Is Sitting on a Wallet a Big Deal? Or Causing My Glute or Low Back Pain?
To sit on a wallet or not to sit on a wallet, that is the question.
Many of us walk around everyday with our wallet in our back pocket, we go on to drive with it in our back pocket, sit on it for hours at work, and at the end of the day might even relax with it in our back pocket while we enjoy a wind-down at the end of the day on the couch or another favorite chair.
While the majority of us won’t get discomfort or pain from sitting on a wallet some of us will. In this blog we’re going to discuss what the research says about what happens to the lumbar spine(our lower back) and our pelvis when we sit on a wallet and why some individuals develop pain when sitting on a wallet.
1978. Credit-Card Wallet Sciatica
The first article I was able to find on wallet induced pain was a letter-to the editor in an 1978 Journal of American Medical Association and it discussed how three patients were all experiencing similar symptoms pain in the glute/buttock region with no “known cause”. However, after further investigation it was realized that the individuals were sitting on quite thick wallets, 37 millimeters thick and 28 millimeters thick. A deck of cards is about 20 millimeters thick so these were quite thick wallets. After moving the wallet to a different location and no longer sitting on it the symptoms went a way and the individuals ended up having no pain.
Sitting on a Wallet Causing Pain?
In this blog, we will explore the effects of sitting on a wallet, focusing on a recent study examining changes in the position and orientation of the pelvis and lumbar spine, as well as increased pain at the site of the wallet. We will also discuss how sitting on a wallet can lead to compression neuropathy of the sciatic nerve and if occurring over a long period of time has the potential to lead to central sensitization.
The Study: Effects of Sitting on a Wallet
The study involved 24 participants (12 males and 12 females) who sat for 15 minutes each on four different wallet thicknesses (0, 12, 22, and 32 mm). Researchers measured trunk kinematics, seat pan pressure distribution, and discomfort for each thickness.
The findings revealed that sitting on wallets 22 mm thick and above caused significant changes in the position and orientation of the pelvis and lumbar spine. Specifically, there was an increase in pelvic posterior rotation, pelvic left lateral bending, thoracic flexion, and thoracic right lateral bending compared to the no-wallet condition. Additionally, the pain at the site of the wallet increased as wallet thickness increased. It is also worth noting that although males and females showed differences in the magnitude of lateral bend angles at all spine levels, both genders demonstrated the same directions of postural compensation.
However, this study has its limitations. The small sample size and short duration of exposure to wallet thicknesses may not fully represent the effects of sitting on a wallet for longer periods and on a more diverse population but in the end sitting on a wallet does change the position of the spine and pelvis. However, pain was primarily at the location where the wallet was.
What sitting on a wallet does to the tissues being compressed.
Wallet-Induced Compression Neuropathy
Sitting on a wallet can cause an entrapment or compression neuropathy of the sciatic nerve. This occurs when the pressure from the wallet compresses the nerve, leading to inflammation, irritation, and potentially damage. Over time, this compression can result in pain, numbness, and weakness in the affected areas.
When you sit on a wallet, the pressure it exerts on the soft tissues and underlying nerves can lead to compression neuropathy. In the case of wallet-induced compression neuropathy, the sciatic nerve is particularly vulnerable. The sciatic nerve is the longest and widest nerve in the human body, running from the lower back through the buttocks and down the legs. Compression of this nerve can lead to a range of symptoms and physiological changes:
Inflammation: As the nerve is compressed, it becomes irritated and inflamed. Inflammation is a natural response to injury and serves to protect the affected area. However, persistent inflammation due to ongoing compression can exacerbate the problem and cause further damage to the nerve.
Impaired nerve function: Compression of the nerve can disrupt the normal functioning of nerve fibers. This can lead to altered sensations, such as numbness or tingling, as well as muscle weakness in the affected areas. Over time, this impaired nerve function can impact daily activities and overall quality of life.
Ischemia: Prolonged compression can also reduce blood flow to the nerve, causing ischemia. Ischemia is a condition in which tissues receive insufficient oxygen and nutrients due to inadequate blood supply. This lack of oxygen and nutrients can lead to nerve damage and further exacerbate the symptoms of compression neuropathy.
Wallerian degeneration: In severe cases, prolonged compression can result in Wallerian degeneration, a process in which the nerve fibers break down and degenerate. This degeneration can lead to irreversible damage to the nerve and potentially result in chronic pain and disability.
Pain: As a result of these physiological changes, individuals experiencing wallet-induced compression neuropathy may experience localized pain in the gluteal area or radiating pain down the leg, depending on the specific location and severity of the compression.
While many people don’t have discomfort from sitting on a wallet to minimize the risk of wallet-induced compression neuropathy, it is best to avoid sitting on your wallet and to address any symptoms promptly.
What can possibly happen in longer term compression?
Chronic Peripheral Nerve Compression and Central Sensitization
Chronic peripheral nerve compression, such as that experienced when sitting on a wallet, can lead to central sensitization. Central sensitization is a condition in which the nervous system becomes more sensitive to stimuli, resulting in increased pain perception. When a peripheral nerve is chronically compressed, it can become irritated and inflamed, sending persistent pain signals to the central nervous system. Over time, this can result in heightened sensitivity and pain in the affected area, even when the initial cause of the compression is removed.
It is important to note that central sensitization usually occurs after a prolonged period of nerve compression. Research has shown that persistent pain lasting more than three months can lead to central sensitization, although individual experiences may vary. So again this reiterates the point that if you remove the wallet before pain starts to occur it is most likely sitting on a wallet won’t have long term effects because you removed the wallet and the potential for injury
Please just remove the wallet.
Practical Implications and Recommendations
While the research has looked at wallet thickness of various sizes, 9mm-32 millimeters and pain was only seen in the groups with wallets 22 millimeters or more, I highly suggest removing the wallet from the back pocket anyways. There hasn’t been a ton of research on the effects of sitting on a wallet but we do know the pain increases as the wallet gets thicker. We also know that a large portion of the American work force sits for over 50% of their day. 50% of your day sitting on a wallet 5 days a week for 45+ weeks a year is a lot of time. We know that long term direct pressure on nerves can lead to an increase in inflammation, sensitization of the nerve, and pain, and we know that most individuals can experience relief and an improvement of symptoms by simply removing the wallet from their back pocket while sitting.
Thanks for Reading
While the study we discussed has its limitations, it provides valuable insights into the potential consequences of sitting on a wallet. As we spend more time sitting in our daily lives, it's crucial to be mindful of our sitting habits and take necessary actions to avoid potential discomfort and long-term effects. I hope you enjoyed this blog and we’ll continue exploring different research on pain and a lot more in the future.
References
Daniel Viggiani, Mamiko Noguchi, Kristina M. Gruevski, Diana De Carvalho & Jack P. Callaghan (2014) The Effect of Wallet Thickness on Spine Posture, Seat Interface Pressure, and Perceived Discomfort During Sitting, IIE Transactions on Occupational Ergonomics and Human Factors, 2:2, 83-93, DOI: 10.1080/21577323.2014.962712
Rempel DM, Diao E. Entrapment neuropathies: pathophysiology and pathogenesis. J Electromyogr Kinesiol. 2004 Feb;14(1):71-5. doi: 10.1016/j.jelekin.2003.09.009. PMID: 14759752.
Siddiq MAB, Jahan I, Masihuzzaman S. Wallet Neuritis - An Example of Peripheral Sensitization. Curr Rheumatol Rev. 2018;14(3):279-283. doi: 10.2174/1573397113666170310100851. PMID: 28294069; PMCID: PMC6204659.
Siddiq MAB. Piriformis Syndrome and Wallet Neuritis: Are They the Same? Cureus. 2018 May 10;10(5):e2606. doi: 10.7759/cureus.2606. PMID: 30013870; PMCID: PMC6039217.