Significance of Lower Body Postures in Chair Design

Objective This study examined a system-level perspective to investigate the changes in the whole trunk and head postures while sitting with various lower extremity postures. Background Sitting biomechanics has focused mainly on the lumbar region only, whereas the anatomy literature has suggested various links from the head and lower extremity. Method Seventeen male participants were seated in six lower extremity postures, and the trunk kinematics and muscle activity measures were captured for 5 s. Results Changes in the trunk-thigh angle and the knee angle affected the trunk and head postures and muscle recruitment patterns significantly, indicating significant interactions between the lower extremity and trunk while sitting. Specifically, the larger trunk-thigh angle (T135°) showed more neutral lumbar lordosis (4.0° on average), smaller pelvic flexion (1.8°), smaller head flexion (3.3°), and a less rounded shoulder (1.7°) than the smaller one (T90°). The smaller knee angle (K45°) revealed a more neutral lumbar lordosis (6.9°), smaller pelvic flexion (9.2°), smaller head flexion (2.6°), and less rounded shoulder (2.4°) than the larger condition (K180°). The more neutral posture suggested by the kinematic measures confirmed significantly less muscular recruitment in the trunk extensors, except for a significant antagonistic co-contraction. Conclusion The lower and upper back postures were more neutral, and back muscle recruitment was lower with a larger trunk-thigh angle and a smaller knee angle, but at the cost of antagonistic co-contraction. Application The costs and benefits of each lower extremity posture can be used to design an ergonomic chair and develop an improved sitting strategy.

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Budgetary Authority and Coalition Management

10.1093/oso/9780198817208.003.0008 ◽

2018 ◽

Author(s):

Paul Chaisty ◽

Nic Cheeseman ◽

Timothy J. Power

Keyword(s):

Resource Dependence ◽

Economic Resources ◽

System Level ◽

Energy Prices ◽

Economic Crises ◽

Government Transparency ◽

Discretionary Spending ◽

The Cost ◽

Coalition Size

This chapter considers how presidents use their budget powers and the allocation of targeted discretionary spending to manage their coalitions. It considers the costs of budget tool deployment (in terms of time, controversy, and economic resources), and the factors that affect these costs: system-level factors (government transparency, federalism, personal-vote elections), coalition-level factors (coalition size, fragmentation, and heterogeneity), and conjunctural factors (economic crises and energy prices). It explores these factors with cases of budget tool deployment in Ukraine, Ecuador, and Russia. The Ecuadorean and Russian cases illustrate the divergent effects of resource dependence on the cost of budget tool dependence. Finally, it uses data from MP surveys to show the high value that legislators attribute to budget tools, and to illustrate how the composition of coalitions affects the costs that presidents are likely to face.

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Computer Use and Habitual Spinal Posture in Australian Adolescents

Public Health Reports ◽

10.1177/003335490712200511 ◽

2007 ◽

Vol 122 (5) ◽

pp. 634-643 ◽

Cited By ~ 25

Author(s):

Leon M. Straker ◽

Peter B. O'Sullivan ◽

Anne Smith ◽

Mark Perry

Keyword(s):

Standard Deviation ◽

Longitudinal Studies ◽

Musculoskeletal System ◽

Computer Use ◽

Lumbar Lordosis ◽

Health Concern ◽

Neck Flexion ◽

Spinal Posture ◽

Photographic Analysis ◽

Head Flexion

Objective. Computer use is common in adolescents, and there is evidence that adolescent spinal posture alters during computer use. However, it is unknown if computer use and habitual postures are associated. The objective of this study was to evaluate associations between adolescent computer use and habitual postures. Methods. Eight hundred eighty-four adolescents (408 females, 476 males, mean age, 14.0 years, standard deviation, 0.2) completed a questionnaire assessing weekly computer use. Habitual spinal posture was assessed by photographic analysis while standing and sitting. Results. Computer use was associated with adolescent habitual postures. In males, increased computer use was associated with increased head flexion and neck flexion. In females, increased computer use was associated with increased lumbar lordosis. Conclusions. The amount of weekly computer use was associated with changes in habitual spinal postures, and these depended on gender. These associations may result from temporary computer postures leading to adaptive neuromusculoskeletal changes, though further multivariate and longitudinal studies are needed to confirm causality. As some habitual posture changes may place a greater strain on the musculoskeletal system, computer use by adolescents should be viewed as a possible health concern.

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The Potential Impact of Utilizing Advanced Engine Technology for a Combat Capable Unmanned Air Vehicle (UAV)

Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery ◽

10.1115/2000-gt-0014 ◽

2000 ◽

Author(s):

Greg B. Bruening ◽

James R. Snyder ◽

Raymond E. Fredette

Keyword(s):

Life Cycle ◽

Performance Comparison ◽

Advanced Technology ◽

System Level ◽

Life Cycle Costs ◽

Air Defense ◽

Unmanned Air Vehicle ◽

Air Vehicle ◽

Potential Impact ◽

The Cost

This paper evaluates the potential impact of utilizing advanced engine technology for a limited life, combat capable, unmanned air vehicle (UAV) application. A study was conducted to define payoffs in terms of mission capability and system level life cycle costs (LCC) associated with implementing three different engine development approaches into a combat capable UAV design. The three different approaches considered were: a new, advanced technology engine; an existing (off-the-shelf) engine; and a derivative of an existing engine with limited technology insertion. A detailed vehicle configuration design was developed to conduct this assessment, including a low observable (LO), highly integrated engine/airframe layout for survivability and mission adaptable considerations. The vehicle is designed with multi-role mission capability such as suppression of enemy air defense (SEAD), close air support (CAS), and battlefield air interdiction (BAI). A system level performance comparison is assessed with the three different engine approaches, specifically for the SEAD-type mission. For the cost analysis, the multi-role mission capability is reflected in the overall assumptions such as in the number of aircraft needed to meet the mission requirements. A system level assessment such as in this study is essential in determining whether the additional costs associated with the development of a new, advanced engine is worth the investment. The results of this study suggest that advanced engine technology insertion can provide significant benefits in terms of mission range capability, vehicle weight/size, and overall life cycle costs versus an existing engine.

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Economic Burden and Clinical Impact of Opioid Dependence in Patients Undergoing Lower Extremity Bypass Surgery: Quantifying the Cost of a New Epidemic

Journal of Vascular Surgery ◽

10.1016/j.jvs.2019.01.006 ◽

2019 ◽

Vol 69 (3) ◽

pp. e27 ◽

Cited By ~ 1

Author(s):

Matthew Aizpuru ◽

Kevin X. Farley ◽

Lindsay K. Gallo ◽

Eric R. Wagner ◽

William D. Jordan ◽

...

Keyword(s):

Lower Extremity ◽

Economic Burden ◽

Opioid Dependence ◽

Bypass Surgery ◽

Clinical Impact ◽

The Cost

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The Effects of Force That Pushes Forward Lumbar Region on Sagittal Spinal Alignment When Wearing Backpack

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16193643 ◽

2019 ◽

Vol 16 (19) ◽

pp. 3643

Author(s):

Tae-sung In ◽

Seung-man Yu ◽

Sang-hun Jang

Keyword(s):

Lumbar Lordosis ◽

Sagittal Plane ◽

The State ◽

Sacral Slope ◽

Lumbar Region ◽

Spinal Alignment ◽

Inferior Angle ◽

Sagittal Spinal Alignment ◽

Lumbar Alignment ◽

Adult Volunteers

The purpose of this study is to design a backpack to push the lumbar region forward and confirm the change in the sagittal plane of the spine using radiography when wearing the backpack to present an effective backpack wearing method that can help spinal alignment. Place the question addressed in a broad context and highlight the purpose of the study. A total of 14 adult volunteers participated in the study. The study was carried out on the subjects without carrying a backpack, with a general backpack, and with a backpack designed to push the lumbar region forward. We investigated cervical, thoracic, lumbar, and sacral alignment under these three conditions. Lumbar lordosis showed a significant decrease in the state of wearing a general backpack compared to the case without a backpack, and a significant increase in the state of wearing a backpack designed to push the lumbar region forward rather than a general backpack. In addition, the sacral slope was significantly increased when carrying the backpack designed to push the lumbar region forward, compared to carrying the general backpack. There was a significant correlation between the sacral and lumbar alignment change when wearing the backpack compared to the state without a backpack. The results of this study indicate that wearing a backpack designed to push the lumbar region forward may contribute to the recovery of lumbar lordosis that is reduced when wearing a general backpack. This may be due to an increase in the sacral slope corresponding to the inferior angle of lumbar spine.

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Embedded Flexible Hybrid Electronics for the Internet of Things

International Symposium on Microelectronics ◽

10.4071/isom-2015-tp12 ◽

2015 ◽

Vol 2015 (1) ◽

pp. 000006-000013 ◽

Cited By ~ 2

Author(s):

Val R. Marinov

Keyword(s):

Internet Of Things ◽

Low Cost ◽

System Level ◽

Smart Devices ◽

The Internet ◽

Physical Form ◽

Pick And Place ◽

The Cost ◽

The Internet Of Things ◽

Generation Technology

The Internet of Things (IoT) “things” are often times described as active or smart devices and objects augmented with sensing, processing, and network capabilities. These smart objects are in the heart of the IoT concept but they alone cannot realize the full potential of IoT. The most ubiquitous objects in the IoT ecosystem, those that reside at the lowest system level and interact with the higher-level smart object, are based on the passive RFID technology. In the form of wireless passive sensors these objects are found in smart packaging, they form the backbone of the structural health monitoring systems, they provide non-invasive and continuous monitoring of physiological parameters, etc. RFID capability is already added to everyday items in the physical form of adhesive “smart” labels, enabling them to become “citizens” of the IoT ecosystem, but this “add-on“ approach increases the implementation cost and oftentimes impacts negatively the host item's form factor and appearance. It also does very little in terms of security and counterfeit prevention. On the other hand, the key economic factor that drives the deployment of the IoT is the cost at the end points. Therefore, the future of the IoT depends on developing an ultra-low-cost technology solution that can mass-produce low cost, RFID-enabled IoT objects on flexible substrates, ready for integration into everyday items. In some cases, such as in intelligent packaging, these objects will be non-obstructive and seamlessly integrated in their hosts. This integration will minimize the cost of implementation and will provide an insurmountable barrier to counterfeiters as they will need access to sophisticated and capital-intensive technologies in order to be able to alter or replicate the product's embedded configuration. Presented are two disruptive processes for packaging of ultrathin flexible hybrid electronic systems with ICs as thin as 15–20 μm and as small as 250 μm per side. The first generation technology is a modification of the conventional pick-and-place technique and has been already demonstrated on a commercial-grade roll-to-roll assembly line with packaging rates exceeding 10,000 cph. The second generation technology uses a laser beam to scan and transfer ultrathin, ultra-small ICs for high-precision assembly onto various flexible and rigid substrates. It provides packaging rates significantly exceeding those of the conventional pick-and-place equipment. Reported are also results from integrating the resulting ultrathin flexible hybrid electronic devices into thin materials such as paper and plastics.

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IP167. Patency at the Cost of Major Bleeding—the Dual-Antiplatelet Dilemma Following Lower Extremity Endovascular Intervention

Journal of Vascular Surgery ◽

10.1016/j.jvs.2016.03.121 ◽

2016 ◽

Vol 63 (6) ◽

pp. 106S-107S

Author(s):

Ryan M. Svoboda ◽

Carly Paterson ◽

Salman T. Hussain ◽

Nicole Curnes ◽

Robin Larson ◽

...

Keyword(s):

Lower Extremity ◽

Major Bleeding ◽

Endovascular Intervention ◽

The Cost

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Lower Extremity Extension Force and Electromyography Properties as a Function of Knee Angle and Their Relation to Joint Torques: Implications for Strength Diagnostics

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0b013e3181ddfce3 ◽

2011 ◽

Vol 25 (6) ◽

pp. 1622-1631 ◽

Cited By ~ 12

Author(s):

Daniel Hahn

Keyword(s):

Lower Extremity ◽

Knee Angle ◽

Joint Torques ◽

Extension Force

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Financial Impact of MRI in Treatment of Foot and Ankle Osteomyelitis

Foot & Ankle Orthopaedics ◽

10.1177/2473011417s000162 ◽

2017 ◽

Vol 2 (3) ◽

pp. 2473011417S0001

Author(s):

Srikanth Divi ◽

Kelly Hynes ◽

Douglas Dirschl ◽

Cody Lee

Keyword(s):

Lower Extremity ◽

Clinical Decision Making ◽

Tertiary Care ◽

The United States ◽

Operative Procedures ◽

Financial Impact ◽

Foot And Ankle ◽

Plain Radiographs ◽

Significant Difference ◽

The Cost

Category: Ankle, Diabetes, Hindfoot, Lesser Toes, Midfoot/Forefoot, Infection Introduction/Purpose: Osteomyelitis of the foot and ankle is a common condition with a high economic burden in the United States, particularly in the context of diabetes mellitus. The timely and accurate diagnosis of osteomyelitis is important to initiate treatment and possibly reduce overall healthcare costs. Plain radiographs are the initial study of choice given their widespread availability and low cost. Magnetic resonance imaging (MRI) is generally considered the most sensitive imaging modality for detecting osteomyelitis, however it is associated with significant cost and may not change overall treatment as compared to plain radiographs. The purpose of our retrospective study is to determine whether the use of MRI at our institution changed clinical decision making and calculate the financial impact in patients with foot and ankle osteomyelitis. Methods: We retrospectively identified patients at our tertiary care, academic center treated for a diagnosis of osteomyelitis using ICD-9 codes 730.07, 730.17, and 730.27. Demographic data including age, sex, race and ethnicity and patient comorbidities was collected. The use of plain radiographs, MRI, and any operative procedures up to 2 years after the index encounter for each patient were identified. An impact MRI was defined as an MRI that led to an operative procedure within the same admission encounter. The cost of an impact MRI was estimated using the equation: (average MRI cost)*(total MRIs/impact MRIs). Chi- squared test was used to statistically compare patients that underwent procedures in the MRI group vs. those in non-MRI group. Results: 619 patients undergoing osteomyelitis treatment between January 2009 and September 2015 at our institution were identified, of which 40.4% were female and 59.6% were male. 151 patients had a total of 227 MRIs of the lower extremity performed vs. 468 patients that did not have MRIs performed. Of the MRI cohort, 104/151 patients (68.9%) had subsequent operative procedures, whereas in the non-MRI cohort 299/468 patients (63.9%) had subsequent operative procedures (p = 0.26). Of the 227 MRIs performed, 85 were deemed impactful MRIs and 142 were deemed non-impactful MRIs. Average MRI cost at our institution for the lower extremity with and without contrast was $5069.75. Using our previous definition, the cost of an impact MRI was calculated to be effectively $13,539.21. Conclusion: MRI can be an effective modality in aiding the clinical diagnosis of osteomyelitis, however, it can be an unnecessary cost when not used to guide treatment. In our study, we did not find a significant difference in the operative rate between patients undergoing MRIs vs. those that did not. We also found that the effective cost of an MRI that led to a change in treatment was $13,539, almost 2.7 times higher than the average cost of an MRI at our institution.

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