In Search of Necessary Mouthguard Thickness. Part 1: From the Viewpoint of Shock Absorption Ability

2008 ◽  
Vol 52 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Masahiko Maeda ◽  
Tomotaka Takeda ◽  
Kazunori Nakajima ◽  
Mami Shibusawa ◽  
Katuhide Kurokawa ◽  
...  
Keyword(s):  
Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Takahiro Wada ◽  
Hiroshi Churei ◽  
Mako Yokose ◽  
Naohiko Iwasaki ◽  
Hidekazu Takahashi ◽  
...  

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.


2012 ◽  
Vol 490-495 ◽  
pp. 3902-3906 ◽  
Author(s):  
Zhen Jie Du ◽  
Wan Yu Gao ◽  
Hai Hong Kang ◽  
Sheng Jun Liu ◽  
Ming Xi Hu ◽  
...  

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.


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

1988 ◽  
Vol 09 (06) ◽  
pp. 468-473 ◽  
Author(s):  
U. Jørgensen ◽  
J. Ekstrand

2021 ◽  
Author(s):  
Martin Huber ◽  
Matthew Eschbach ◽  
Kazem Kazerounian ◽  
Horea T. Ilies

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.


2018 ◽  
Vol Volume 13 ◽  
pp. 987-993
Author(s):  
Grażyna Brzuszkiewicz-Kuźmicka ◽  
Jan Szczegielniak ◽  
Dawid Bączkowicz

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