“Overuse injury” is becoming a well-known term among health professionals, pro athletes, amateur athletes, and parents. The term overuse implies that there is a known level of activity that is appropriate for an individual (based on age, previous/current injuries, experience,etc), and once this known level is exceeded, overuse occurs. Even if a thorough assessment is performed, it is still difficult to determine the appropriate activity level for an individual, especially if previous injuries linger, or are in a person’s past medical history, and also due to pressure/adherence from the athlete.
In their 2004 article, “Overuse injuries: tendinopathies, stress fractures, compartment syndrome, and shin splints” Wilder and Sethi describe overuse injuries as being the “result from repetitive microtrauma that leads to local tissue damage in the form of cellular and extracellular degeneration, and are most likely to occur when an athlete changes the mode, intensity, or duration of training—a phenomenon described as the ‘principle of transition'”. Typically these microtraumas result in changes such as muscle growth, hypertrophy of tendons, etc, but when the trauma is not allowed to heal, the body continues to breakdown. Depending on the athlete’s diet, sleep requirements, activity level, adherence to program design, and a few other factors, these microtraumas will usually heal resulting in an advantageous or desired tissue change; however, when these needs are not met and deficiencies are present such as muscular weakness/stiffness/tightness, inappropriate joint mobility, and poor motor control the result is often “overuse”.
Because knowledge of overuse injuries is spreading, I am starting to hear more questions regarding the term “overuse”. “Mike, how come you’re saying I cannot run at all, when I used to be able to run five miles three times a week?” or “how come you don’t think I should train for a half-marathon?”. The truth is that even running to catch the bus for some of these patients is probably too much. I often have to delve into the fact their appropriate activity level is much less than the level that landed them on my tables. Once a patient becomes able to return to activity, it must be graded, and the patient must be, well, patient.
It is not just the fact that these people did too much, too fast, for too long. There are plenty of people who sustain a high levels of activity without consistently having an overuse injury (marathoners, triathletes, professional athletes). For the most part, my patients do perform too much, too fast, for too long, but they also have underlying movement dysfunctions that causes undue stress on tissues. It is the equation of movement deficiency plus too much/fast/long that leads to “overuse”.
The general point of this post is that the appropriate level of activity before “overuse” is reached is different for everyone. Also, overuse does not have to be in the legs because of running. It can be in pretty much in any joint, but can also result in soft tissue dysfunctions such as tendonitis/osis, stress reactions/fractures, and muscle strains. I do not like suggesting “rules of thumb” because there are always better ways to do things, but when advising patients who are being discharged to an independent home exercise program, I will suggest the 10% rule; however, seeking the advice of a HIGHLY qualified strength and conditioning professional is always best. A review of MY General 10% Rule:
1. Do not increase frequency, speed, volume, intensity, or duration more than 10% a week.
2. Do not increase more than one of these factors per week. This is because of the scientific method. How will you know what caused pain if you change more than one variable in a week?
3. If you have pain when increasing one variable, the next time you perform the activity decrease to the previous level. Also, you must think if anything else changed. Did the activity surface change, did you wear different shoes, did you lift using different equipment, and so on? Upon the next week, if pain-free, attempt to increase a different variable than that one that caused pain.
Unfortunately overuse injuries are becoming more and more well-known. In a perfect world I would not be treating the weekend warrior who sits all week then tries to run 10 miles in a weekend. Everything in moderation right? That goes for returning to activity as well.
Please leave your questions and comments, and if you would like to contact me directly, send an e-mail to mikescott.dpt@gmail.com
The link to the mentioned article – http://www.med.nyu.edu/pmr/residency/resources/Clinics_sports%20med/clinics%20NA%20sports_overuse_tendin_stress_compartment_shin.pdf
Mike Scott, DPT 