scholarly journals Evaluation of an acceleration-based assistive strategy to control a back-support exoskeleton for manual material handling

2020 ◽  
Vol 1 ◽  
Author(s):  
Maria Lazzaroni ◽  
Ali Tabasi ◽  
Stefano Toxiri ◽  
Darwin G. Caldwell ◽  
Elena De Momi ◽  
...  
Keyword(s):  
Control Strategy ◽  
Material Handling ◽  
Muscle Activation ◽  
Control Strategies ◽  
Angular Acceleration ◽  
Movement Speed ◽  
Compression Force ◽  
Back Muscle ◽  
Manual Material Handling ◽  
New Strategy

Abstract To reduce the incidence of occupational musculoskeletal disorders, back-support exoskeletons are being introduced to assist manual material handling activities. Using a device of this type, this study investigates the effects of a new control strategy that uses the angular acceleration of the user’s trunk to assist during lifting tasks. To validate this new strategy, its effectiveness was experimentally evaluated relative to the condition without the exoskeleton as well as against existing strategies for comparison. Using the exoskeleton during lifting tasks reduced the peak compression force on the L5S1 disc by up to 16%, with all the control strategies. Substantial differences between the control strategies in the reductions of compression force, lumbar moment and back muscle activation were not observed. However, the new control strategy reduced the movement speed less with respect to the existing strategies. Thanks to improved timing in the assistance in relation to the typical dynamics of the target task, the hindrance to typical movements appeared reduced, thereby promoting intuitiveness and comfort.

scholarly journals Patient-Centered Robot-Aided Passive Neurorehabilitation Exercise Based on Safety-Motion Decision-Making Mechanism

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Lizheng Pan ◽  
Aiguo Song ◽  
Suolin Duan ◽  
Zhuqing Yu
Keyword(s):  
Decision Making ◽  
Control Strategy ◽  
Position Control ◽  
Impedance Control ◽  
Control Strategies ◽  
Movement Speed ◽  
Stroke Patients ◽  
Patient Centered ◽  
Motion Speed ◽  
Clinical Experiments

Safety is one of the crucial issues for robot-aided neurorehabilitation exercise. When it comes to the passive rehabilitation training for stroke patients, the existing control strategies are usually just based on position control to carry out the training, and the patient is out of the controller. However, to some extent, the patient should be taken as a “cooperator” of the training activity, and the movement speed and range of the training movement should be dynamically regulated according to the internal or external state of the subject, just as what the therapist does in clinical therapy. This research presents a novel motion control strategy for patient-centered robot-aided passive neurorehabilitation exercise from the point of the safety. The safety-motion decision-making mechanism is developed to online observe and assess the physical state of training impaired-limb and motion performances and regulate the training parameters (motion speed and training rage), ensuring the safety of the supplied rehabilitation exercise. Meanwhile, position-based impedance control is employed to realize the trajectory tracking motion with interactive compliance. Functional experiments and clinical experiments are investigated with a healthy adult and four recruited stroke patients, respectively. The two types of experimental results demonstrate that the suggested control strategy not only serves with safety-motion training but also presents rehabilitation efficacy.

On the Stability Analysis of the Human Spine

2003 ◽  
Author(s):  
M. El-Rich ◽  
A. Shirazi-Adl
Keyword(s):  
Stability Analysis ◽  
Material Handling ◽  
Muscle Activation ◽  
The Body ◽  
Abdominal Pressure ◽  
Human Spine ◽  
Manual Material Handling ◽  
The Stability ◽  
Force Relationship

The stability of the human spine in compression has attracted a considerable amount of attention in recent years. The passive ligamentous thoracolumbar and lumbar spines are known to exhibit large displacements or hypermobility (i.e., instability in an imperfect column) under compression loads <100N. Since such compression loads are only a small fraction of those supported by the spine even in regular daily activities, let aside the manual material handling tasks, the question arises as to how the spine is stablized in vivo? Various stabilizing mechanisms have been proposed and investigated; wrapping loading [Shirazi-Adl and Parnianpour, 2000], postural adaptations [Shirazi-Adl and parnianpor, 1999], intra-abdominal pressure [Cholewicki et al, 1999] and muscle activation/coactivation [Bergmark, 1989; Crisco and Panjabi, 1991]. In this work, a novel kinematics-based methad [Shirazi-Adl et al., 2002] is first applied to compute muscle forces and internal loads in standing postures under gravity with or without 200N loads held either on sides or close to the body in front. The stability of the system under given loads and prescribed postures is sudsequently examined using both linear bucking analysis based on the deformed configurations and nonlinear analysis while employing a liner stiffness-force relationship for muscules [Bergmark, 1989; Crico and Panjabi, 1991]. The relative accuracy of foregoing methods in stability analysis of some sample structures is also investigated. Moreover, the effect of co-activity on stability of the spine in neutral postures is studied.

scholarly journals Activation of pelvic floor, lumbar and abdominal musculature during a simulated manual material handling task: a cross-sectional study

2020 ◽  
Vol 27 (3) ◽  
pp. 335-344
Author(s):  
Fernanda Cabegi de Barros ◽  
Patricia Driusso ◽  
Fernanda Roberto ◽  
Mariana Vieira Batistão ◽  
Mikaela Corrêa ◽  
...  
Keyword(s):  
Pelvic Floor ◽  
Material Handling ◽  
Muscle Activation ◽  
Cross Sectional Study ◽  
Pelvic Floor Muscles ◽  
Abdominal Muscles ◽  
Sectional Study ◽  
Cross Sectional ◽  
Abdominal Musculature ◽  
Manual Material Handling

ABSTRACT Pelvic floor muscles act synergistically with the abdominal and lumbar muscles contributing to spine and pelvic control. These muscles are activated during activities that increase intra-abdominal pressure, such as manual material handling. The aim of our study was to assess the electrical activity of the lumbar, abdominal and pelvic floor muscles during manual material handling with different loads. This is a cross-sectional study with sixteen nulliparous continent women aged between 18 and 35 years. An electromyographic system was used to evaluate the activation of the multifidus, erector spinal (iliocostal) and abdominal rectus muscles bilaterally (Trigno Wireless®, DelSys®, Boston, USA) and another for the pelvic floor muscles (Thought Technology Ltd, Canadá). Electromyographic data were collected during manual handling of three loads: light (1.5 kg), medium (4.5 kg) and heavy (11.3 kg). Repeated measures ANOVA was applied to compare the activation among loads at a 5% level of significance (α = 0.05). There was a significant increase in the activation of the lumbar and abdominal musculature as the load increases. No difference among loads was found for the pelvic floor muscle activation. Pelvic floor muscles did not increase their activation in function of the load, as occur for the lumbar and abdominal muscles in nulliparous continent women. These findings need to be confirmed for incontinent woman, since it could have clinical implications for designing both occupational tasks and pelvic floor rehabilitation.

scholarly journals Quantification and classification of low back pain severity based on Aberdeen low back pain scale

2015 ◽  
Vol 7 (1) ◽  
pp. 92-97
Author(s):  
Kumkum Pandey ◽  
Deepa Vinay
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Material Handling ◽  
Control Strategies ◽  
Pain Scale ◽  
Low Back ◽  
Manual Material Handling ◽  
Risk Of Injury ◽  
Safety And Health ◽  
Occupational Low Back Pain

Occupational low back pain (LBP) remains the leading safety and health challenge for many industries. The present study was focused to evaluate the physical demands of the manual material handling task in terms of back pain to assess the potential risk of injury. This investigation measures the prevalence of low back pain of rice mill workers in Rudrapur block, District Udhamsingh Nagar, Uttarakhand. Sixty workers, extensively involved in manual material handling (MMH) task (including, loading, unloading, stacking, filling carrying of rice or paddy sack etc.) were investigated for the presence of low back pain and associated personal and workplace risk factors and symptoms. The severity, intensity; frequency, duration and medication of low back pain was assessed utilizing the ‘Aberdeen Low Back Pain Scale’ developed by Ruta and Garratt (1994) on the basis of scoring in terms of light, moderately light, heavy , very heavy and extremely heavy back pain. The interpretation of scores revealed that 18.33 % respondents were falling under the category of moderately light pain (M), 66.66 % respondents were under heavy back pain (H), only 15 % were under the category of very heavy back pain (V), whereas none of the respondents were under the category of light pain (l) and extremely heavy pain (E). It was concluded that there remains an interest in developing integrated models to predict LBP among Rice mill workers using ergonomic and psychosocial factors as well as control strategies to reduce risk of injury.

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