Carpal Tunnel Syndrome (CTS) is a condition caused by compression of the median nerve in the wrist, as it passes through the carpal tunnel into the hand. Compression can occur if the tissues inside the tunnel become swollen or the tunnel narrows over time. As such, risk factors involve strenuous grip, repetitive wrist flexion and exposure to vibration, although medical literature is critical of an association between vibration and CTS in the absence of hand-arm vibration syndrome (HAVS).
(Source: Wikimedia Commons)
CTS is more common in females than in males, perhaps because female carpal tunnels are narrower, on average.
In a 2006 Command Paper, the Industrial Injuries Advice Council (IIAC) stated that CTS, ‘arising out of repeated palmar flexion and dorsiflexion of the wrist for at least 20 hours per week, for at least 12 months in aggregate in the 24 months prior to onset of symptoms’, can constitute a prescribed disease.
This month, Ja Heon Lee, the South Korean designer, has published blueprints of an ergonomically enhanced wireless hoover. The theory behind this design is that the body of the Lofstrand Vacuum Cleaner rests above the user’s forearm, thereby relieving strain in and around the carpal tunnel.
Figure: Lofstrand Vacuum Cleaner, by Ja Heon Lee
Are work-related upper limb diseases (WRULD), such as CTS, associated with the cleaning profession?
In 1995, researchers found a statistically significant association between cleaners and injuries to the wrist and forearms. Out of 221 female cases of wrist and forearm injury, 32 were cleaners and their risk of injury was 1.8 times greater than the control group.
Elsewhere, in an investigation of 99 female hospital cleaners, published in 2003, CTS was deemed to be ‘a disease related with the cleaning workers’. Incidence of the condition was more common in those who undertook hospital cleaning activities than in the general female population.
What about industrial vacuuming as a specific risk factor for WRULD?
2 separate studies, published in 2012, considered this question.
In the course of the 1st study, researchers at the University of New South Wales assessed the risk of WRULD in 24 cleaning workers in the normal course of their employment in government schools, hospitality and commercial office space sectors. Although the risk was greatest in government school cleaners, mean results conveyed that:
‘… [all] cleaning workers who perform the task of vacuum cleaning are at risk of work-related upper-limb musculoskeletal injury, regardless of whether they use a back-pack or canister machine’.
Study authors, Alison Bell and Julie Steele, stressed ‘the need for further research to improve conditions for these workers’.
By contrast, the 2nd study was designed to evaluate the loads imposed on muscles and joints by excessive accumulation of physical burdens in vacuum cleaning works, with a view to estimating musculoskeletal disorder (MSKD) occurrence.
Results showed that latissimus dorsi and trapezius muscle strengths and elbow and shoulder joint moments were generally higher in vacuum cleaning than in other cleaning works. This relationship was further accentuated in corners and in hard-to-reach areas.
Consequently, the Korean researchers suggested that their study conclusions ‘may be used in improvement of vacuum cleaner … design reducing a potentiality of musculoskeletal disorder occurrence due to repeated cleaning works…’
Wireless, hand-held vacuum cleaners are still, to all intents and purposes, a novel invention, with Dyson having sold its first cord-free vacuum, the DC16 machine, in 2006. It is therefore understandable that there is a lack of research directly linking vacuuming with CTS. Nevertheless, in March of last year, Sir James Dyson announced that the cordless Dyson Cyclone V10 release signalled the end of the company’s ‘full-size’ vacuum development.
Figure: Dyson Cyclone V10
(Source: Wikimedia Commons)
Thus, if wireless vacuums are the future of vacuuming, it may be advisable for cleaning businesses and their EL/PL insurers to monitor the risk of CTS and WRULD in users.
Should manufacturers buy the rights to the Lofstrand Vacuum Cleaner, or create versions of their own for mass-production, businesses could soon be duty-bound to supply and enforce their employees’ use of ergonomically advanced equipment, especially if clinicians can definitively prove that wireless vacuuming aggravates the median nerve, with the potential to cause CTS.
 JAMES HOARE, ‘A FRESH TAKE ON THE VACUUM CLEANER’ (25 February 2019 Yanko Design) <https://www.yankodesign.com/2019/02/25/a-fresh-take-on-the-vacuum-cleaner/> accessed 27 February 2019.
 English CJ et. al, Relations between upper limb soft tissue disorders and repetitive movements at work Am J Ind Med. 1995 Jan;27(1):75-90 <https://www.ncbi.nlm.nih.gov/pubmed/7900737> accessed 27 February 2019.
 Di Carlo D et al, Carpal tunnel syndrome and cleaning work: a binomial that should not be overlooked, G Ital Med Lav Ergon. 2003 Jul-Sep;25 Suppl(3):247-8. https://www.ncbi.nlm.nih.gov/pubmed/14979171> accessed 28 February 2019.
 Alison F. Bell & Julie R. Steele (2012) Risk of musculoskeletal injury among cleaners during vacuuming, Ergonomics, 55:2, 237-247. <https://www.ncbi.nlm.nih.gov/pubmed/14979171> accessed 28 February 2019.
 Lim, D, et al, Evaluation of loads imposed on muscles and joints by repeated vacuum cleaning works for estimation of a potentiality of musculo-skeletal disorder occurrence. Int. J. Precis. Eng. Manuf. (2012) 13: 429. <https://link.springer.com/article/10.1007/s12541-012-0055-x> accessed 28 February 2019.
 Rebecca Smithers, ‘Dyson announces cordless future with end of plug-in vacuums’ (6 March 2018 The Guardian) <https://www.theguardian.com/technology/2018/mar/06/dyson-announces-cordless-future-with-end-of-plug-in-vacuums> accessed 1 February 2019.