Electromagnetic shielding and phantom pain [tech corner]

Electromagnetic interference or EMI is supposed to contribute to phantom pain; also the term electromagnetic fields (EMF) is used. We do not know why that would be. Other theories attribute phantom pains to an efference/afference dysbalance. Apparently, mirror therapy works but not in all cases. Really, the only pathophysiologically sensible explanation from my personal ex

But, what do we know.

What we know is that both FARABLOC and UMBRELLAN or "Stumpfstrumpf Relax Night Care" are metal mesh stump socks that are sold for a lot of money.

Apparently some studies "confirm" that "they work".

The basis for their function is according to the untested sales claim that they "shield" EMI / EMF. On the FARABLOC website, they state that "Farabloc is a cloth like material that has been tested and proven to provide high EMF protection when wrapped or placed on the area of injury"; some research covering FARABLOC also found that it works against sore muscles which hints at the possibility that warmth (heat loss insulation) could be at work; given my stump always being colder due to poor circulation it is a fact that I may benefit from wearing a wool or cotton sock over it (of course not an overpriced metal mesh), or more likely, compression [link]. UMBRELLAN is advertised with "Umbrellan® is a unique, patented knitted fabric that combines with an excellent electromagnetic screen" and "Das patentierte Umbrellan kann elektromagnetische Strahlungen aus der Umwelt abschirmen".


That, however, does not seem plausible. Either the shielding material may have to be at least ~3 mm thick and made of a suitable substance such as copper and contains no holes (i.e., also no hole for the arm). Or, the metallic cover may have to be grounded.

Any un-grounded thin metallic cover - think "tin foil hat" - may more likely act as an antenna than as a deflector. That means, that by wearing a metallic mesh fabric without proper grounding, you will likely not deflect any substantial amounts of electromagnetic interference.

Tinfoil hats come to mind that "use" the same "design" as these allegedly phantom pain-reducing metal mesh socks. Also, tin foil hats (if not properly grounded or built) will more likely act as an antenna - which however has been scientifically shown (below).

In fact, one double-blinded study showed that aluminum foils used to wrap stumps did not effect phantom limb pain at all [1] 1.


From (link):

In 2005, a group of MIT students, prodded by "a desire to play with some expensive equipment," tested the effectiveness of foil helmets at blocking various radio frequencies. Using two layers of Reynolds aluminum foil, they constructed three helmet designs, dubbed the Classical, the Fez, and the Centurion, and then looked at the strength of the transmissions between a radio-frequency signal generator and a receiver antenna placed on various parts of their subjects' bare and helmet-covered heads.

The helmets (..) surprisingly, amplified certain frequencies: those in the 2.6 Ghz ( allocated for mobile communications and broadcast satellites) and 1.2 Ghz (allocated for aeronautical radionavigation and space-to-Earth and space-to-space satellites) bands.


While the underlying concept is good, the typical foil helmet fails in design and execution. An effective Faraday cage fully encloses whatever it's shielding, but a helmet that doesn't fully cover the head doesn't fully protect it. If the helmet is designed or worn with a loose fit, radiofrequency electromagnetic radiation can still get up underneath the brim from below and reveal your innermost thoughts to the reptilian humanoids or the Bilderberg Group.

From (link):

On the Effectiveness of Aluminium Foil Helmets: An Empirical Study

Ali Rahimi 1, Ben Recht 2, Jason Taylor 2, Noah Vawter 2 - 17 Feb 2005

1: Electrical Engineering and Computer Science department, MIT.
2: Media Laboratory, MIT.


Among a fringe community of paranoids, aluminum helmets serve as the protective measure of choice against invasive radio signals. We investigate the efficacy of three aluminum helmet designs on a sample group of four individuals. Using a $250,000 network analyser, we find that although on average all helmets attenuate invasive radio frequencies in either directions (either emanating from an outside source, or emanating from the cranium of the subject), certain frequencies are in fact greatly amplified.

These amplified frequencies coincide with radio bands reserved for government use according to the Federal Communication Commission (FCC). Statistical evidence suggests the use of helmets may in fact enhance the government's invasive abilities. We speculate that the government may in fact have started the helmet craze for this reason.


It has long been suspected that the government has been using satellites to read and control the minds of certain citizens. The use of aluminum helmets has been a common guerrilla tactic against the government's invasive tactics [1]. Surprisingly, these helmets can in fact help the government spy on citizens by amplifying certain key frequency ranges reserved for government use. In addition, none of the three helmets we analyzed provided significant attenuation to most frequency bands. We describe our experimental setup, report our results, and conclude with a few design guidelines for constructing more effective helmets.

Experimental Setup

The three helmet types tested: The Classical, The Fez, The Centurion. We evaluated the performance of three different helmet designs, commonly referred to as the Classical, the Fez, and the Centurion. These designs are portrayed in Figure 1. 

Fig. : 

The Centurion:


The Fez:


The Classical:


The helmets were made of Reynolds aluminium foil. As per best practices, all three designs were constructed with the double layering technique described elsewhere [2]. A radio-frequency test signal sweeping the ranges from 10 Khz to 3 Ghz was generated using an omnidirectional antenna attached to the Agilent 8714ET's signal generator. The experimental apparatus, including a data recording laptop, a $250,000 network analyser, and antennae. A network analyser (Agilent 8714ET) and a directional antenna measured and plotted the signals. See Figure 2. Because of the cost of the equipment (about $250,000), and the limited time for which we had access to these devices, the subjects and experimenters performed a few dry runs before the actual experiment (see Figure 3). The receiver antenna was placed at various places on the cranium of 4 different subjects: the frontal, occipital and parietal lobes. Once with the helmet off and once with the helmet on. The network analyzer plotted the attenuation between the signals in these two settings at different frequencies, from 10Khz to 3 Ghz. Figure 4 shows a typical plot of the attenuation at different frequencies.

Fig. 4:



For all helmets, we noticed a 30 db amplification at 2.6 Ghz and a 20 db amplification at 1.2 Ghz, regardless of the position of the antenna on the cranium. In addition, all helmets exhibited a marked 20 db attenuation at around 1.5 Ghz, with no significant attenuation beyond 10 db anywhere else.


The helmets amplify frequency bands that coincide with those allocated to the US government between 1.2 Ghz and 1.4 Ghz. According to the FCC, These bands are supposedly reserved for ''radio location'' (ie, GPS), and other communications with satellites (see, for example, [3]). The 2.6 Ghz band coincides with mobile phone technology. Though not affiliated by government, these bands are at the hands of multinational corporations. It requires no stretch of the imagination to conclude that the current helmet craze is likely to have been propagated by the Government, possibly with the involvement of the FCC. We hope this report will encourage the paranoid community to develop improved helmet designs to avoid falling prey to these shortcomings.


The authors would like to thank Andy (Xu) Sun of the MIT Media Lab for helping with the equipment, Professor George Sergiadis for lending us the antennae, and Professor Neil Gershenfeld for allowing us the use of his lab equipment. (Please direct any queries to the authors, NOT these folks)

[1] R. C. Minnee, J. Bosma, K. Y. Lam, W. Wisselink, and A. C. Vahl, "Aluminium foil for the prevention of post-amputation pain: a randomised, double-blinded, placebo-controlled, crossover trial," British journal of pain, vol. 7, iss. 2, pp. 95-100, 2013.
  title={Aluminium foil for the prevention of post-amputation pain: a randomised, double-blinded, placebo-controlled, crossover trial},
  author={Minnee, Robert C and Bosma, Jan and Lam, Kayan Y and Wisselink, Willem and Vahl, Anco C},
  journal={British journal of pain},
  publisher={SAGE Publications Sage UK: London, England}


  1. Aluminium foil for the prevention of post-amputation pain: a randomised, double-blinded, placebo-controlled, crossover trial - Robert C Minnee, Jan Bosma, Kayan Y Lam, Willem Wisselink and Anco C Vahl - First Published April 22, 2013 - https://doi.org/10.1177/2049463713485727 -
    Abstract - Introduction: Phantom limb pain (PLP) is a painful sensation perceived in the missing limb after amputation. The underlying pathophysiology remains unclear. Until recently, only opioid analgesics have been proven to be effective in prospective studies. Anecdotally, patients with PLP employ self-help measures, sometimes including ‘wrapping up’ or rubbing their stump with aluminium foil for relief. Our hypothesis is that wrapping an amputation stump with aluminium foil perioperatively will prevent PLP in the postoperative period. -- Methods: From September 2007 to September 2009, 32 consecutive patients were included in a crossover, double-blinded, randomised clinical trial. Perioperative fitting of an aluminium stump bandage was compared with a placebo paper foil. Scores were noted daily in a variable diary. The observation period was 2 weeks: in the first week participants were double blinded, and in the second week there was a change of bandage from aluminium to placebo or vice versa. A visual analogue scale (VAS) score was used as primary research variable. Secondary variables were use of analgesics, VAS measures of wound pain and the incidence of wound infections. Statistical analysis was done by means of Student’s t-test for non-paired observations. -- Results: Baseline characteristics were similar between groups. A period effect (p= 0.84) and treatment–period interaction (p = 0.79) were not present. There was no significant difference (mean difference 0.42) between both treatments in PLP VAS scores (95% CI −2.56 to −1.81, p = 0.71). VAS measure of wound pain showed no significant difference between both groups (mean difference 0.34, 95% CI −2.32 to −1.66, p = 0.72). Also, the other secondary endpoints did not differ. -- Conclusion: Patients receiving an aluminium foil stump wrapping do not experience less phantom pain than with a placebo.

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - Electromagnetic shielding and phantom pain [tech corner]; published 23/05/2016, 19:57; URL: https://www.swisswuff.ch/tech/?p=5981.

BibTeX: @MISC{schweitzer_wolf_1624075986, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - Electromagnetic shielding and phantom pain [tech corner]}}, month = {May},year = {2016}, url = {https://www.swisswuff.ch/tech/?p=5981}}