Volitional Postures during Maximal Push/Pull Exertions in the Sagittal Plane

1981 ◽  
Vol 25 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Don B. Chaffin ◽  
Mark Olson ◽  
Arun Garg
Keyword(s):  
Sagittal Plane ◽  
Isometric Force ◽  
Load Cell ◽  
Actual Performance ◽  
Pull Force ◽  
Foot Placement ◽  
Biomechanical Models ◽  
Body Joints ◽  
Direct Feedback ◽  
Push And Pull

A set of push/pull experiments were performed by six subjects (3 men and 3 women of widely varying anthropometry). They were asked to exert maximal one-handed and two-handed push and pull forces on a load cell set at three different heights: (67, 109 and 152 cm). They were each permitted to experiment with their postures to determine that which they sensed would permit the largest push or pull force, though no direct feedback was given as to their actual performance. Once they achieved what they believed to be their optimal posture, sagittal plane photographs were taken. The angles of major body joints were then recorded along with the isometric force produced. It is shown that foot placement (together or spread apart, close or distant from the load cell), handle height, and body postures affect push and pull force capability in a manner that is reasonably logical, using biomechanical concepts. It is proposed that future biomechanical models of push and pull strengths and workplace layouts must be carefully assessed with reference to the postural variations reported.

scholarly journals Experimental push and pull force data utilizing self-developed automatic liquid dispensers

Data in Brief ◽  
2021 ◽  
pp. 107308
Author(s):  
Agustami Sitorus ◽  
Irwin syahri Cebro ◽  
Devianti ◽  
Ramayanty Bulan
Keyword(s):  
Pull Force ◽  
Push And Pull ◽  
Force Data

The Biomechanics of Lower Extremity Action in Distance Running

Foot & Ankle ◽  
1987 ◽  
Vol 7 (4) ◽  
pp. 197-217 ◽  
Author(s):  
Peter R. Cavanagh
Keyword(s):  
Lower Extremity ◽  
Sagittal Plane ◽  
Plane Motion ◽  
Common Finding ◽  
Distance Running ◽  
Foot Placement ◽  
Running Injuries ◽  
Acceleration Force ◽  
Rearfoot Motion ◽  
Insight Into

The role of quantitative biomechanical measurements in the evaluation of the running patient is discussed. Many techniques are now available to provide insight into the external mechanics of lower extremity action during running, and results from such measurements are presented for symptom-free subjects at distance running speeds. Details of stride length, stride time, and foot placement are first presented followed by a discussion of kinematic data, including stick figures, angle-time graphs, and angle-angle diagrams for the sagittal plane motion of the hip, knee, and ankle joints. The measurement of rearfoot motion, as an approximation of coronal plane subtalar joint movements, is also discussed. Results from acceleration, force, and pressure measurements are considered, and the assertion is made that bilateral asymmetry in many of these measures is a fairly common finding. There are, at present, few reports in the literature of the application of biomechanical techniques to the evaluation of patients with running injuries. It is anticipated that there will be rapid developments in this area in the future and that this will provide considerable insight into the etiology, diagnosis, and treatment of running injuries.

scholarly journals The design of attendant propelled wheelchairs

1991 ◽  
Vol 15 (1) ◽  
pp. 38-45 ◽  
Author(s):  
E. W. Abel ◽  
T. G. Frank
Keyword(s):  
Sagittal Plane ◽  
Biomechanical Analysis ◽  
Upper Body ◽  
Published Data ◽  
New Approach ◽  
Factors Associated ◽  
Centre Of Gravity ◽  
Lower Back ◽  
Mechanical Factors ◽  
Body Joints

The attendant operated wheelchair is propelled by applying forces to handles at the rear of the chair. There are no published data to justify the design of pushing handles on existing wheelchairs. In Dundee, studies of pushing have been conducted in order to obtain subjective preferences for location and design of handles and an understanding of bio-mechanical factors associated with wheelchair pushing. Preferred positions for handles have been found to be in the region of 0.75 of shoulder height, 1.14 times shoulder width although deviations of +5% in these values are still rated as acceptable. The preferred positions do not correspond to minimum levels of resultant force or with lowest levels of moment in any of the upper body joints. Moments occurring at the lower back are not substantially affected by handle position. The biomechanical analysis so far has not revealed why some handle positions are more comfortable for pushing than others. Further study, involving calculation of resultant moments (rather than just sagittal plane moments) at these joints and at the lower body joints, is a next step in attempting to find the indicators of discomfort. Transferring a patient from or to a wheelchair can be a difficult operation with risks of accidents to the patient through falling and risks to the attendant of strain, particularly to the back. Current footrests on wheelchairs are a major source of the problems during transfer. A new approach to footrest design is described which solves these difficulties by using a footrest that lowers onto the floor. This has other attractive features such as providing good stability and restraint of the chair during transfer. The armrests are also discussed since they have a role to play where patients can assist themselves during transfer but have the potential for being an obstruction when patients need to be lifted from wheelchairs. The ease of pushing and manoeuvring, the difficulties caused by obstacles such as carpet edges and lift entrances, the operation of the brakes, and the position of the pushing handles are all important aspects of chairs used for transporting patients. The wheels, particularly the wheel diameter, tyre compressibility and castor trail, are determinants of the mobility aspects. However, the position of the wheels in relation to the centre of gravity and whether the castors are at the front or rear must also be considered. The brakes, as well as being effective, should be easy to apply and not too affected by wear. A prototype wheelchair is described which incorporates design features suggested by research into the above considerations.

Sensitivity of Neck Musculoskeletal Model Predictions to Variation in Intervertebral Kinematics

2013 ◽  
Author(s):  
Derek D. Nevins ◽  
Liying Zheng ◽  
Anita N. Vasavada
Keyword(s):  
Sagittal Plane ◽  
Center Of Mass ◽  
Chronic Neck Pain ◽  
Neck Muscle ◽  
Neck Extension ◽  
In Vivo Measurement ◽  
Biomechanical Models ◽  
Neck Strength ◽  
Flexion Strength

In-vivo measurement of loads and displacements in the head and neck is very difficult. Musculoskeletal biomechanical models are useful tools for investigating biomechanical phenomena in this system, but they require several assumptions and simplifications regarding tissue mechanical properties and intervertebral kinematics (IVK). In particular, IVK show considerable variation among subjects [1], and quantifying the influence of this variation on model estimates is important for the application of models toward understanding neck biomechanical function. Variation in IVK parameters may affect model estimates of neck strength (neck muscle moment, the product of muscle force and muscle moment arm), as well as the location of the head center of mass, which influences the gravitational load on the neck due to the weight of the head. The magnitude of gravitational load relative to neck extension strength, referred to here as fatiguability, is an estimate of demand on neck muscles and may be related to chronic neck pain induced by forward head postures [2]. The goal of this study was to quantify variation in model estimates of flexion strength, extension strength and fatigability over sagittal plane postures, due to variation in IVK.

Modularity of Motor Output Evoked By Intraspinal Microstimulation in Cats

2004 ◽  
Vol 91 (1) ◽  
pp. 502-514 ◽  
Author(s):  
Michel A. Lemay ◽  
Warren M. Grill
Keyword(s):  
Muscle Activation ◽  
Sagittal Plane ◽  
Force Fields ◽  
Isometric Force ◽  
Force Transducer ◽  
Spinal Reflexes ◽  
Lumbar Spinal Cord ◽  
Emg Activity ◽  
Active Force ◽  
Spinal Circuitry

We studied the forces produced at the cat's hindpaw by microstimulation of the ipsi- and contralateral lumbar spinal cord in spinal intact α-chloralose anesthetized ( n = 3) or decerebrate ( n = 3) animals. Isometric force and EMG responses were measured at 9-12 limb configurations, with the paw attached to a force transducer and with the hip and femur fixed. The active forces elicited at different limb configurations were summarized as force fields representing the sagittal plane component of the forces produced at the paw throughout the workspace. The forces varied in amplitude over time but the orientations were stable, and the pattern of an active force field was invariant through time. The active force fields divided into four distinct types, and a few of the fields showed convergence to an equilibrium point. The fields were generally produced by coactivation of the hindlimb muscles. In addition, some of the fields were consistent with known spinal reflexes and the stimulation sites producing them were in laminae where the interneurons associated with those reflexes are known to be located. Muscle activation produced by intraspinal stimulation, as assessed by intramuscular EMG activity, was modified with limb configuration, suggesting that the responses were not fixed, but were modified by position-dependent sensory feedback. The force responses may represent basic outputs of the spinal circuitry and may be related to similar spinal primitives found in the frog and rat.

Influence of dynamic factors on calculating cumulative low back loads

2005 ◽  
Vol 5 (2) ◽  
pp. 89-97
Author(s):  
Jack P. Callaghan ◽  
Kiera Keown ◽  
David M. Andrews
Keyword(s):  
Dynamic Model ◽  
Sagittal Plane ◽  
Average Error ◽  
Low Back ◽  
Materials Handling ◽  
Biomechanical Models ◽  
Modeling Approaches ◽  
Video Recordings ◽  
Dynamic Factors ◽  
Manual Materials Handling

This study examined the error induced in estimating cumulative low back loading for exposure to dynamic manual materials handling tasks by using either static or quasi-dynamic biomechanical models when compared to a dynamic model. Ten male subjects performed three sagittal plane lifting tasks at three different lifting speeds and using three different hand loads. Digitized video recordings and measured hand forces were collected in order to calculate cumulative L4/L5 spinal loading (compression, moment, joint shear, and reaction shear) using rigid link and single muscle equivalent biomechanical models. Cumulative loading was calculated using three modeling approaches: static, quasi-dynamic, and dynamic. The calculation of cumulative loading using the dynamic model was set as the "gold standard" and error in the static and quasi-dynamic approaches was determined by comparison with the dynamic model. The use of a quasi-dynamic model resulted in an average error of −2.76% across all 10 subjects, 3 tasks, 3 lifting speeds and 3 masses. The static model had an average error of −12.55%. The error in both modeling approaches was significantly effected by the type of task performed, mass lifted, speed of lift, and model variable examined indicating that neither model produced consistent errors across the lifting parameters. The small errors associated with the quasi-dynamic model indicates that it holds promise as a method to reduce the amount of data required to estimate cumulative loading yet still preserve the dynamic loading exposure of a manual materials handling task.

A Novel Theoretical Framework for the Dynamic Stability Analysis, Movement Control, and Trajectory Generation in a Multisegment Biomechanical Model

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Kamran Iqbal ◽  
Anindo Roy
Keyword(s):  
Postural Control ◽  
Force Feedback ◽  
Sagittal Plane ◽  
Muscle Length ◽  
Muscle Stiffness ◽  
Proprioceptive Feedback ◽  
Neural Pathways ◽  
Postural Control System ◽  
Movement Trajectories ◽  
Biomechanical Models

We consider a simplified characterization of the postural control system that embraces two broad components: one representing the musculoskeletal dynamics in the sagittal plane and the other representing proprioceptive feedback and the central nervous system (CNS). Specifically, a planar four-segment neuromusculoskeletal model consisting of the ankle, knee, and hip degrees-of-freedom (DOFs) is described in this paper. The model includes important physiological constructs such as Hill-type muscle model, active and passive muscle stiffnesses, force feedback from the Golgi tendon organ, muscle length and rate feedback from the muscle spindle, and transmission latencies in the neural pathways. A proportional-integral-derivative (PID) controller for each individual DOF is assumed to represent the CNS analog in the modeling paradigm. Our main hypothesis states that all stabilizing PID controllers for such multisegment biomechanical models can be parametrized and analytically synthesized. Our analytical and simulation results show that the proposed representation adequately shapes a postural control that (a) possesses good disturbance rejection and trajectory tracking, (b) is robust against feedback latencies and torque perturbations, and (c) is flexible to embrace changes in the musculoskeletal parameters. We additionally present detailed sensitivity analysis to show that control under conditions of limited or no proprioceptive feedback results in (a) significant reduction in the stability margins, (b) substantial decrease in the available stabilizing parameter set, and (c) oscillatory movement trajectories. Overall, these results suggest that anatomical arrangement, active muscle stiffness, force feedback, and physiological latencies play a major role in shaping motor control processes in humans.

scholarly journals Functional Method for Joints Parameters Assessment in Human Body Modeling

2019 ◽  
Vol 8 (10) ◽  
pp. 1085-1089
Keyword(s):  
Gait Analysis ◽  
Sagittal Plane ◽  
Standard Technique ◽  
Optimization Method ◽  
Functional Method ◽  
Human Motion ◽  
The Body ◽  
Lower Limbs ◽  
Human Model ◽  
Biomechanical Models

The integration of proper algorithms and computer graphics-based systems seems promising for the design of biomechanical models and the relative motion analysis. Thus, consequences on research fields as gait analysis are gathered, focusing on joints kinematics. Human motion patterns are indeed directly influenced from human model and associated joints parameters, such as centers and axes of rotation. These, as a matter of fact, determine the body segments coordinates systems. Joints parameters are estimated with several methods. The aim of this research is to evaluate the consistency of a functional approach versus a the predictive one. A validation of the algorithm used to estimate the lower limbs joints centers in gait analysis is provided with a proper subject-specific multibody model implemented in OpenSim space. Joints angles are estimated using a global optimization method and a comparison with the gold standard technique is also discussed. Overall the obtained results are consistent for the two different methodologies. The correlation of the curves is excellent in the sagittal plane, and very good in the coronal and transversal plane.

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