The Role of "Clustering" in Running-Related Injuries

If you are like most people, you do the majority of your long runs on the weekend. The typical 9:00-5:00 work day leaves little time to squeeze in anything over a 5 mile run during the week, especially this time of year, when the days are getting shorter. The result is often a behavioral phenomenon called clustering, which refers to performing a large portion of our physical activity (in this case, running) in a short period of time. Think of the runner training for a marathon, getting out for 5 mile runs 3 days per week due to time constraints, before performing a 20 mile training run on the weekend. The long run for this individual would be over 50% of the weekly training mileage, which puts them at an increased risk of injury. When considering how to organize or arrange our training mileage for a given week, we want to consider the 70/30 rule, which states that our long run each week should not exceed more than 30% of our total weekly training mileage, while the mileage from the rest of our training runs should add up to at least 70% of our total weekly training mileage. Following the 70/30 rule helps to promote consistency, creating a better environment for your tissues to adapt gradually over time. Following this rule also helps to promote specificity in training, as we need to consistently run long distances in order to run long distances well. In other words, running 5 miles is not the best way to help you run 26.2 miles well. Rather, running distances as close to 26.2 miles consistently will preferentially help you run 26.2 miles well. While training speed does not apply to the 70/30 rule, specificity applies to speed as well: training fast is the best way to help you run fast (i.e. training slow does not help you run fast).

Now there are a lot of other rules out there we are instructed to follow when training: the 10% rule (do not increase your weekly training mileage by more than 10% per week), the 40 mile rule (training beyond 40 miles per week increases your risk of injury), the 6 days per week rule (running 6 or more days per week increases your risk of injury, the 13 mile rule (running 13 miles or more for your long run more than once over a 2 week period of time increases your risk of injury). Finding a training program that adheres to all of these rules can be rather difficult so it is important to note that these are simply rules designed to help reduce our risk of injury and breaking them does not guarantee that we will get injured. The key is to follow the rules that seem to have the greatest impact on how we run. For example, if you consistently notice running over 40 miles per week tends to result in your knee hurting, but you can run every single day of the week without issue, the 40 mile rule may be important to adhere to, while the 6 days per week rule might be one you can ignore. Consistency seems to be one of the more important aspects of training though, which is why the 70/30 rule and the concept of clustering are so relevant. Big outliers in our training tend to result in tissue irritation or injury. A consistent training program, with slow and methodical increases built in will help you progress at the safest and fastest rate possible because this allows you to minimize your risk of injury. Getting injured is a sure way to slow down your training program, which will ultimately slow down your progress. In other words, you need to progress slowly in order to progress as quickly as possible.

Train smart!

-Grant Hennington, DPT

By The Numbers: Injury Risk In Runners

Running is a tremendously popular sport, with approximately 40 million people running regularly in the United States. This is not particularly surprising given all of the well-documented health benefits of this form of physical activity. Unfortunately, running also carries with it a high rate of injury, with up to half of runners experiencing an injury on a yearly basis. While many factors play into this high rate of injury among runners, two primary risk factors stand out: history of previous injury and overtraining. With these in mind, here are some important numbers to be aware of when designing or following a training program.

• 40

  • Multiple studies have shown that running greater than 40 miles per week significantly increases the risk of injury

• 13

  • Runs longer than 13 miles should be done no more than once every 14 days, as exceeding this significantly increases the risk of injury

• 10%

  • While this number is hotly debated due to inconsistent evidence, it is generally accepted that increases in weekly training mileage should not exceed 10% per week, as doing so increases the risk of injury

• 6

  • Running 6 or more days per week significantly increases the risk of injury

• 4-5

  • With respect to injury, most regular runners do best when training no more than 4-5 days per week, with at least 1 day of rest and 1-2 days of cross-training built in

• 2-3

  • Runners should limit themselves to no more than 2-3 marathons per year

Keep in mind that these are numbers from a variety of prospective and retrospective studies on specific populations of runners and may not directly apply to you. However, they do help provide metrics for you to use when evaluating your own training program, whether it be for your first 5k or your attempt to qualify for the Boston Marathon. In general, most training programs should progress slowly, incorporate rest days, and include cross-training exercises that promote improved strength and stability. It is difficult to enjoy running when injured so keep these numbers in mind, as they may help you lower your overall risk of injury when training for your next race.

Run safely!

-Grant Hennington, DPT

Why Is The Bottom Of My Foot Hurting?

You may have heard the term plantar fasciitis when asking around about pain in the bottom of the foot or researching your symptoms, but what is it and why is it inflamed? The plantar fascia is a thick fibrous band of tissue that runs along the bottom of the foot, starting along the heel and connecting to the base of the toes. It’s main purpose is to provide support to the arch along the inside of your foot. Just like any other tissue of the body, it can become stressed, strained, irritated, and/or inflamed, leading to pain anywhere from the heel to the arch of the foot. The plantar fascia is most commonly stressed due to decreased flexibility, higher body weight, increased pronation (or flat feet), activities involving prolonged weight bearing, or a rapid increase in activity levels, such as the beginning of a new running program. All these factors can place increased stress along the arch of your foot and the plantar fascia, leading to inflammation and possible pain.

So what can you do to reduce the pain and improve mobility? Physical therapy is a proven method for treating plantar fasciitis, helping patients to develop a personalized program to reduce pain and improve mobility. Typically, physical therapists will address flexibility and strength impairments, while also utilizing specific taping methods and going over proper shoe selection. Here are a few exercises typically used to treat plantar fasciitis:

Calf Stretch

Seated Plantar Fascia Stretch

Plantar Fascia Myofascial Release

If your symptoms seem to be lingering or you have more questions, contact us in order to schedule an appointment with one of our qualified physical therapists for evaluation and treatment. Get started now!

-Brian Collins, DPT

Pronation: Not Always The Bad Guy

Physical therapists frequently analyze the running mechanics of individuals in a clinical setting, as running is an activity that carries with it a relatively high rate of injury. In fact, per athlete more injuries occur from running than from CrossFit, a sport with a reputation for being injury provoking. Far too often in working with runners, I hear many individuals talk about their tendency to pronate during the running cycle, as if pronation is a 4-letter word and the root cause of all running-related injuries. However, I’m here to tell you today that pronation is a perfectly normal and healthy aspect of the running cycle, allowing us to absorb shock and conform to undulations in the ground, as a pronated foot tends to be more pliable and flexible. Here is a synopsis of the foot position at various points in the running cycle:

• At initial contact (heel strike in approximately 80-90% of individuals), the foot is held in a supinated position, which means the arch of the foot is high and the foot as a whole is more rigid.

• As you transition from initial contact to a foot flat position, the foot transitions from a supinated position to a pronated position in order to quickly dampen the force from striking the ground and conform to the contours of the ground. An inability to pronate during this phase would expose the tissues in your foot to higher amounts of force, making running more uncomfortable. This would be similar to jumping off of a table and landing on locked knees.

• As you transition from a foot flat position to push-off, the foot must quickly transition back to a supinated position from a pronated position in order to efficiently propel you forward. As we mentioned earlier, a supinated foot is more rigid and a pronated foot is more flexible. A greater propulsive force can be generated by pushing off of a rigid foot compared to pushing off of a flexible foot. The inability to re-supinate the foot for push-off would feel similar to running in sand.

So as you can see, pronation is not a bad thing. Too much pronation or at the wrong times in the running cycle could be problematic, but that is true of supination as well. Furthermore, research on the link between pronation and running-related injury is a bit inconclusive. While it is true that some running-related injuries have been correlated with excessive pronation, there is some evidence that it can actually be a compensatory protective strategy in runners.

The foot has been shown to excessively pronate as a result of a lack of stability up the chain, typically at the hip joint. Therefore, it may not always be wise to simply jam an orthotic insert in your running shoes if you have been told you are “over pronating” when you run. A running analysis along with a thorough orthopedic physical therapy examination should precede any decision on the use of orthotic inserts or footwear selection. How we run is determined by more than just the foot and we need not blame all of our running aches and pains on pronation.

-Grant Hennington, DPT

Foam Rolling 101 for Endurance Athletes

Have you ever been told you need to foam roll as part of your training program? If so, did you know why you were foam rolling or how you were supposed to go about doing it? Here is a quick Q&A guide to those interested in a simple and effective training tool.

What is foam rolling?

Foam rolling is a common form of self-myofascial release most often used by endurance athletes to help combat delayed onset muscle soreness (DOMS).

What are the benefits of foam rolling?

While foam rolling is most often used to treat muscle soreness and enhance recovery following intense bouts of exercise, foam rolling has also been shown to be an effective tool for improving joint range of motion at the hip, knee, and ankle without compromising muscle performance. Therefore, it can be beneficial when used either pre or post-workout. You will often see foam rolling utilized as a therapeutic tool used to treat Patellofemoral Pain Syndrome (i.e. runner’s knee), IT Band Syndrome, Achilles Tendintis, and Medial Tibial Stress Syndrome (i.e. shin splints).

What areas should I focus on?

Targeting sore areas of the muscles in the legs following a training session can be an effective way to enhance muscle recovery and reduce the negative effects of DOMS. Common regions to foam roll in the legs are the calves, hamstrings, gluteals, quadriceps, IT bands, and adductors. Here is a video of a sample foam rolling routine for runners:

What areas should I avoid?

In general, foam rolling is limited to soft tissue, as it is a self-myofascial release tool. Avoid rolling over bony prominences (bumps) or joint surfaces, as this is more likely to be aggravating as opposed to therapeutic.

How long should I foam roll each region?

Studies suggest that foam rolling an area for 30-60 seconds is sufficient to enhance joint flexibility and reduce muscle soreness. No need to roll much longer!

Other considerations...

Foam rolling is meant to be a tool utilized in conjunction with, not a substitute for, other evidence-based training principles. It will not eliminate your risk of getting injured if you are over-training or training inconsistently. As always, please consult your primary care provider or physical therapist if you have any questions or concerns before implementing a new wrinkle to your exercise routine, such as foam rolling. If you experience any progressive increase in pain or discomfort with foam rolling, stop and seek guidance from a healthcare provider or fitness professional.

-Grant Hennington, DPT