Fatigue In Modern Production

Allison Samia: Welcome back to The Injury Prevention Playbook! Today, we’re tackling a complex and essential topic for modern production environments: fatigue and its profound implications for musculoskeletal health. Fatigue is something we’ve all experienced in some form, but in the context of a production environment, it’s more than just feeling tired—it’s a key factor that can impact safety, productivity, and the quality of work. In this episode, we’ll dive into how fatigue, especially neuromuscular fatigue, plays a role in increasing injury risks, reducing motor control, and impacting long-term musculoskeletal health.   

Our discussion will cover the links between fatigue, ergonomics, and workplace safety, touching on how these factors can be proactively managed to help prevent musculoskeletal disorders (MSDs). We’ll also explore the influence of other factors like obesity, gender, and aging on fatigue and injury risk in the workforce. Let’s get started by unpacking what muscle fatigue means and how it affects our bodies, particularly in demanding work environments. 

Allison Samia: What are some of the most common physical areas affected by fatigue in industrial workers, and why are these areas particularly vulnerable? 

Kris Smith: In industrial settings, fatigue usually hits the trunk, shoulders, and hands the hardest. These anatomical areas are especially vulnerable because they handle a lot of the lifting, pushing, and repetitive motions required on the job. When you’re using these parts of your body all day, they tire out more quickly, making them prone to discomfort, reduced motor control, and even injury if the strain isn’t managed properly.  

Allison Samia: How does muscle fatigue impact motor control, and what implications does this have on the quality of the products being made? 

Kris Smith: Muscle fatigue actually affects how well workers can control their movements, leading to what’s called “poorer motor control.” When someone’s tired, they might not be able to handle fine motor tasks as precisely as usual. This lack of control can directly impact product quality—for example, someone might struggle to align parts correctly, which can cause assembly errors or defects. So, fatigue doesn’t just affect the worker—it can affect the final product too. 

Allison Samia: In what ways does prolonged fatigue contribute to the risk of developing work-related musculoskeletal disorders (MSDs)? 

Kris Smith: When fatigue builds up over time, it’s not just about feeling tired. This ongoing fatigue can lead to something called “fatigue failure,” where tissues in the body start to wear down and develop micro-injuries. Over time, these small, repetitive strains can build up into larger musculoskeletal disorders, like shoulder injuries or carpal tunnel syndrome. So, it’s the continuous strain that turns fatigue from just tiredness into an actual risk for long-term injuries. 

Allison Samia: How can fatigue lead to acute injuries, and what are some early signs that fatigue is setting in for workers? 

Kris Smith: Fatigue can make workers more prone to sudden, acute injuries. As muscles tire, they don’t respond as well, and reactions slow down, so there’s a greater chance of mistakes that can lead to accidents. Early signs of fatigue might include slower reaction times, a drop in focus, and discomfort or soreness in overused areas. Catching these signs early can be key to preventing more serious injuries down the line. 

Allison Samia: What tools can assist in identifying job tasks that can result in fatigue? 

Kris Smith: There are 3 main safety tools that can identify, assess and remediate fatigue:  

• PDA’s if completed using standardized terminology for essential functions, tasks and physical demands (or elements), can be valuable to understand how the job should be performed. From here, identification of specific job demands that are out of the safety zone, heavy or repetitive or require the use of awkward postures can be identified.  

• Another tool is an ergonomic risk assessment performed on the job and not the person performing the job. By assessing risk based on force, frequency, duration and cycle times, the ergonomic assessment can identify those tasks or physical demands where remediation can be effective.  

Allison Samia: How can ergonomics be used to minimize the impact of fatigue on workers? 

Kris Smith: Ergonomics is all about designing tasks and tools to fit the worker, which can make a huge difference in managing fatigue. Simple adjustments, like reducing how far someone has to reach or adjusting work surfaces to better heights, can help take the strain off muscles and joints. These ergonomic tweaks might seem small, but they go a long way in preventing fatigue and keeping workers comfortable. 

The last tool is a flexibility program. When there is not a solution for tool, equipment or process changes, looking at options that help the employee to avoid fatigue is the final solution.  Flexibility exercises improve blood flow and circulation and help to warm up muscles for the day’s work. In addition, flexibility exercises can be used throughout the workday to target muscles that are at the highest risk for fatigue. Frequent nourishment to muscles and use of opposite muscles can reduce fatigue as seen in several studies that have looked specifically at this area. 

Allison Samia: How does the concept of fatigue failure explain the development of MSDs in a production setting? 

Kris Smith: Fatigue failure is a process where tissues get worn down over time from repeated strain, almost like metal fatigue in machinery. In people, this means that repetitive tasks or heavy loads cause tiny tears in muscle and connective tissue. Over time, these little tears can add up to more serious injuries. It’s a gradual process that doesn’t usually start with visible injuries, but if left unaddressed, it eventually leads to MSDs. 

Allison Samia: Why is it important to address fatigue as a risk factor for MSDs before it progresses to visible injuries? 

Kris Smith: Fatigue is one of those risk factors that often flies under the radar until it becomes a full-blown injury. By the time fatigue progresses to something visible, like a shoulder or back injury, the damage has already been done. Addressing fatigue early means making small changes before those bigger injuries happen, saving both the employee and employer from the high costs of treatment, downtime, and potential compensation as a new injury or aggravation of an existing condition. 

Allison Samia: What are the specific challenges that obese or older workers may face in managing fatigue, and how can workplaces better support these groups? 

Kris Smith: Obese or older workers often face more challenges in managing fatigue. For example, older workers may experience fatigue more quickly due to natural aging, and obesity can make physical tasks even more exhausting, especially repetitive movements. Workplaces can support these groups by allowing more rest breaks, adjusting workstations to minimize strain, and encouraging practices like job rotation to spread physical demands. These adjustments help level the playing field and make sure everyone can work comfortably and safely. 

Allison Samia: In summary, it sounds like fatigue can have a major impact to a site by reducing productivity and quality, causing recordable injuries and impacting the ability of workers to be safe and comfortable when performing their job duties. It sounds like the first step is to assess the job demands and potential risk areas with a standardized method and definitions, then apply ergonomic changes to address tools, equipment and process changes. If these steps do not fully address the risk factors for fatigue, then adding a pre-shift and targeted flexibility program can assist workers to prevent fatigue throughout their workday. Easy as 1,2,3. Right? 

Kris Smith: Not easy but definitely a process that is objective, measurable and comprehensive. For those of you who need VPP, or ISO certification, these tools can set up your safety program for success.