Running Kinematics and Shock Absorption Do Not Change After Brief Exhaustive Running

2011 ◽  
Vol 25 (6) ◽  
pp. 1479-1485 ◽  
Author(s):  
John P Abt ◽  
Timothy C Sell ◽  
Yungchien Chu ◽  
Mita Lovalekar ◽  
Ray G Burdett ◽  
...  
Keyword(s):  
Shock Absorption

scholarly journals Application of Glass Fiber and Carbon Fiber-Reinforced Thermoplastics in Face Guards

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Takahiro Wada ◽  
Hiroshi Churei ◽  
Mako Yokose ◽  
Naohiko Iwasaki ◽  
Hidekazu Takahashi ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Impact Testing ◽  
Fiber Reinforced ◽  
Shock Absorption ◽  
Glass Fiber Reinforced ◽  
Field Of Vision ◽  
Commercial Glass ◽  
Carbon Fiber Reinforced ◽  
Reinforced Thermoplastics

Face guards (FGs) are protectors that allow for the rapid and safe return of athletes who are to play after sustaining traumatic facial injuries and orbital fractures. Current FGs require significant thickness to achieve sufficient shock absorption abilities. However, their weight and thickness render the FGs uncomfortable and reduce the field of vision of the athlete, thus hindering their performance. Therefore, thin and lightweight FGs are required. We fabricated FGs using commercial glass fiber-reinforced thermoplastic (GFRTP) and carbon fiber-reinforced thermoplastic (CFRTP) resins to achieve these requirements and investigated their shock absorption abilities through impact testing. The results showed that an FG composed of CFRTP is thinner and lighter than a conventional FG and has sufficient shock absorption ability. The fabrication method of an FG comprising CFRTP is similar to the conventional method. FGs composed of commercial FRTPs exhibit adequate shock absorption abilities and are thinner and lower in weight as compared to conventional FGs.

The Comparative Analysis of Cushion or Shock Absorption Characteristic of Commonly-Used Cushion Packaging Materials

2012 ◽  
Vol 490-495 ◽  
pp. 3902-3906 ◽  
Author(s):  
Zhen Jie Du ◽  
Wan Yu Gao ◽  
Hai Hong Kang ◽  
Sheng Jun Liu ◽  
Ming Xi Hu ◽  
...  
Keyword(s):  
Dynamic Compression ◽  
Static Stress ◽  
Final Conclusion ◽  
Absorption Characteristic ◽  
Packaging Materials ◽  
Shock Absorption ◽  
Static Test ◽  
Reference Information ◽  
Stress Curve ◽  
Packaging Structure

The purpose and method of this paper is to comparatively analyze several commonly-used cushion packaging materials, obtain their shock absorption characteristic curves, and by doing such, provide reference information for cushion packaging design and research. With the static test, dynamic compression test and vibration transfer test carried out, the cushion coefficient ~ static stress curve, maximal acceleration ~ static stress curve and vibration transfer rate ~ frequency curve are gained. A final conclusion is educed that in practical design routine, rational choice of cushion packaging materials, scientific design of packaging structure and validation of anti-vibration capability are relative to those three curves.

Significance of Heel Pad Confinement for the Shock Absorption at Heel Strike

1988 ◽  
Vol 09 (06) ◽  
pp. 468-473 ◽  
Author(s):  
U. Jørgensen ◽  
J. Ekstrand
Keyword(s):  
Heel Strike ◽  
Shock Absorption ◽  
Heel Pad

Functional Evaluation of a Personalized Orthosis for Knee Osteoarthritis - A Motion Capture Analysis

2021 ◽  
Author(s):  
Martin Huber ◽  
Matthew Eschbach ◽  
Kazem Kazerounian ◽  
Horea T. Ilies
Keyword(s):  
Knee Joint ◽  
Knee Osteoarthritis ◽  
Motion Capture ◽  
Inverse Dynamics ◽  
Statistical Significance ◽  
Knee Kinematics ◽  
Contact Forces ◽  
Patient Specific ◽  
Functional Evaluation ◽  
Shock Absorption

Abstract Knee osteoarthritis (OA) is a disease that compromises the cartilage inside the knee joint, resulting in pain and impaired mobility. Bracing is a common treatment, however currently prescribed braces cannot treat bicompartmental knee OA, fail to consider the muscle weakness that typically accompanies the disease, and utilize hinges that restrict the knee's natural biomechanics. We have developed and evaluated a brace which addresses these shortcomings. This process has respected three principal design goals: reducing the load experienced across the entire knee joint, generating a supportive moment to aid the muscles in shock absorption, and interfering minimally with gait kinematics. Load reduction is achieved via the compression of medial and lateral leaf springs, and magnetorheological dampers provide the supportive moment during knee loading. A novel, personalized joint mechanism replaces a traditional hinge to reduce interference with knee kinematics. Using motion capture gait analysis, we evaluated the basic functionality of a prototype device. We calculated, via inverse dynamics analysis, the reaction forces at the knee joint and the moments generated by the leg muscles during gait. Comparing these values between braced and unbraced trials allowed us to evaluate the system's effectiveness. Kinematic measurements showed the extent to which the brace interfered with natural gait characteristics. Of the three design goals: a reduction in knee contact forces was demonstrated; increased shock absorption was observed, but not to statistical significance; and natural gait was largely preserved. The techniques presented in this paper could lead to improved OA treatment through patient-specific braces.

scholarly journals Age-related changes in shock absorption capacity of the human spinal column

2018 ◽  
Vol Volume 13 ◽  
pp. 987-993
Author(s):  
Grażyna Brzuszkiewicz-Kuźmicka ◽  
Jan Szczegielniak ◽  
Dawid Bączkowicz
Keyword(s):  
Spinal Column ◽  
Absorption Capacity ◽  
Shock Absorption ◽  
Age Related ◽  
Age Related Changes

scholarly journals Study of Physical Properties and Shock Absorption Abilities of Starch Polymer Foam as Cushioning Material for Packaging

2018 ◽  
Vol 225 ◽  
pp. 06010
Author(s):  
N. Amir ◽  
Mohamed Syakir Mohamed Hisham ◽  
Kamal Ariff Zainal Abidin
Keyword(s):  
Average Density ◽  
Curing Process ◽  
Polymer Foam ◽  
Shock Absorption ◽  
Open Cell ◽  
Lack Of Information ◽  
Closed Cell ◽  
Open Cell Foam ◽  
Cell Foam ◽  
Cushioning Material

Lack of information about the formulation and fabrication process of starch polymer foam and lack of study in the shock absorption ability of starch polymer foam were the reasons this research was executed. In this project starch polymer foam was produced to be used as cushioning material for packaging. Starch polymer foam were developed from starch, polyvinyl alcohol (PVA), urea, citric acid, and deionised water. Water amount with drying and curing process were the variables manipulated to produce the best starch polymer foam. It was determined then, that the optimized ratio of starch:PVA:citric acid was 1:1:4. The amount of water used was 10 ml/gram of starch/PVA weight. The suitable foaming mixing was done at a speed of 1500 rpm for 40 minutes. Drying process was done at 70°C for 24 hours, followed by curing process at 100°C for 1 hour to produce closed-cell foam. While for the open-cell foam, the foam was dried and cured at 100ºC for 6 hours. The open-cell and closed-cell foams produced were cut to 6 cm height x 6 cm width x 0.5 cm thick. The average density was calculated and then the foams were subjected to weight drop destructive test. The test was done by placing a foam on top of a piece of mirror, and a weight is dropped onto the foam, with increasing height until the mirror break. Three weights were used with mass of 50 g, 100 g and 200 g. The starch foams were compared to polyurethane and polystyrene foams in terms of the minimum height that can cause the mirror to break. The results showed that starch closed-cell foam absorbed the highest impact energy followed by polystyrene foam, starch open-cell foam and polyurethane foam.

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