Vibration injuries and underwater work 1 [Eng]

When I started working in the diving industry over 10 years ago, I never really thought about the health effects of vibrating tools: "using a drillhammer now and then can’t be that bad?" If anything, I thought it was rather nice if my hands were a bit numb after a day on the site; it sort of showed that I actually been working. However, over the years, I have seen several colleagues suffer from vibration injuries, and honestly, my own hands and shoulders are much more sensitive today than they were 10 years ago. Once you've acquired these types of injuries, they stay with you for life and often result in dramatic limitations on your future life quality. As a diver, it's very difficult to assess the occupational hazards you're exposed to because research in this area is often insufficient and rarely aligns with the time pressures and practical conditions of the job. This text is written to contribute to better practices regarding vibrating tools in underwater work. In the first part, I discuss vibration injuries and underwater work based on existing research. In upcoming parts (2 and possibly 3), I will discuss practical approaches to vibrations (threshold values, protective gloves, etc.) and the judicial tools available to safety representatives to address this issue.

 

PART 1

When talking about vibration injuries, one usually refers to HAVS (Hand-Arm Vibration Syndrome), which is a collective term for injuries resulting from hand-arm vibrations (HAV) from handheld machines. The exact diseases included in the concept of HAVS are still subject to debate. Vibrations are associated with changes in bones and cartilage, neuromuscular changes, osteoarthritis, hearing damage, and vascular damage. [5,3] There is also research suggesting that the injuries may not be limited to hands and arms, but that vibrations are also linked to brain damage and increased risk of heart attacks. [3] Since working with vibrating tools is often associated with other forms of stress and workplace shortcomings, it is difficult to determine the causation. It is simply challenging to determine why, for example, a construction worker has developed a particular strain injury when both work tasks and the work environment involve multiple potential causes that also interact with each other. Even for those who work with vibrating tools themselves, it is extremely difficult to distinguish the symptoms from other pains caused by factors such as poor posture or fatigue. Additionally the fact that HAVS has a symptom onset (latency) ranging from 6 weeks to 14 years doesn’t make things easier. [3]

Overall, regarding neurosensory damage (neuropathy), white fingers (Raynaud's phenomenon), and to some extent carpal tunnel syndrome, the causal relationship is widely accepted among researchers. Working with vibrating tools is estimated to increase the risk of neurosensory damage and white fingers by approximately 700% and 300% for carpal tunnel syndrome, respectively. [6] Typically, it is the neurosensory injuries that first manifest as tingling, numbness, decreased grip strength, increased clumsiness, and temperature sensitivity. It usually takes three times as long for vascular damage to become apparent, often in the form of clearly demarcated areas on the fingers, hence the name white fingers. [6] Carpal tunnel syndrome is caused by constriction in a nerve canal (the carpal tunnel) at the wrist and has symptoms that are difficult to distinguish from injuries to the nerve itself. An important difference is that the constriction of the carpal tunnel can often be addressed through treatment, whereas both neurosensory damage and white fingers are permanent injuries.

The research on the relationship between HAVS and professional diving is very limited. To my knowledge, there is only one relevant study, a small Japanese experimental study from 1995. [1] In the experiment, four recreational divers were repeatedly asked to use a pneumatic chipper at a depth of 4 meters in a 32-degree Celsius pool. The divers' temporary threshold shift (TTS) was measured at two-minute intervals and compared against measurements taken after dives without tool usage and corresponding tool usage on the surface. The results showed that the divers experienced a significantly higher degree of TTS and a longer recovery period after vibration exposure underwater, while diving without vibrations did not result in significant TTS. The study suggests that there is something in the conditions of underwater work that makes vibrations more harmful compared to vibrations at atmospheric pressure. The research team concludes that there are significant knowledge gaps regarding what in underwater work causes the prolonged TTS.

The research on the relationship between ergonomic factors and vibrations is also relevant to underwater work. Due to the water temperature, diving operations in Sweden are generally performed with dry gloves and relatively thick inner gloves. This means that tool handling is often strenuous for the hands and forearms, and to alleviate strain and cramping, straps are sometimes used on tool triggers. Experimental studies show that both grip strength and pressure affect the amount of vibrations transmitted from the tool to the hand and arm. [5,11,12] At the same time, padding seems to provide poor protection against vibrations. In several studies, anti-vibration gloves have only shown effectiveness against certain vibration frequencies while amplifying others. Therefore, the recommendation is to carefully consider their use, as thicker gloves can lead to hand fatigue, finger stiffness, and changes in tool grip and force distribution, while the protection against the most harmful frequencies is questionable. [5,12]

Uncomfortable working postures are a common issue in underwater work. Experimental studies show that the transmission of vibrations between the tool and the hand increases when the work is performed in an uncomfortable and tense posture compared to a comfortable and relaxed posture. [5,12,14,15] In a Scottish study from last year, both vibrations (m/s^2) during work and reduced sensation (TTS dB) during work in different postures were compared. The study shows that upward drilling results in higher sensory loss compared to downward drilling, despite downward drilling on average having 55% higher vibrations. [15]

Hand temperature can also be a complicating factor in underwater work. The general recommendation is to keep hands warm and dry when working with vibrating tools, as both vibrations and cold temperatures restrict blood flow in the arms. The idea is simply that cold and vibrations have a harmful interaction. This theory is supported by several laboratory studies where vibrations are associated with decreased hand temperature. [8,9,10] Additionally, it is evident that vibration injuries are more frequently encountered among construction workers in northern Sweden than in the southern region, although no causal link can be established.[i] [7]

IN SUMMARY, the research indicates several unfavorable associations between factors in underwater work and vibration exposure. Although the relationship between diving and HAVS is understudied, the research is stable regarding the connections to ergonomics and temperature.

 

References

 

1.       Setsuo MAEDA, Yoshiharu YONEKAWA, Kazuo KANADA, Yukio TAKAHASHI and Michael J. GRIFFIN, Vibrotactile Temporary Threshold Shifts Induced by Hand-transmitted Vibration during Underwater Work, Industrial Health,33, 1995.

2.       Stefan Weyna, Vibrations transmitted by hydralic driling machines in underwater drilling conditions, Ship research institute, 1992.

 

3.       Pia Rehfisch, Robert, Wålinder, ABC om vibrationsskador, Läkartidningen, 2009, Vol.106 (7), p.451

 

4.       Michael Uhl, Tim Bruchmüller, Sven Matthiesen, Experimental analysis of user forces by test bench and manual hammer drill experiments with regard to vibrations and productivity, International Journal of Industrial Ergonomics, Volume 72, 2019, 398-407, https://doi.org/10.1016/j.ergon.2019.06.016.

 

5.      5.  Michael H. Weier, The Association Between Occupational Exposure to Hand–Arm Vibration and Hearing Loss: A Systematic Literature Review, Safety and Health at Work, Volume 11, Issue 3, 2020, 249-261, https://doi.org/10.1016/j.shaw.2020.04.003.

 

6.       6. Nilsson T, Wahlstro¨m J, Burstro¨m L, Hand-arm vibration and the risk of vascular and neurological diseases—A systematic review and meta-analysis. PLoS ONE 12(7), 2017. https://doi.org/10.1371/journal.pone.0180795

 

7.       7. Lage Burström, Bengt Järvholm, Tohr Nilsson and Jens Wahlström, White fingers, cold environment, and vibration - exposure among Swedish construction workers, Scandinavian Journal of Work, Environment & Health , 2010, Vol. 36, No. 6, 509-513.

 

8.      8.  Dong, R.G.; Wu, J.Z.; Xu, X.S.; Welcome, D.E.; Krajnak, K. A Review of Hand–Arm Vibration Studies Conducted by US NIOSH since 2000. Vibration 2021, 4, 482–528. https://doi.org/10.3390/ vibration4020030

 

9.      9.  Forouharmajd F, Yadegari M, Pourabdian S. Hand-arm vibration effects on performance, tactile acuity, and temperature of hand. J Med Sign Sens 2017;7:252-60.

 

10.    PETTERSSON, Hans ; RISSANEN, Sirkka ; WAHLSTRÖM, Jens ; RINTAMÄKI, Hannu Skin temperature responses to hand-arm vibration in cold and thermoneutral ambient temperatures, Industrial Health, 2018, Vol.56(6), pp.545-55.

 

11.    Michael Uhl, Tim Bruchmüller, Sven Matthiesen, Experimental analysis of user forces by test bench and manual hammer drill experiments with regard to vibrations and productivity, International Journal of Industrial Ergonomics, Volume 72, 2019, 398-407, https://doi.org/10.1016/j.ergon.2019.06.016.

 

12.    Hamouda K, Rakheja S, Dewangan KN, Marcotte P. Fingers' vibration transmission and grip strength preservation performance of vibration reducing gloves. Appl Ergon. 2018 Jan;66:121-138. doi: 10.1016/j.apergo.2017.08.005. Epub 2017

 

13.    Sasikumar, R., Lenin, K. Assessing the influence of hand-arm posture on mechanical responses of the human hand during drilling operation. Int J Adv Manuf Technol 93, 375–384 (2017). https://doi-org.proxy.ub.umu.se/10.1007/s00170-016-9470-y

 

14.    Saha, Siddhartha ; Kalra, Parveen A review on hand-arm vibration exposure and vibration transmissibility from power hand tools to hand-arm system International Journal of Human Factors and Ergonomics, 2016, Vol.4 (1), p.10-46

 

15.    15.Taylor, M.; Maeda, S.; Miyashita, K. An Investigation of the Effects of Drill Operator Posture on Vibration Exposure and Temporary Threshold Shift of Vibrotactile Perception Threshold. Vibration 2021, 4, 395–405. https://doi.org/10.3390/ vibration4020025

 


[i] It cannot be determined whether the symptoms are caused by or become more pronounced due to the cold climate.


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