scholarly journals Does the McRoberts’ manoeuvre need to start with thigh abduction? An innovative biomechanical study.

2020 ◽  
Author(s):  
David Desseauve ◽  
Laetitia FRADET ◽  
Robert B. GHERMAN ◽  
Yosra CHERNI ◽  
Bertrand GACHON ◽  
...  
Keyword(s):  
Motion Capture ◽  
Lumbar Lordosis ◽  
Pubic Symphysis ◽  
Biomechanical Study ◽  
Matched Pairs ◽  
Lumbar Curve ◽  
Significance Level ◽  
Starting Position ◽  
Hip Flexion ◽  
Epionics Spine

Abstract Background Guidelines and description about the achievement of the McRoberts manoeuvre are discordant, particularly concerning the need for abduction before the beginning of the manoeuvre.We sought to compare the biomechanical efficiency of the McRoberts’ manoeuvre, with and without thigh abduction. Methods In a postural comparative study, twenty-three gravidas > 32 weeks of gestational age and not in labour were assessed during three repetitions of two McRoberts’ manoeuvre that differed in terms of starting position. For the (i) McRoberts, the legs were initially placed in stirrups; for the (m) McRoberts, the legs were resting on the bed, with thighs in wide abduction. For each manoeuvre, flexion of the plane of the external conjugate of the pelvis on the spine (ANGce), hip flexion and abduction, were assessed using an optoelectronic motion capture system. Lumbar curve were assessed with Epionics Spine® system. Temporal parameters including movement duration or acceleration of the external conjugate were also computed. All values ​​obtained for the two types of manoeuvres were compared using a Wilcoxon matched-pairs signed-ranks test. The significance level was defined as p < 0.05. Results The starting position of McRoberts’ otherwise had no effect on the maximum ANGce ( p = 0.199), the minimal lordosis of the lumbar curve ( p = 0.474), or the maximal hip flexion ( p = 0.057). The other parameters were not statistically different according to the starting position ( p > 0.005). Conclusion Regardless of the starting position, the McRoberts’ manoeuvre allows ascension of the pubic symphysis and reduction of the lumbar lordosis. This results imply that the McRoberts’ manoeuvre could be performed with the legs initially placed in the stirrups.

scholarly journals Does the McRoberts’ manoeuvre need to start with thigh abduction? An innovative biomechanical study.

2019 ◽  
Author(s):  
David Desseauve ◽  
Laetitia FRADET ◽  
Robert B. GHERMAN ◽  
Yosra CHERNI ◽  
Bertrand GACHON ◽  
...  
Keyword(s):  
Motion Capture ◽  
Lumbar Lordosis ◽  
Pubic Symphysis ◽  
Biomechanical Study ◽  
Matched Pairs ◽  
Lumbar Curve ◽  
Significance Level ◽  
Starting Position ◽  
Hip Flexion ◽  
Epionics Spine

Abstract BackgroundGuidelines and description about the achievement of the McRoberts manoeuvre are discordant, particularly concerning the need for abduction before the beginning of the manoeuvre. We sought to compare the biomechanical efficiency of the McRoberts’ manoeuvre, with and without thigh abduction.Methods In a postural comparative study, twenty-three gravidas > 32 weeks of gestational age and not in labour were assessed during three repetitions of two McRoberts’ manoeuvre that differed in terms of starting position. For the (i) McRoberts, the legs were initially placed in stirrups; for the (m) McRoberts, the legs were resting on the bed, with thighs in wide abduction. For each manoeuvre, flexion of the plane of the external conjugate of the pelvis on the spine (ANGce), hip flexion and abduction, were assessed using an optoelectronic motion capture system. Lumbar curve were assessed with Epionics Spine® system. Temporal parameters including movement duration or acceleration of the external conjugate were also computed. All values ​​obtained for the two types of manoeuvres were compared using a Wilcoxon matched-pairs signed-ranks test. The significance level was defined as p < 0.05.Results The starting position of McRoberts’ otherwise had no effect on the maximum ANGce ( p = 0.199), the minimal lordosis of the lumbar curve ( p = 0.474), or the maximal hip flexion ( p = 0.057). The other parameters were not statistically different according to the starting position ( p > 0.005).Conclusion Regardless of the starting position, the McRoberts’ manoeuvre allows ascension of the pubic symphysis and reduction of the lumbar lordosis. This results imply that the McRoberts’ manoeuvre could be performed with the legs initially placed in the stirrups.

scholarly journals Assessment of Pelvic-Lumbar-Thigh Biomechanics to Optimize The Childbirth Position: An “In Vivo” Innovative Biomechanical Study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
David Desseauve ◽  
Fabrice Pierre ◽  
Anna Fernandez ◽  
Henri Panjo ◽  
Arnaud Decatoire ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Three Dimensional ◽  
Biomechanical Study ◽  
Joint Laxity ◽  
Future Research ◽  
Lumbar Curve ◽  
Hip Abduction ◽  
Hip Flexion

Abstract The study aimed to assess the associations between the pelvis orientation, lumbar curve and thigh postures throughout pregnancy in a population of healthy women. Additionally, optimal mechanical birth conditions in terms of the pelvic inlet and lumbar curve were researched. The individuals’ posture was assessed with three-dimensional motion analysis and the lumbar curve with the Epionics SPINE system. The association between the hip joint angles (flexion and abduction), the pelvis external conjugate, and lumbar curve position was assessed with a generalized linear mixed model (GLMM) adjusted to individuals’ characteristics. Joint laxity was assessed with a modified Jobbin’s extensometer. For all of the subjects, hip flexion and hip abduction were significantly associated with the angle between the external conjugate and spine, with higher correlation in the multivariate regression model. The association between hip flexion and the lumbar curve was less significant in multivariate than univariate regression analysis. Optimal birth conditions were never reached. The findings contribute to the understanding of the association between the hip position (flexion and abduction), pelvic orientation, and lumbar curve adjusted for joint laxity in healthy pregnant women. They lay the groundwork for future research in the field of obstetrical biomechanics.

scholarly journals The Impact of Spinopelvic Mobility on Arthroplasty: Implications for Hip and Spine Surgeons

2020 ◽  
Vol 9 (8) ◽  
pp. 2569 ◽  
Author(s):  
Henryk Haffer ◽  
Dominik Adl Amini ◽  
Carsten Perka ◽  
Matthias Pumberger
Keyword(s):  
Lumbar Lordosis ◽  
Flexion Contracture ◽  
Sacral Slope ◽  
Eos Imaging ◽  
Appropriate Treatment ◽  
Number Of Patients ◽  
Increased Risk ◽  
Sagittal Spinal Balance ◽  
Hip Flexion ◽  
The Impact

Spinopelvic mobility represents the complex interaction of hip, pelvis, and spine. Understanding this interaction is relevant for both arthroplasty and spine surgeons, as a predicted increasing number of patients will suffer from hip and spinal pathologies simultaneously. We conducted a comprehensive literature review, defined the nomenclature, summarized the various classifications of spinopelvic mobility, and outlined the corresponding treatment algorithms. In addition, we developed a step-by-step workup for spinopelvic mobility and total hip arthroplasty (THA). Normal spinopelvic mobility changes from standing to sitting; the hip flexes, and the posterior pelvic tilt increases with a concomitant increase in acetabular anteversion and decreasing lumbar lordosis. Most classifications are based on a division of spinopelvic mobility based on ΔSS (sacral slope) into stiff, normal, and hypermobile, and a categorization of the sagittal spinal balance regarding pelvic incidence (PI) and lumbar lordosis (LL) mismatch (PI–LL = ± 10° balanced versus PI–LL > 10° unbalanced) and corresponding adjustment of the acetabular component implantation. When performing THA, patients with suspected pathologic spinopelvic mobility should be identified by medical history and examination, and a radiological evaluation (a.p. pelvis standing and lateral femur to L1 or C7 (if EOS (EOS imaging, Paris, France) is available), respectively, for standing and sitting radiographs) of spinopelvic parameters should be conducted in order to classify the patient and determine the appropriate treatment strategy. Spine surgeons, before planned spinal fusion in the presence of osteoarthritis of the hip, should consider a hip flexion contracture and inform the patient of an increased risk of complications with existing or planned THA.

scholarly journals Lifting Heavy Patients in their Homes: A biomechanical study of equipment that can be used by EMS providers

2019 ◽  
Vol 63 (1) ◽  
pp. 984-986
Author(s):  
Steven A. Lavender ◽  
Carolyn M. Sommerich ◽  
Steven Bigelow ◽  
Eric B. Weston ◽  
Kelly Seagren ◽  
...  
Keyword(s):  
Motion Capture ◽  
Biomechanical Study ◽  
Shear Forces

Firefighters and EMS providers continue to be challenged when lifting heavy patients in their homes. This study investigated the biomechanical efficacy of four devices that could be used by two-person teams when lifting patients from the floor, from a reclining chair, or from a Simulated Inflatable Seat at chair height. Fourteen firefighter-paramedics, working in two-person teams, were instrumented with motion capture and electromyographic sensors. The Binder LiftTM and the Simple Strap were used to lift patient actors, and were compared to current lifting methods. Postural data and the peak dynamic spine shear forces at the L5/S1 level were reduced when using the Simple Strap, the Binder Lift, and the Simulated Inflatable Seat. In summary, each of these devices has been shown to have biomechanical support for their use by EMS providers.

Design and Analysis of a Shell Mechanism Based Two-Fold Force Controlled Scoliosis Brace

2017 ◽  
Author(s):  
Joep P. A. Nijssen ◽  
Giuseppe Radaelli ◽  
Just L. Herder ◽  
Charles J. Kim ◽  
J. B. Ring
Keyword(s):  
Motion Capture ◽  
Biomechanical Study ◽  
Design Approach ◽  
Correct Order ◽  
Stiffness Characteristic ◽  
Order Of Magnitude ◽  
Stiffness Profile ◽  
Critical Components ◽  
Motion Profile

In this paper a first iteration of a new scoliosis brace design and correction strategy is presented using compliant shell mechanisms to create both motion and correction. The motion profile of the human spine was found using a segmented motion capture approach. The brace was designed for a case study using a conceptual ellipsoid design approach. The force controlled correction profile was re-invented using a two fold zero and positive stiffness profile. These force generators were built and validated to prove their zero stiffness characteristic. The kinematic part of the brace was detail designed with the correct order of magnitude and validated through their force-deflection characteristic. The end result was a first iteration of a new brace validated and analysed on some critical components which can form the basis for a future biomechanical study.

Challenges of Biomechanical Data Capture in an Anthropometrically Diverse Geriatric Population at Risk for Falls

2013 ◽  
Vol 2 (1) ◽  
pp. 143-146
Author(s):  
Alexa Doig ◽  
Andrew Merryweather ◽  
Janice Morse ◽  
Donald Bloswick
Keyword(s):  
Older Adults ◽  
At Risk ◽  
Data Collection ◽  
Motion Capture ◽  
Biomechanical Study ◽  
Data Capture ◽  
Geriatric Population ◽  
Hospital Bed ◽  
Fall Arrest ◽  
Gait Impairments

A range of methodological challenges were encountered during a biomechanical study of 56 older adults ranging from ages 50-95 years of age. The sample included individuals with strength and gait impairments who were at risk for falls and fall-related injury. Methodological and participant-related issues encountered during data collection were 1) preventing falls and fall-related injuries, 2) difficulty with osteological landmark palpation and retroreflective marker placement due to obesity, 3) retroreflective marker obstruction by body fat and clothing, as well as the safety harness, hospital bed and other structures in the motion capture space, 4) marker loss during in-bed movements, 5) participant fatigue and instability necessitating trial modification. The development of a customized fall arrest system and other solutions will be discussed.

A Preliminary Biomechanical Study of Cyclic Preconditioning Effects on Canine Cadaveric Whole Femurs

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Rad Zdero ◽  
Chris H. Gallimore ◽  
Alison J. McConnell ◽  
Harshita Patel ◽  
Rosane Nisenbaum ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Biomechanical Study ◽  
Coefficient Of Determination ◽  
Displacement Curve ◽  
Matched Pairs ◽  
Cycle Number ◽  
Loading Cycle ◽  
Fresh Frozen ◽  
Practical Implications

Biomechanical preconditioning of biological specimens by cyclic loading is routinely done presumably to stabilize properties prior to the main phase of a study. However, no prior studies have actually measured these effects for whole bone of any kind. The aim of this study, therefore, was to quantify these effects for whole bones. Fourteen matched pairs of fresh-frozen intact cadaveric canine femurs were sinusoidally loaded in 4-point bending from 50 N to 300 N at 1 Hz for 25 cycles. All femurs were tested in both anteroposterior (AP) and mediolateral (ML) bending planes. Bending stiffness (i.e., slope of the force-vs-displacement curve) and linearity R2 (i.e., coefficient of determination) of each loading cycle were measured and compared statistically to determine the effect of limb side, cycle number, and bending plane. Stiffnesses rose from 809.7 to 867.7 N/mm (AP, left), 847.3 to 915.6 N/mm (AP, right), 829.2 to 892.5 N/mm (AP, combined), 538.7 to 580.4 N/mm (ML, left), 568.9 to 613.8 N/mm (ML, right), and 553.8 to 597.1 N/mm (ML, combined). Linearity R2 rose from 0.96 to 0.99 (AP, left), 0.97 to 0.99 (AP, right), 0.96 to 0.99 (AP, combined), 0.95 to 0.98 (ML, left), 0.94 to 0.98 (ML, right), and 0.95 to 0.98 (ML, combined). Stiffness and linearity R2 versus cycle number were well-described by exponential curves whose values leveled off, respectively, starting at 12 and 5 cycles. For stiffness, there were no statistical differences for left versus right femurs (p = 0.166), but there were effects due to cycle number (p < 0.0001) and AP versus ML bending plane (p < 0.0001). Similarly, for linearity, no statistical differences were noted due to limb side (p = 0.533), but there were effects due to cycle number (p < 0.0001) and AP versus ML bending plane (p = 0.006). A minimum of 12 preconditioning cycles was needed to fully stabilize both the stiffness and linearity of the canine femurs. This is the first study to measure the effects of mechanical preconditioning on whole bones, having some practical implications on research practices.

scholarly journals From Stoop to Squat: A Comprehensive Analysis of Lumbar Loading Among Different Lifting Styles

2021 ◽  
Vol 9 ◽  
Author(s):  
Michael von Arx ◽  
Melanie Liechti ◽  
Lukas Connolly ◽  
Christian Bangerter ◽  
Michael L. Meier ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Motion Capture ◽  
Repeated Measures ◽  
Lumbar Lordosis ◽  
Whole Body ◽  
Optimization Approach ◽  
Repeated Measures Design ◽  
Shear Loads ◽  
Squat Lifting ◽  
Stoop Lifting

Lifting up objects from the floor has been identified as a risk factor for low back pain, whereby a flexed spine during lifting is often associated with producing higher loads in the lumbar spine. Even though recent biomechanical studies challenge these assumptions, conclusive evidence is still lacking. This study therefore aimed at comparing lumbar loads among different lifting styles using a comprehensive state-of-the-art motion capture-driven musculoskeletal modeling approach. Thirty healthy pain-free individuals were enrolled in this study and asked to repetitively lift a 15 kg-box by applying 1) a freestyle, 2) a squat and 3) a stoop lifting technique. Whole-body kinematics were recorded using a 16-camera optical motion capture system and used to drive a full-body musculoskeletal model including a detailed thoracolumbar spine. Continuous as well as peak compressive, anterior-posterior shear and total loads (resultant load vector of the compressive and shear load vectors) were calculated based on a static optimization approach and expressed as factor body weight (BW). In addition, lumbar lordosis angles and total lifting time were calculated. All parameters were compared among the lifting styles using a repeated measures design. For each lifting style, loads increased towards the caudal end of the lumbar spine. For all lumbar segments, stoop lifting showed significantly lower compressive and total loads (−0.3 to −1.0BW) when compared to freestyle and squat lifting. Stoop lifting produced higher shear loads (+0.1 to +0.8BW) in the segments T12/L1 to L4/L5, but lower loads in L5/S1 (−0.2 to −0.4BW). Peak compressive and total loads during squat lifting occurred approximately 30% earlier in the lifting cycle compared to stoop lifting. Stoop lifting showed larger lumbar lordosis range of motion (35.9 ± 10.1°) than freestyle (24.2 ± 7.3°) and squat (25.1 ± 8.2°) lifting. Lifting time differed significantly with freestyle being executed the fastest (4.6 ± 0.7 s), followed by squat (4.9 ± 0.7 s) and stoop (5.9 ± 1.1 s). Stoop lifting produced lower total and compressive lumbar loads than squat lifting. Shear loads were generally higher during stoop lifting, except for the L5/S1 segment, where anterior shear loads were higher during squat lifting. Lifting time was identified as another important factor, considering that slower speeds seem to result in lower loads.

scholarly journals Relationship between head posture and lumbar curve in a sitting position: a biomechanical study

2017 ◽  
Vol 30 (3) ◽  
pp. 453-461 ◽  
Author(s):  
Rozilene Maria Cota Aroeira ◽  
Renata Maria Moreira Moraes Furlan ◽  
Antônio Eustáquio de Melo Pertence ◽  
Estevam Barbosa de Las Casas ◽  
Marcelo Greco
Keyword(s):  
Biomechanical Study ◽  
Equilibrium Analysis ◽  
Static Equilibrium ◽  
Horizontal Distance ◽  
Sitting Position ◽  
Lumbar Curve ◽  
Forward Head Posture ◽  
Lumbar Support ◽  
Head Posture ◽  
Extensor Muscles

Abstract Introduction: The sitting position routinely used for a wide variety of tasks increases the potential of developing forward head posture, which can seriously compromise the health of different systems in the human body. Objective: A static equilibrium analysis was conducted, comparing the position of the head with the lumbar curve in three different sitting positions. Methods: The approximate force and flexion moment of the head extensor muscles in static equilibrium was calculated in each of the following positions: (A) without a backrest; (B) using a backrest with a 100° tilt angle; (C) using a 100° tilted backrest associated with a cylindrical lumbar support cushion at the level of the L3 vertebra. Results: The C7-tragus angles were 43°, 50° and 52°; Frankfort horizontal plane (FH) angles were 5°, 9° and 9°; force of the head extensor muscles was 53.0N, 59.7N and 43.5N and flexion moments were 2.60Nm, 2.05Nm and 1.78Nm, in positions A, B and C, respectively. Conclusion: The results revealed that the sitting position using a 100° tilted backrest and lumbar support with the smallest L3-tragus horizontal distance required less effort by the head and neck extensor muscles to retain the head in equilibrium. This study demonstrated the need to preserve the physiology of the lumbar spine, characterized by the position of the L3 vertebra, in order to ensure good head position.

Does teaching ethics do any good?

2016 ◽  
Vol 58 (4) ◽  
pp. 439-454 ◽  
Author(s):  
Elizabeth Prior Jonson ◽  
Linda McGuire ◽  
Brian Cooper
Keyword(s):  
Business Ethics ◽  
Ethics Education ◽  
Ethical Decision Making ◽  
Ethical Behaviour ◽  
Matched Pairs ◽  
Business Ethics Education ◽  
Content Type ◽  
Starting Position ◽  
Before And After ◽  
Positive Effect

Purpose – This matched-pairs study of undergraduates at an Australian University investigates whether business ethics education has a positive effect on student ethical behaviour. The paper aims to discuss this issue. Design/methodology/approach – This study uses a matched-pairs design to look at responses before and after students have taken a semester-long unit in business ethics. The authors used ethical scenarios and analysed both the starting position and changes in responses for the total student group, and by gender and citizenship. Findings – The results from this matched-pairs study show ethics education has a limited impact on students’ responses to ethical dilemmas. Practical implications – Ethics subjects are now ubiquitous in business schools, but it may be time to consider alternatives to the philosophical normative teaching approach. Originality/value – This paper is significant in that it uses 142 matched pairs to look at responses before and after students have taken a semester-long unit in business ethics. This study provides qualified support for the proposition that business ethics education has an impact on students’ ethical decision making.

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