelectrical impedance assessed body composition. At rest and after passive recovery, blood samples were collected for lactate measurement and saliva samples for DHEA, testosterone and cortisol analysis. There was no significant difference in body composition or performance parameters after DHEA administration, despite a tendency toward increased peak power and decreased fat mass. However, DHEA treatment induced a very marked increase in saliva DHEA and testosterone concentrations (p<0.001), with no change in cortisol or lactate levels. In conclusion, short-term DHEA administration did not improve performance or have an anabolic effect in young female recreationally trained athletes, despite the increase in androgenic hormones. Further studies are needed to determine whether a higher daily dose would generate an ergogenic effect during anaerobic exercise.

The regional effect of spinal manipulation on the pressure pain threshold in asymptomatic subjects: a systematic literature review.

Background: Spinal manipulation (SM) has been shown to have an effect on pain perception. More knowledge is needed on this phenomenon and it would be relevant to study its effect in asymptomatic subjects. Objectives: To compare regional effect of SM on pressure pain threshold (PPT) vs. sham, inactive control, mobilisation, another SM, and some type of physical therapy. In addition, we reported the results for the three different spinal regions. Method: A systematic search of literature was done using PubMed, Embase and Cochrane. Search terms were ((spinal manipulation) AND (experimental pain)); ((spinal manipulative therapy OR spinal manipulation) AND ((experimental pain OR quantitative sensory testing OR pressure pain threshold OR pain threshold)) (Final search: June 13th 2017). The inclusion criteria were SM performed anywhere in the spine; the use of PPT, PPT tested in an asymptomatic region and on the same day as the SM. Studies had to be experimental with at least one external or internal control group. Studies on only spinal motion or tenderness, other reviews, case reports, and less than 15 invited participants in each group were excluded. Evidence tables were constructed with information relevant to each research question and by spinal region. Results were reported in relation to statistical significance and were interpreted taking into account their quality. Results: Only 12 articles of 946 were accepted. The quality of studies was generally good. In 8 sham controlled studies, a psychologically and physiologically "credible" sham was found in only 2 studies. A significant difference was noted between SM vs. Sham, and between SM and an inactive control. No significant difference in PPT was found between SM and another SM, mobilisation or some type of physical therapy. The cervical region more often obtained significant findings as compared to studies in the thoracic or lumbar regions. Conclusion: SM has an effect regionally on pressure pain threshold in asymptomatic subjects. The clinical significance of this must be quantified. More knowledge is needed in relation to the comparison of different spinal regions and different types of interventions.

But: Un effet de la manipulation vertébrale a été observé sur la perception de la douleur. Plus de connaissances sont nécessaires sur ce phénomène et il serait pertinent d'étudier cet effet sur les sujets asymptomatiques. Objectifs: Evaluer l'effet régional de la MV sur le seuil de douleur à la pression (SDP) comparé à un placébo, un groupe contrôle, la mobilisation, une autre MV, et un autre type de physiothérapie. De plus, nous avons rapporté les résultats pour les régions cervicale, dorsale et lombaire. Méthode: La revue systématique de la littérature a été faite en utilisant PubMed, Embase et Cochrane. Les termes de recherche étaient ((manipulation vertébrale) ET (douleur expérimentale)); ((thérapie manuelle spinale OU manipulation spinale) ET (douleur expérimentale OU test quantitatif sensoriel OU seuil de douleur à la pression OU seuil de douleur)). (La recherche finale date du 13 juin 2017). Les critères d'inclusion étaient MV exécutées à n'importe quel niveau de la colonne vertébrale; l'utilisation du SDP, testé dans une région asymptomatique et le même jour que la MV. Les études devaient être expérimentales avec au moins un groupe externe à la MV ou un groupe contrôle interne. Les études uniquement sur le mouvement de la colonne vertébrale, tensions des tissus paravertébraux, les autres revues, les études de cas et des études avec moins de 15 participants dans chaque groupe ont été exclus. Des tables d'évidence ont été construites avec les informations appropriées à chaque question de recherche et reportées par régions. Les résultats ont été rapportés avec leur signification statistique et ont été interprétés en tenant compte de leur qualité. Résultats: Seulement 12 articles sur 946 ont été acceptés. La qualité des études est. en général bonne. Sur les 8 études contrôlées par placébo, un placébo psychologiquement et physiologiquement « crédible ¼ a été trouvé seulement dans 2 études. Une différence significative a été notée entre MV et le placébo, et entre MV et contrôle inactif. Aucune différence significative dans SDP n'a été trouvée entre MV et une mobilisation, une autre MV, ou un autre type de physiothérapie. Des résultats significatifs ont été trouvés plus souvent dans la région cervicale comparé aux études aux niveaux thoraciques et lombaires. Conclusion: La manipulation vertébrale a un effet régional sur le seuil de la douleur à la pression chez des sujets asymptomatiques. Sa différence clinique doit être quantifiée. Plus de connaissance est. nécessaire à propos de la comparaison des différentes régions spinales et différents types d'interventions.

Magnetic resonance elastography of the lumbar back muscles: A preliminary study.

Back pain is associated with increased lumbar paraspinal muscle (LPM) stiffness identified by manual palpation and strain elastography. Recently, magnetic resonance elastography (MRE) has allowed the stiffness of muscle to be characterized noninvasively in vivo, providing quantitative 3D stiffness maps (elastograms). The aim of this study was to characterize the stiffness (shear modulus, SM) of the LPM (multifidus and erector spinae) using MRE. MRE of the lumbar region was performed on seven adults in supine position. MRE was acquired in three muscular states: relaxed with outstretched legs, stretched with passive pelvis flexion, and contracted with outstretched legs and tightened trunk muscles. The mean SM was measured within a region of interest manually defined in the multifidus, erector spinae, and the entire paraspinal compartment. The intermuscular difference and the effects of stretching and contraction were assessed by ANOVA and t-tests. At rest, the mean SM of the paraspinal compartment was 1.6 ± 0.2 kPa. It increased significantly with stretching to 1.65 ± 0.3 kPa, and with contraction to 2.0 ± 0.7 kPa. Irrespective of muscular state, the erector spinae was significantly stiffer than the multifidus. The multifidus underwent proportionally higher stiffness changes from rest to contraction and stretching. MRE can be used to measure the stiffness of the LPM in different muscular states. We hypothesize that, irrespective of posture, the erector spinae behaves as semi-rigid beam, and ensures permanent stiffness of the spine. The multifidus behaves as an adaptable muscle that provides segmental flexibility to the spine and tunes the spine stiffness. Clin. Anat. 31:514-520, 2018. © 2018 Wiley Periodicals, Inc.

Effects of short-term DHEA intake on hormonal responses in young recreationally trained athletes: modulation by gender.

BACKGROUND: Dehydroepiandrosterone (DHEA) figures on the World Anti-Doping Agency list of prohibited substances in sport because it is assumed that athletes expect a significant increase in testosterone through DHEA administration. The literature on the hormonal effects of DHEA intake nevertheless appears to be very scant in healthy young subjects, especially women. PURPOSE: We examined the effects of DHEA on adrenal and gonadal hormones, IGF1 and free T3 in healthy young male and female recreationally trained volunteers. METHODS: The study followed a double-blind, randomized-order crossover design. Lean healthy young men (n = 10) and women (n = 11), with all women using oral contraceptives, were treated daily with 100 mg of DHEA and placebo for 4 weeks. DHEA, DHEA-sulfate (DHEA-S), androstenedione, total testosterone (Tes), dihydrotestosterone (DHT), SHBG, estrone, cortisol, IGF1, and free T3 were measured before, in the middle and at the end of each treatment, as were blood glucose, liver transaminases and lipid status. RESULTS: We observed a significant increase in DHEA, DHEA-S, androstenedione, Tes, DHT, and estrone in both men and women in the middle and at the end of DHEA treatment, but the increase in Tes was more marked in women (p < 0.001) than men (p < 0.05). No changes were found in the other parameters, irrespective of gender. CONCLUSION: In young athletes, DHEA administration induces significant blood hormonal changes, some modulated by gender, which can be used as biomarkers of doping.

Rigid Ankle Foot Orthosis Deteriorates Mediolateral Balance Control and Vertical Braking during Gait Initiation.

Rigid ankle-foot orthoses (AFO) are commonly used for impeding foot drop during the swing phase of gait. They also reduce pain and improve gait kinematics in patients with weakness or loss of integrity of ankle-foot complex structures due to various pathological conditions. However, this comes at the price of constraining ankle joint mobility, which might affect propulsive force generation and balance control. The present study examined the effects of wearing an AFO on biomechanical variables and electromyographic activity of tibialis anterior (TA) and soleus muscles during gait initiation (GI). Nineteen healthy adults participated in the study. They initiated gait at a self-paced speed with no ankle constraint as well as wearing an AFO on the stance leg, or bilaterally. Constraining the stance leg ankle decreased TA activity ipsilaterally during the anticipatory postural adjustment (APA) of GI, and ipsilateral soleus activity during step execution. In the sagittal plane, the decrease in the stance leg TA activity reduced the backward displacement of the center of pressure (CoP) resulting in a reduction of the forward velocity of the center of mass (CoM) measured at foot contact (FC). In the frontal plane, wearing the AFO reduced the displacement of the CoP in the direction of the swing leg during the APA phase. The mediolateral velocity of the CoM increased during single-stance prompting a larger step width to recover balance. During step execution, the CoM vertical downward velocity is normally reduced in order to lessen the impact of the swing leg with the floor and facilitates the rise of the CoM that occurs during the subsequent double-support phase. The reduction in stance leg soleus activity caused by constraining the ankle weakened the vertical braking of the CoM during step execution. This caused the absolute instantaneous vertical velocity of the CoM at FC to be greater in the constrained conditions with respect to the control condition. From a rehabilitation perspective, passively- or actively-powered assistive AFOs could correct for the reduction in muscle activity and enhance balance control during GI of patients.

Feasibility assessment of shear wave elastography to lumbar back muscles: A Radioanatomic Study.

Low back pain is often associated with tensional changes in the paraspinal muscles detected by palpatory procedures. Shear wave elastography (SWE), recently introduced, allows the stiffness of muscles to be assessed noninvasively. The aim of this work was to study the feasibility of using SWE on the three main lumbar back muscles (multifidus, longissimus, and iliocostalis) in vivo after analyzing their muscular architecture ex vivo. We determined the orientation of fibers in the multifidus, longissimus, and iliocotalis muscles in seven fresh cadavers using gross anatomy and B-Mode ultrasound imaging. We then quantified the stiffness of these three muscles at the L3 level ex vivo and in 16 healthy young adults. Little pennation was observed in the longissimus and iliocostalis, in which the direction of fibers was almost parallel to the line of spinous processes. The multifidus appeared as a multiceps and multipennate muscle. Given the random layering of millimetric fascicles, tendons, and fatty spaces, the multifidus had multiple fiber orientations. Muscular fascicles and fibers were oriented from 9° to 22° to the line of spinous processes. The shear moduli related to stiffness were 6.9 ± 2.7 kPa for the longissimus, 4.9 ± 1.4 kPa for the iliocostalis, and 5.4 ± 1.6 kPa for the multifidus. SWE is a feasible method for quantifying the stiffness of the lumbar back muscles. Clin. Anat. 30:774-780, 2017. © 2017Wiley Periodicals, Inc.

Mechanical strains passing through the acetabular labrum modify its shape during hip motion: an anatomical study.

PURPOSE: The function of the hip labrum during hip motion remains poorly known. Our hypothesis was that acetabular labrum will deform and change its shape during adduction to abduction movement consecutively to variation of strains passing from the acetabulum to the femoral head. An ex vivo anatomical study was conducted to analyse the morphological parameters variation of the mid-portion of the labrum (length, thickness, shape, deformation) as well as femoro-labral strains during hip adduction to abduction movement. METHODS: Ten fresh-frozen, unpaired human cadaver hemi-pelvises were obtained. To best approximate the clinical reality, fresh-frozen cadaver tissues were utilized. The hemi-pelvises were split sagittally in two equal parts through a plane crossing the femoral neck and femoral head centres. The hemi-pelvises were rigidly mounted on a test platform using a custom-made fixture, and a seven hundred Newton load was applied through the iliac wing, with a unidirectional movement (adduction/abduction) of the acetabulum above the fixed femur. Variations of strain passing from the labrum to the femoral head or neck were analysed using captors fixed on the acetabular edge. RESULTS: From 20° to 40° of abduction labral length decreased from a median of 5.8 (5.5-6.4 mm) to 4.6 (4-5.4 mm), labral edge angle increased from a median of 33.1 (31.1°-40°) to 52.3 (41.4°-58.8°), labral sectional area decreased from a median of 22.1 (17-27.1 mm2) to 14.2 (12-16.8 mm2) all p = 0.001. Femoro-labral strains were maximal at 40° of abduction [median 0.1 N mm-2 (0.1-3.1 N mm-2)] and minimal at 30° adduction (median 0 N mm-2 (0-0.1 N mm-2) and p = 0.001). CONCLUSION: The morphological variations of the mid-portion of the labrum during hip motion reflect strains passing from the labrum to the femoral head. Those elements may provide clues to understand the mechanical role of the labrum during abduction. The acetabular labrum bears a direct mechanical role during hip motion, thus resecting the hip's labrum during surgery might be detrimental for hip joint's biomechanics as it might modify strains distribution between the acetabulum and femur.

Are degenerative rotator cuff disorders a cause of shoulder pain? Comparison of prevalence of degenerative rotator cuff disease to prevalence of nontraumatic shoulder pain through three systematic and critical reviews.

HYPOTHESIS AND BACKGROUND: The role of degeneration is not well understood for rotator cuff pain. If age-related degenerative changes would be the cause of symptoms, degeneration would precede or concur with self-reported pain. We performed 3 systematic literature reviews. Our objectives were to determine the prevalence estimates for rotator cuff partial or complete tears (1) in cadavers and (2) in the general population and (3) to estimate the incidence/prevalence of self-reported nontraumatic shoulder pain in the general population in order to compare their respective age-related profiles. METHODS: We searched PubMed and ScienceDirect, including 2015, for cadaveric studies and transverse and longitudinal studies of the general population reporting the incidence/prevalence of rotator cuff disorders or nontraumatic shoulder pain, or both, according to age. The review process followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results were interpreted visually. RESULTS: We found 6 cadaveric studies, 2 studies from the general population reporting complete tears, and 10 articles on nontraumatic shoulder pain in the general population that met our criteria. The profiles of degeneration vs. pain were very similar in early years. Although degenerative rotators cuff lesions increased gradually after 50 years, the incidence/prevalence of nontraumatic shoulder pain decreased after 65 years. CONCLUSION: The profile of age-related degenerative rotator cuff disorders fails to correlate systematically with self-reported nontraumatic shoulder pain, particularly in older age; thus, it appears that degeneration should not be considered the primary source of the pain. Physical activity may play an important role in the production of the pain, a theory that warrants further study.

3D scapular orientation on healthy and pathologic subjects using stereoradiographs during arm elevation.

BACKGROUND: Alterations of the scapular kinematics in different pathologic conditions have been widely studied. However, results have shown considerable discrepancies concerning the direction and the amplitude of scapular movement. The lack of consistency in the literature probably has several explanations. The purpose of this study was to analyze scapular orientation with the arm at rest and with 90° lateral elevation in healthy and pathologic subjects by use of stereoradiographs. MATERIALS AND METHODS: All participants (n = 65) underwent a clinical examination and magnetic resonance imaging of the shoulder to assess rotator cuff status. Participants were separated into 3 groups: healthy, rotator cuff tear (RCT), and RCT and subacromial impingement syndrome (RCT+ SIS). A 3-dimensional model of the scapula was fitted to each low-dose stereoradiograph acquired with the arm at rest and 90° arm elevation. RESULTS: Orientation of the scapula with the arm at rest was not significantly different between groups. During lateral elevation, scapular orientation was not significantly different between the healthy group and the RCT group. However, upward rotation was significantly reduced in the RCT + SIS group. CONCLUSION: Alterations of scapular kinematics in symptomatic subjects are multifactorial. We observed a link between clinically assessed subacromial impingement and scapular orientation during lateral elevation of the arm.