Identifying lower limb problems and the types of safety footwear worn in the Australian wine industry: a cross-sectional survey

The Australian wine industry is a valuable part of the wider Australian economy, worth approximately A$45 billion annually and employing 163,790 people either full time or part time [1]. Therefore, the wine industry and the health and safety of its workers are an important part of Australian society and the economy. The industry is also somewhat unique, in that most businesses are small to medium in size and consist of multiple workplace environments within the one entity [2]. In 2020 there were 2361 wineries and 6251 grape growers in Australia. Approximately 64% of producers are considered small to medium and process less than 50 t of grapes per year, 20% process 50–499 t and 16% process more than 500 t [2].

Wine business owners and employees may work in various combinations of roles across the business, particularly in smaller, family run enterprises. Small wineries are comprised of a primary industry (grape growing), a secondary process (wine production) and tertiary activities such as restaurants and cellar door sales [3]. Grape growing activities can include operating heavy machinery as well as driving tractors and harvesters in the vineyard. Winery activities can include operating forklifts/pumps/crushers/conveyor belts and bottling machines, along with analysing juice and wine samples in the laboratory plus general office work. Sales and hospitality work in the cellar door can often include food service. Most of these activities involve wearing protective safety footwear and standing for long periods. This is particularly the case during the vintage/harvest season, when the weather is very hot and shifts are longer than usual due to the time constraints involved in harvesting and processing grapes at the optimal time.

To date no data have been published on the types of injuries experienced in the Australian wine industry and the cost of injury to the industry. However, the South Australian government, which is the largest wine production area in Australia and accounts for 52% of the national output, publishes data on workplace injuries across several industries [2, 4]. The majority of injuries reported by the South Australian government in 2020 were for technicians/trade workers (27.9%), labourers (26.6%) and machinery operators/drivers (16%). The injuries were predominantly upper limbs (38.5%), lower limbs (18.9%) and trunk/back (17.9%). The nature of the injuries were mainly traumatic joint/ligament/muscle/tendon injuries (37%), wounds/lacerations (29.1%) and musculoskeletal diseases (15.2%). The main mechanism for these injuries were body stresses (34.5%), being hit by an object (19.4%) and falls/trips/slips (17.3%) [4]. In 2012–13, work-related injury and disease cost the Australian economy A$61.8 billion, representing 4.1% of the gross domestic product [5].

Injuries among vineyard workers appear to be common. A study in France found that vineyard workers were likely to experience musculoskeletal pain. They reported upper limb pain (31.2%), neck/shoulder (28.9%), lower limb (25%) and back pain (55%) prevalence during grapevine pruning and grape harvesting [6]. Similar results have been seen with vineyard workers in the United States [7‐9], Italy [10] and Argentina [11], but no specific data exists for Australian vineyard workers or winery workers in general.

Whilst there is limited data available for the wine industry, much can be gleaned from other agricultural industries that are reportedly some of the most dangerous workplaces [12]. For example, manual harvesting is prevalent in many agriculture industries and is the largest contributor to work-related musculoskeletal disorders [12]. The Australian aquaculture industry reports that 37.3% of injuries are body stressing events and that lower limb injuries account for 20.3% of all injuries [13]. The majority of these industries involve spending prolonged hours standing and it has been demonstrated that this can increase the risk of musculoskeletal disorders such as lower back, lower extremity and foot disorders [14].

Work environment flooring and footwear have also been demonstrated as risk factors [15], considering the variable nature of wine industry work environments, this is an area that warrants further investigation. Safety boots are compulsory in many occupations to protect the feet of workers from external stimuli, particularly in harsh environments [16]. The unique environmental conditions and tasks in different occupations necessitates a variety of boot designs to match each workers occupational requirements [17]. Unfortunately, safety boots are often designed more for safety at the expense of functionality and comfort [17].

Further risk factors for agricultural and horticulture workplace injuries include working full time, being the owner/operator, medication use, prior injury, poor health, stress/depression, poor hearing [18], heat stress [19] and inadequate sleep due to shift work [20, 21].

When these risk factors and the nature of wine industry work are taken into consideration, especially during the busy vintage/harvest period, it can be seen that wine industry work environments pose a potential risk to injury. Therefore, the aims of this study were to (1) identify whether lower limb problems occur in the Australian wine industry and (2) identify the types of safety footwear used.

To the best of our knowledge, this preliminary study is the first of its kind to identify whether lower limb problems occur in the Australian wine industry and what types of safety footwear are worn. It has also taken a snapshot of how these problems affect workers and how workers perceive their footwear. The survey was not comprehensive however, it has provided valuable information for developing further research into the future. For example, the nature of the work involved in each role was not explored in great detail, that is, how much time workers spent standing, walking or sitting in each role. Previous research has reported that an estimated 50% of the working population experience musculoskeletal disorders due to prolonged standing and that standing is implicated in lower back, lower limb and foot pain [30, 31].

Lower back pain was the most commonly reported problem at 56% followed by foot pain (36.7%), If foot, toe and heel pain are combined to total foot pain, 60.8% of respondents experienced some type of foot pain. Only 19.3% of respondents reported no lower limb problems, which is a common limitation of such self-selected surveys [18]. The results are similar to those reported for miners and their work boots, that is, lower back pain (44.5%), foot pain (42.3%), knee pain (21.5%) and ankle pain (24.9%) [18].

The majority of lower limb pain experienced by participants was in the ‘mild’ to ‘moderate’ range (Table 1) and it was experienced ‘occasionally’ to ‘many times’, it did not however have a large impact on the ability for workers to complete their daily activities. Only vigorous activities, bending and climb a hill were in the ‘a little’ to ‘moderate’ range (Table 2). This could explain the unwillingness of participants to seek treatment for lower limb problems, as they may have felt that it was a ‘normal’ part of their work. Overall, physical health wasn’t reported as being a concern, as was seen in Table 6, with the majority of respondents disagreeing with the statements about problems with work or other activities as a result of their physical health.

The majority of participants’ general health was reported as being ‘very good’ to ‘excellent’ with very few reporting that their health was ‘fair’ to ‘poor’ (Table 5). However, 54.1% agreed with the statement ‘I feel tired’ and 21.7% agreed with the statement ‘I feel depressed’. This figure for depression is similar to that reported by the Australian Bureau of Statistics [32] where 20.1% of Australians reported themselves as having an anxiety-related condition and depression or feelings of depression. While this survey was conducted during the SARS-CoV-2 pandemic, which may have impacted the mental health of the respondents, at the time of the survey no Australian states were under government sanctioned stay at home orders, but international travel restrictions were in place.

Respondents reported using additional support or cushioning in their shoes, however no details on the types of support or cushioning were recorded. That is, whether it was a custom-made foot orthosis or an off the shelf insole. Dobson et al. [17] reported that in the mining cohort they studied, only 6.7% of respondents wore health professional prescribed orthoses. Flat insoles and contoured foot orthoses have been shown to increase plantar pressures at the midfoot, reduce plantar pressures at the rearfoot, and provide small reductions in tibial accelerations when used in high cut, lace up, boots [33]. However, no differences in ‘boot comfort’ between the no insole, flat insole and contoured foot orthosis groups were identified in this previous study [33]. Therefore, no conclusions can be made as to whether the use of additional support or cushioning had an effect on respondents’ comfort in this preliminary survey.

Elastic sided safety boots were the most popular, followed by the high cut lace up safety boots with side zip. Even if high cut lace up safety boots are considered analogous to the high cut lace up safety boots with side zip, elastic sided safety boots are still the most popular. Also, workers that wear elastic sided safety boots are more likely to experience lower limb problems such as foot and lower back pain, however no link between footwear and lower limb pain can be inferred from this study. Safety footwear was also reported as being hot and heavy in this study. Heavy footwear has been associated with increased energy expenditure by workers wearing safety footwear [34]. Dobson et al. [17] report that 62.3% of miners believed that their foot and ankle pain was related to their work boots. One explanation for this is that miners may be wearing boots that are longer than their feet, possibly because boots in their correct length are too narrow [35]. Dobson et al. [36] concluded that traditional fitting methods based on foot length were insufficient when fitting miners. Grau and Barisch-Fritz [37] concur and state that foot width and girth measures are different in static and dynamic loading situations and must be considered when manufacturing and fitting safety footwear to aid in supporting workers health. Buldt and Menz [38] state that between 63 and 72% of the general population are wearing inappropriately sized footwear based on length and width measurements, and that incorrect footwear fitting is significantly associated with foot pain. In this study however, 73.9% agreed with the statement that their footwear fit well.

Many studies have explored the relationship between safety footwear and injuries with the majority focusing on; high cut lace up safety boots, military boots, gum boots, sports shoes [16] and surgical clogs [31]. These studies have identified many relationships, for example, gum boots are associated more with knee and heel pain while high cut lace up safety boots were associated with more leg and ankle pain [39]. Gum boots are associated with more force and contact area in the heel compared to the high cut lace up safety boots [40]. High cut lace up safety boots with varying sole and shaft stiffness are associated with effects on lower limb muscle activity, ankle motion [41] and plantar pressures [42]. High cut lace up safety boots also have an impact on postural control [43] and postural stability under workload [44]. High cut lace up military boots while carrying a workload also have an effect on postural stability and heel contact during slip events [45, 46].

To date no data exists on the effect of elastic sided safety boots in any industry. There is also no published data on how safety footwear is supplied to workers and protocols for when it is replaced in the wine industry. Recent research into shoe tread (sole) wear and wear measurement has highlighted the need for understanding the mechanism for shoe tread wear and individualised shoe replacement recommendations to prevent injury caused by the decline in traction of worn shoes [47‐49].

The popularity of elastic sided safety boots in the Australian wine industry is a unique phenomenon and its use therefore may be more due to tradition. Elastic sided boots were developed in the early 1900s to withstand the harsh, unforgiving environment of the Australian outback by providing a boot that was comfortable, rugged and able to cope with both hot/dry and cold/wet seasons [50]. They became popular heavy-duty footwear for farming, forestry, mining, and industrial uses [50]. Another reason for the popularity of elastic sided safety boots may be the nature of the work in the Australian wine industry. As has been highlighted, many wine businesses require workers to perform varying jobs over different sites and conditions, this often involves a quick change of suitable footwear, 79.2% of respondents agreed with the statement that their shoes are easy to put on and take off, which could also help to explain the popularity of elastic sided safety boots.

Boot design features have been shown to have an influence on the lower limbs depending on the task being performed and the supporting surface [16]. Therefore, occupational specific testing of footwear effects should occur in the Australian wine industry in order to try and accommodate for individual workplace environments.

This study has shown that lower limb problems occur in the Australian wine industry and that even if a problem is present workers often do not seek treatment or let the problem interfere with their work activities. This may be a function of the vintage/harvest season, when harvesting and processing grapes at their optimum condition places time constraints on workers. The study also demonstrated that elastic sided safety boots were the most popular amongst respondents.

These factors highlight the need for further research into the footwear used in the Australia wine industry to better support workers health while working in varied roles and conditions. A comparison of different footwear in different environments could take place as well as exploring the time taken for footwear to deteriorate in these environments. The optimum length of efficacy of the footwear could also be assessed to ensure footwear is replaced at appropriate times and not used when worn excessively. Future research is warranted to determine any barriers and facilitators regarding boot choice in the wine industry, especially when the multi-faceted work environments and the appropriate footwear for specific roles are taken into consideration.

As is the case with all surveys, there are limitations to this study and the accuracy of self-reported measures. This may have caused some selection bias, with participants who have experienced lower limb problems more likely to self-select to participate in the survey.

Recall bias can also be a problem, an attempt to minimise this risk was to set a 12 month limit on the survey, that is, participants were asked if they had worked in the Australian wine industry in the last 12 months. If they had not, they were directed to leave the survey. No demographic data on the participants were collected in this preliminary survey. Future research involving randomised control trials of specific footwear could include the collection of demographic data for more detailed analysis. Finally, it is not possible to conclude whether specific job roles had higher risks for lower limb problems with specific footwear. Correlations of these two factors does not imply any causation and requires further research to determine any relationship.