The Development of Military Helmet for Bare-Handed Combat

Author(s):  
Xiaobin Yang
Keyword(s):  
2020 ◽  
Vol 22 (Supplement_N) ◽  
pp. N131-N131
Author(s):  
Massimo Bolognesi

Abstract The Pickelhaube Sign is today recognized as a novel Echocardiographic Risk Marker for Malignant Mitral Valve Prolapse Syndrome. Mitral Valve Prolapse (MVP) has long been recognized to be a relatively common valve abnormality in the general population. Patients with relatively non-specific symptoms and asymptomatic athletes who have MVP still represent an important clinical conundrum for any physician involved in preventive medicine and sports screening. Although cardiac arrhythmias and/or cardiac death are an undesirable problem in MVP patients, when these subjects were studied with Holter Electrocardiogram (ECG) monitoring a prevalence of ventricular arrhythmias up to 34% was observed, with premature ventricular contractions as the most common pattern (66% of cases). At this regard a paper by Anders et al. described a series of cases that suggest that even clinically considered benign cases of MVP in young adults may cause sudden and unexpected death. However, cardiac arrest and Sudden Arrhythmic Cardiac Death (SCD) resulted in rare events only in patients with MVP based on data from a community study. A middle-aged athletic male who has been practicing competitive cycling for about 20 years came to our Sports Medicine Centre to undergo screening of sports preparation for competitive cycling and the related renewal of certification for participation in sports competitions. This athlete was always considered suitable in previous competitive fitness assessments performed in other sports medicine centers. His family history was unremarkable, as well as his recent and remote pathological anamnesis. The physical examination revealed a 3/6 regurgitation heart murmur with a click in the mid late systole. Previous echocardiographic examinations revealed a MVP which was considered benign with mild not relevant mitral regurgitation. He did not complain of symptoms such as dyspnoea or heart palpitations during physical activity. The resting ECG showed negative T waves in the inferior limb leads, and the stress test showed sporadic premature ventricular beats (a couple) with right bundle branch block morphology. An echocardiogram confirmed the presence of a classic mitral valve prolapse with billowing of both mitral leaflets, associated with a mild to moderate valve regurgitation. The TDI exam at the level of the lateral mitral annulus showed a high-velocity mid-systolic spike like a Pickelhaube sign, i.e. spiked German military helmet morphology. Consequently, an in-depth diagnostic imaging with cardiac magnetic resonance imaging was proposed, but the athlete refused it, both because he was totally asymptomatic and above all because he would be forced to pay a considerable amount of money as the examination is not guaranteed by the Italian National Health Service. In conclusion, the athlete remained sub judice as for competitive suitability, Finally, the question is: does MVP really cause sudden death? Is it enough to detect the Pickelhaube signal by echocardiography to stop this athlete? Let us bear in mind that this athlete was asymptomatic, and he had not had any trouble during exercise and maximal effort for many years. Why must we declare him unsuitable to do competitive sports?


Author(s):  
Timothy G. Zhang ◽  
A. H. Fulton ◽  
K. Ravi-Chandar ◽  
Sikhanda S. Satapathy

Abstract Foam pads are commonly used in sports and military helmet for energy absorption, form-fitting and comfort. Both for low velocity and high velocity applications, their rate-dependent mechanical properties need to be characterized to understand their ability to effectively modulate the transmitted stress pulse. Impact experiments were conducted on bilayer helmet pads at a range of velocities covering low to medium rates up to ∼7000/s. Images from high-speed camera were used to construct x-T diagrams to measure the shock speeds from the impact experiments. Numerical simulations were carried out to validate a foam pad model and to understand experimental uncertainties. The scatter in the measured shock speeds was found to be related to the scatter in the material properties.


Author(s):  
Kimberly B. Vasquez ◽  
Katie P. Logsdon ◽  
Daniel B. Dorman ◽  
Valeta Carol Chancey

Observed head injury has historically been mechanically related to headform center of gravity (CG) acceleration. Helmets (motorcycle, sports, military, etc.) are evaluated based on the headform CG peak acceleration for blunt impacts. However, recent interest has shifted to collecting data from the helmet shell itself, as it is an optimal location for mounting sensors due to ease of access, sufficient surface area availability, and limited interference to the wearer. In order to accurately predict head injury from data collected on the helmet shell, the helmet and headform must be rigidly coupled. Headform-helmet fit typically is dependent on the pad fitting system and the person mounting the helmet to the headform because a standard states which headform to use. The objective of this study is to compare the Department of Transportation (DOT) headform (currently used in military blunt impact testing) to the more anthropomorphic International Standard Organization (ISO) half headform. Testing was completed on a monorail drop tower to analyze the effect of helmet/headform coupling on the blunt impact behavior of ACH helmets using FMVSS test methodology. Three headform configurations were used: the DOT headform (standard for military helmet blunt impact testing) with required surrogate chin, the ISO half headform (standard for ASTM helmet testing), and the ISO half headform with a surrogate chin. The two currently field-approved pad types were also used to determine best headform-helmet fit. Results from these series of tests will be presented, including headform peak acceleration and relative motion between the helmet and headform.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 632-638
Author(s):  
Hoon Choi ◽  
Vicky Varghese ◽  
Jamie Baisden ◽  
Diane W Braza ◽  
Anjishnu Banerjee ◽  
...  

ABSTRACT Introduction Addition of head-supported mass imparts greater demand on the human neck to maintain functionality. The same head-supported mass induces greater demand on the female spine than the male spine because female necks are comparatively slender. Prevalence of neck pain is greater in military than civilian population because of the head-borne mass (among other factors). The goal of this study is to determine quantifiable parameters related to muscle geometry using female human volunteers and upright magnetic resonance imaging. Materials and Methods Young healthy subjects were consented. Demographics and head–neck anthropometry were recorded. For all the 7 subjects, the T1- and T2-weighted magnetic resonance imaging in the neutral sitting position was obtained immediately following donning and after 4 hours of continuous wear of standard issued military helmet, while seated in the same posture for 4 hours. Cross-sectional areas of sternocleidomastoid and multifidus muscles from C2-C7, overall and segmental Cobb angles (C2-T1), and centroid and radius of each muscle were calculated. Data were compared with determine differences with the continuous helmet wear. Results There were level specific changes in morphological parameters for each of the muscles. Significant difference (P < 0.05) in cross-sectional areas was noted at C2-3 level for sternocleidomastoid and at C3-4 and C5-6 levels for multifidus. For centroid angles, significant difference (P < 0.05) was observed at C2-3 and C5-6 levels for sternocleidomastoid and at C3-4 level for multifidus. There was no significant difference (P > 0.05) in muscle centroid radii between the pre- and posttest conditions. Conclusions Alterations in muscle geometries were muscle specific and level specific: sternocleidomastoid was significant at the upper level, whereas multifidus was significant at the mid-lower cervical spine segments. The insignificant difference in the Cobb angles was attributed to length of time of continuous helmet wear attributed and sample size. Helmet wear can lead to morphometric alterations in cervical flexor/extensor musculature in females.


2017 ◽  
Vol 16 (1) ◽  
pp. 183-183
Author(s):  
Z. Rahmani ◽  
A. Kochanek ◽  
J.J. Astrup ◽  
J.N. Poulsen ◽  
P. Gazerani

Abstract Aims Headache is a leading reason to seek medical care. Several subtypes of headaches have been defined, one of which is external compression headache. This headache is due to an external physical compression applied on the head. It affects approximately 4% of the general population; however, certain populations for example construction workers and military personnel with particular needs of headwear or helmet are at higher risk for development of this type of headache. Generally, external compression headache is poorly studied and there is no report on helmet-induced headache among Danish military personnel. This survey-based study was designed to investigate prevalence and pattern of helmet-induced external compression headache among these personnel. Methods Questionnaires were carefully developed and delivered to a total of 279 participants who use helmets in the Danish military service. The military of the Northern Jutland region of Denmark facilitated recruitment of study participants. Questionnaires were delivered on paper and anonymous answers were collected and used for further analysis. Data were handled using descriptive statistics. Results Up to 30% of the participants reported headache in relation to wearing the military helmet. Headache was defined as moderate intensity with pressing pain quality mostly located in front of the head. Two types of helmets in this study were different in the weight and padding of the inner part and delivered different pattern of pressure; while one evenly delivered pressure on multiple head regions, the other delivered pressure mostly on the sides and top of the head. This suggests that helmet pressure and headache location might be associated. Conclusions This study was first to demonstrate prevalence and pattern of helmet-induced headache among military personnel in North Jutland, Denmark. Findings of this study call for further attention to helmet-induced headache and strategies to minimize the burden, for example by design of appropriate helmets.


2019 ◽  
Vol 166 (5) ◽  
pp. 342-346
Author(s):  
Debra J Carr ◽  
E Lewis ◽  
PF Mahoney

The aim of this paper was to provide the military medical community with an expert summary of military helmets used by HM Armed Forces. The design of military helmets and test methods used to determine the fragmentation and non-ballistic impact protection are discussed. The helmets considered are Parachutist, Combat Vehicle Crewman, Mk6, Mk6A, Mk7 and VIRTUS. The helmets considered provide different levels of fragmentation and non-ballistic impact protection dictated by the materials available at the time of the helmet design and the end-user requirement. The UK Ministry of Defence defines the area of coverage of military helmets by considering external anatomical features to provide protection to the brain and the majority of the brainstem. Established test methods exist to assess the performance of the helmet with respect to the threats; however, these test methods do not typically consider anatomical vulnerability.


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