Sometimes you can feel it starting as soon as you position yourself to begin working on a patient, especially if that patient is at the end of the day. It starts as a small feeling of discomfort. You ignore it. You only have X amount of time to finish this procedure so that you can stay on schedule. But eventually, the discomfort escalates into a nagging pain. You find it difficult to hold your neck in the right position, reach for your instruments or sit so that you can see properly. Now you try to shake it off, take a quick look at the ceiling, sit up a little straighter, maybe you even stand up for a second. Ahhhh……relief. At least until you return to your working position only to find that the relief was temporary and this time it is even more intense.
Muscle fatigue is a serious problem in the field of dentistry. It is a significant source of musculoskeletal impairments and affects productivity levels, absenteeism, use of pain medications and quality of life outside of work (Rundcrantz BL, 1990). Although muscle fatigue can occur in any muscle, dental professionals are more likely to report fatigue in their necks, shoulders, low back and hands (Hayes, 2009) (Puriene A, 2008). If not addressed, fatigue can lead to a variety of impairments to the muscular, skeletal, cardiovascular and nervous systems.
Fatigue is a physiological state reached when a muscle is deprived of vital nutrients and byproducts of metabolic activities accumulate. A resultant from static contractions, fatigue inhibits proper functioning of the muscle and associated vascular components. As the muscle contracts, the increased pressure can occlude the small blood vessels blocking the delivery of the nutrients and removal of wastes.
The initial feeling of discomfort is a warning signal to your brain that these vessels are compromised. After receiving the distress call, the brain attempts to clear the obstruction by sending signals of discomfort to your muscles to move so that blood can return to the ischemic tissue. However, if this first signal is ignored, the blockage continues. The brain becomes a little more insistent. Pain begins. For more about how the brain is actually the source behind pain, take a look at
In a perfect world, you would heed this first warning signal and take a break from your position to improve blood flow. You may even do things to encourage blood flow to that area. This process takes between 30-180 seconds. You would be able to return to your working position for a longer period of time before experiencing another warning signal.
Why does anyone typically ignore the first warning signal? The more “cerebral” part of your brain is aware of your task, your schedule, your finances, and will often override this first (or maybe 5th) warning. Since the initial signal does not provoke excruciating pain, you ignore or “work through” it, furthering the damage. If you are ignoring these signals regularly throughout your day, the muscles will require significant time to recover. The process will take much longer than 30-180 seconds. Instead, recovery time could now take hours. (Blangsted AK, 2005)
But life doesn’t end at the end of the work day. In fact, that is hopefully when you get to enjoy our preferred activities. Those activities require the same muscles to work that have been strained all day and which are supposed to be in recovery mode. Research in biomechanics reveals that people are most likely to sustain a work related injury AFTER work as they perform what seems like ordinary or simple tasks (Le B, 2009). This happens because the muscles are physiologically unable to perform properly as they have been deprived of nutrients throughout the day.
Protect yourself from muscle fatigue.
Using the following strategies can help reduce your risk of fatigue and related muscloskeletal pain.
1.Stretch muscles that usually become painful before you begin each procedure, no matter how short.
2. Review your posturing, patient positioning and ergonomic situation. Make sure it is appropriate for you.
3. Take regular 30 second breaks. Make sure this is actually 30 seconds. You cannot count by twos and get results. It takes time for the blood to return.
4. Use breaks to perform active exercises that can improve circulation. See the previous blog: 30 Second Exercises to Help Alleviate Neck Pain. Other blogs will follow for other body regions that are often painful.
5. Allow for ample recovery time after work. Try these:
Ø Avoid prolonged sitting without breaks
Ø Avoid prolonged computer usage for neck/hand/wrist pain
Ø Avoid work that requires bending or twisting for back pain
Ø Avoid overhead work for shoulder pain
If not managed and controlled, muscle fatigue has devastating consequences, both professionally and personally. Understanding the mechanisms of fatigue, heeding warning signals, and taking active steps to protect yourself can empower you to take control of your pain and your life.
Blangsted AK, S. G. (2005). Voluntary low-force contraction elicits prolonged low-frequency fatigue and changes in surface electromyography and mechanomyography. Journal of Electromyography And Kinesiology: Official Journal of the International Society of Electrophysiological Kinesiology, 15(2), 138-148.
Hayes, M. C. (2009). A systematic review of musculoskeletal disorders among dental professionals. International Journal of Dental Hygiene, 3(7), 159-165.
Le B, D. B. (2009). Neuromuscular controal of lumbar instability following static work of various loads. Muscle & Nerve, 39(1), 71-82.
Puriene A, A. J. (2008). Self-reported occupational health issues among Lithuanian dentists. Industrial Health, 46(4), 369-374.
Rundcrantz BL, J. B. (1990). Cervical pain and discomfort among dentists. Epidemiological, clinical and therapeutic aspects.Swedish Dental Journal, 14(2), 71-80.
Do you struggle with muscle fatigue?