Comparison of Biomechanical Human Neck Models: Muscle Forces and Spinal Loads at C4/5 Level

1999 ◽  
Vol 15 (2) ◽  
pp. 120-138 ◽  
Author(s):  
Hyeonki Choi ◽  
Ray Vanderby
Keyword(s):  
Cervical Spine ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Distribution Patterns ◽  
Muscle Forces ◽  
Spinal Loads ◽  
Joint Loads ◽  
Electromyographic Signals ◽  
Male Subjects ◽  
Maximum Exertion

This study developed a three-dimensional biomechanical model to investigate the internal loads on the human neck that result from isometrically generated loads resisted by a force on the head. The first goal was to apply the double-optimization (DOPT) method, the EMG-based method, and the EMG assisted optimization (EMGAO) method to the neck model, calculating muscle forces and C4/5 cervical joint loads for each method. The second goal was to compare the results of the different methods, and the third was to determine maximum exertion forces in the cervical spine for isometric contractions. To formulate the EMG-based model, electromyographic signals were collected from 10 male subjects. EMG signals were obtained from 8 sites around the C4/5 level of the neck by surface electrodes, while the subject performed near maximum, isometric exertions. The mean maximum values (±SD) calculated for C4/5 joint compressive forces during peak exertions were 1654 (±308) N in flexion by the EMG method, 1674 (±319) N in flexion by the EMGAO method, and 1208 (±123) N in extension by the DOPT method. In contrast to the DOPT method, the EMG and EMGAO methods showed activation of all the muscles, including the antagonists, and accommodated various load distribution patterns among the agonist muscles during generation of the same magnitude of moments, especially in lateral bending. The EMG and EMGAO methods predicted higher cervical spinal loads than previously published results by the DOPT method. These results may be helpful to engineers and surgeons who are designing and using cervical spine implants and instrumentation.

The Effect of Lifting vs. Lowering on Spinal Loading

1996 ◽  
Vol 40 (13) ◽  
pp. 599-603 ◽  
Author(s):  
Kermit G. Davis
Keyword(s):  
Muscle Activity ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Muscle Forces ◽  
Shear Forces ◽  
Spinal Loading ◽  
Spinal Loads ◽  
Trunk Strength ◽  
Anterior Posterior ◽  
Three Dimensional Space

In industry, workers perform tasks requiring both lifting and lowering. During concentric lifting, the muscles are shortening as the force is being generated. Conversely, the muscle lengthens while generating force during eccentric lowering. While research on various lifting tasks is extensive, there has been limited research performed to evaluate the lowering tasks. Most of the research that does exist on lowering has investigated muscle activity and trunk strength. None of these studies have investigated spinal loading. The current study estimated the effects of lifting and lowering on spinal loads and predicted moments imposed on the spine. Ten subjects performed both eccentric and concentric lifts under sagittally symmetric conditions. The tasks were performed under isokinetic trunk velocities of 5, 10, 20, 40, and 80 deg/s while holding a box with weights of 9.1, 18.2, and 27.3 kg. Spinal loads and predicted moments in three dimensional space were estimated by an EMG-assisted model which has been adjusted to incorporate the artifacts of eccentric lifting. Eccentric strength was found to be 56 percent greater than during concentric lifting. The lowering tasks produced significantly higher compression forces but lower anterior-posterior shear forces than the concentric lifting tasks. The differences in the spinal loads between the two lifting tasks were attributed to the internal muscle forces and unequal moments resulting from differences in the lifting path of the box. Thus, the differences between the lifting tasks resulted from different lifting styles associated with eccentric and concentric movements

scholarly journals Optimization-Based Biomechanical Evaluation of Isometric Exertions on a Brake Wheel

1993 ◽  
Vol 37 (10) ◽  
pp. 693-696 ◽  
Author(s):  
Christian A. Johnson ◽  
Jeffrey C. Woldstad
Keyword(s):  
Repeated Measures ◽  
Three Dimensional ◽  
Compressive Force ◽  
Biomechanical Model ◽  
The Body ◽  
Body Posture ◽  
Muscle Forces ◽  
Left Hand ◽  
Lumbar Muscle ◽  
External Forces

A static three-dimensional low-back biomechanical model was developed to estimate the levels of compressive force on the L3/L4 spinal joint during an experiment that simulated wheel turning. We recorded three-dimensional body posture and the resultant forces at the hands for analysis by the model. The model employed a standard link analysis procedure to resolve the external forces acting on the body to a resultant moment about L3/L4. The model then implemented an optimization algorithm to estimate the internal lumbar muscle forces generated to resist the external forces. The muscle forces and external forces were added to arrive at a prediction of compressive force at L3/L4. The experiment investigated the effects of general body posture, left hand grip, gender, and hand brake torque level upon predicted compressive force at L3/L4. A repeated measures analysis of variance (ANOVA) revealed all but one main effect and some interaction effects to be significant at p<0.05. Average predicted L3/L4 compressive forces at maximum wheel torque levels ranged from 1644N for females to 6926N for large males.

The Effect of a Variable Lumbar Erector Spinae Sagittal Plane Moment Arm on Predicted Spinal Loading

2002 ◽  
Vol 46 (13) ◽  
pp. 1061-1065
Author(s):  
Michael J. Jorgensen ◽  
William S. Marras ◽  
Thomas R. Waters
Keyword(s):  
Sagittal Plane ◽  
Biomechanical Model ◽  
Large Degree ◽  
Erector Spinae ◽  
Moment Arm ◽  
Spinal Loading ◽  
Spinal Loads ◽  
Neutral Posture ◽  
Lifting Task ◽  
Male Subjects

Recent research indicates that the sagittal plane moment arm of the erector spinae decreases at the L5/S1 level during torso flexion. The objective of this study was to assess the predicted L5/S1 spinal loading from a lifting task when allowing the erector spinae sagittal plane moment arm to vary during torso flexion. Nineteen male subjects lifted three loads from two origin locations to an upright neutral posture. Spinal loading was predicted from an EMG-assisted biomechanical model that allowed the erector spinae moment arm to vary during torso flexion. The predicted lateral, anterior-posterior shear and compression forces increased by 7.4%, 11.1% and 6.6%, respectively, when compared to using a biomechanical model that kept the erector spinae moment arm constant. These results suggest that models that account for the varying erector spinae moment arm predict greater spinal loads, especially for motions that involve a large degree of torso flexion.

A 3D Biomechanical Model of the Hand for Power Grip

2003 ◽  
Vol 125 (1) ◽  
pp. 78-83 ◽  
Author(s):  
Joaquı´n L. Sancho-Bru ◽  
A. Pe´rez-Gonza´lez ◽  
M. Vergara ◽  
D. J. Giurintano
Keyword(s):  
Three Dimensional ◽  
Biomechanical Model ◽  
Muscle Forces ◽  
Power Grip ◽  
Grasping Force ◽  
Different Diameters ◽  
Power Grasp

A three-dimensional scalable biomechanical model of the four fingers of the hand to evaluate power grip is proposed. The model has been validated by means of reproducing an experiment in which the subjects exerted the maximal voluntary grasping force over cylinders of different diameters. The model is used to simulate the cylinder grip for two hand sizes and for five different handle diameters. The reduction of the muscle forces using different handle diameters has been studied. The model can be applied to the design and evaluation of handles for power grip and to the study of power grasp for normal and abnormal hands.

Three-dimensional analysis of active head and cervical spine range of motion: effect of age in healthy male subjects

2002 ◽  
Vol 17 (8) ◽  
pp. 611-614 ◽  
Author(s):  
Chiarella Sforza ◽  
GianPiero Grassi ◽  
Nicola Fragnito ◽  
Michela Turci ◽  
Virgilio F Ferrario
Keyword(s):  
Cervical Spine ◽  
Range Of Motion ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Healthy Male ◽  
Motion Effect ◽  
Male Subjects ◽  
Effect Of Age

scholarly journals Improving 3D-3D facial registration methods: potential role of three-dimensional models in personal identification of the living

2021 ◽  
Author(s):  
Daniele Gibelli ◽  
Andrea Palamenghi ◽  
Pasquale Poppa ◽  
Chiarella Sforza ◽  
Cristina Cattaneo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Personal Identification ◽  
Surveillance Systems ◽  
3D Registration ◽  
Three Dimensional Models ◽  
Point To Point ◽  
Point Distance ◽  
Male Subjects

AbstractPersonal identification of the living from video surveillance systems usually involves 2D images. However, the potentiality of three-dimensional facial models in gaining personal identification through 3D-3D comparison still needs to be verified. This study aims at testing the reliability of a protocol for 3D-3D registration of facial models, potentially useful for personal identification. Fifty male subjects aged between 18 and 45 years were randomly chosen from a database of 3D facial models acquired through stereophotogrammetry. For each subject, two acquisitions were available; the 3D models of faces were then registered onto other models belonging to the same and different individuals according to the least point-to-point distance on the entire facial surface, for a total of 50 matches and 50 mismatches. RMS value (root mean square) of point-to-point distance between the two models was then calculated through the VAM® software. Intra- and inter-observer errors were assessed through calculation of relative technical error of measurement (rTEM). Possible statistically significant differences between matches and mismatches were assessed through Mann–Whitney test (p < 0.05). Both for intra- and inter-observer repeatability rTEM was between 2.2 and 5.2%. Average RMS point-to-point distance was 0.50 ± 0.28 mm in matches, 2.62 ± 0.56 mm in mismatches (p < 0.01). An RMS threshold of 1.50 mm could distinguish matches and mismatches in 100% of cases. This study provides an improvement to existing 3D-3D superimposition methods and confirms the great advantages which may derive to personal identification of the living from 3D facial analysis.

scholarly journals Spatiotemporal Analysis of COVID-19 Spread with Emerging Hotspot Analysis and Space–Time Cube Models in East Java, Indonesia

2021 ◽  
Vol 10 (3) ◽  
pp. 133
Author(s):  
Purwanto Purwanto ◽  
Sugeng Utaya ◽  
Budi Handoyo ◽  
Syamsul Bachri ◽  
Ike Sari Astuti ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Distribution Patterns ◽  
Spatiotemporal Analysis ◽  
Space Time ◽  
Road Density ◽  
Hotspot Analysis ◽  
Spatiotemporal Information ◽  
Depth Analysis ◽  
Analysis Models ◽  
Oscillating Patterns

In this research, we analyzed COVID-19 distribution patterns based on hotspots and space–time cubes (STC) in East Java, Indonesia. The data were collected based on the East Java COVID-19 Radar report results from a four-month period, namely March, April, May, and June 2020. Hour, day, and date information were used as the basis of the analysis. We used two spatial analysis models: the emerging hotspot analysis and STC. Both techniques allow us to identify the hotspot cluster temporally. Three-dimensional visualizations can be used to determine the direction of spread of COVID-19 hotspots. The results showed that the spread of COVID-19 throughout East Java was centered in Surabaya, then mostly spread towards suburban areas and other cities. An emerging hotspot analysis was carried out to identify the patterns of COVID-19 hotspots in each bin. Both cities featured oscillating patterns and sporadic hotspots that accumulated over four months. This pattern indicates that newly infected patients always follow the recovery of previous COVID-19 patients and that the increase in the number of positive patients is higher when compared to patients who recover. The monthly hotspot analysis results yielded detailed COVID-19 spatiotemporal information and facilitated more in-depth analysis of events and policies in each location/time bin. The COVID-19 hotspot pattern in East Java, visually speaking, has an amoeba-like pattern. Many positive cases tend to be close to the city, in places with high road density, near trade and business facilities, financial storage, transportation, entertainment, and food venues. Determining the spatial and temporal resolution for the STC model is crucial because it affects the level of detail for the information of endemic disease distribution and is important for the emerging hotspot analysis results. We believe that similar research is still rare in Indonesia, although it has been done elsewhere, in different contexts and focuses.

scholarly journals Analysis of squat and stoop dynamic liftings: muscle forces and internal spinal loads

2006 ◽  
Vol 16 (5) ◽  
pp. 687-699 ◽  
Author(s):  
Babak Bazrgari ◽  
Aboulfazl Shirazi-Adl ◽  
Navid Arjmand
Keyword(s):  
Muscle Forces ◽  
Spinal Loads
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