Sports Medicine Research: In the Lab & In the Field: Risk Factors for Medial Tibial Stress Syndrome and Tibial Stress Fractures in Runners (Sports Med Res)
Monday, October 8, 2012

Risk Factors for Medial Tibial Stress Syndrome and Tibial Stress Fractures in Runners

Incidence and risk factors for medial tibial stress syndrome and tibial stress fracture in high school runners. 

Yagi S, Muneta T, Sekiya I. Knee Surg Sports Traumatol Arthrosc. 2012 Aug 9. [Epub ahead of print]
           
Medial Tibial Stress Syndrome (MTSS), also known as ‘shin splints,’ is commonly seen in runners and can be a very frustrating and nagging injury. Tibial stress fractures (SF) are another significant injury that can potentially force athletes to take long periods of rest. Despite the high frequency of MTSS and the implications of SF, it is unclear what risk factors may be related to these conditions.  Therefore, the authors of this study wanted to identify the incidence and also establish risk factors for these injuries. To do so, they performed a prospective study examining 230 high school runners in Japan for three years. The authors tallied the number of MTSS and tibial SF and examined the following risk factors: height, weight, body mass index (BMI), hip and ankle motion, straight leg raise, intercondylar and intermalleolar interval, Q-angle, navicular drop test and hip abductor strength. These measurements were done at baseline within four weeks of the student athlete entering school. All injury reporting was the responsibility of the school coach. The researchers were notified when an athlete could not train for seven days secondary to shin pain, and then the athletes were evaluated by the orthopedic clinic.  The authors found a total of 102 athletes with MTSS (58 male, 44 female) and 21 athletes with SF (7 male, 14 female) over the three years of the study.  BMI and internal hip rotation angle were significant risk factors for MTSS in females, while limited straight leg raise was a significant risk factor for SF in males. It is important to note that among females the BMI values were on the lower range of normal for those with and without MTSS (MTSS group ~19.3 kg/m2, uninjured group ~ 18.4 kg/m2). Second, female athletes with MTSS had an average hip internal rotation of 31.1 degrees compared with an average hip internal rotation of 25.5 degrees among uninjured female athletes.  Finally, males with SF had an average straight leg raise of 60.0 degrees while uninjured males had a higher straight leg raise of 74.3 degrees. The authors did not discuss in detail the amount of training performed by each runner, simply stating that training frequency was not an external risk factor for MTSS or SF.

A lack of flexibility, joint range of motion, or muscle tightness may be important risk factors for sports injuries in general and this paper suggests that they may be risk factors for SF among males (i.e., limited straight leg raise) and MTSS among females (increased hip internal rotation).  In addition to flexibility and range of motion concerns, a higher BMI was also a risk factor for MTSS among females and may correlate with a lack of conditioning, and therefore may place an athlete at greater risk for injury.  However, 19.3 kg/m2 is not a high BMI which raises the question of whether there were other factors leading to more MTSS? For example, an interesting addition to this study would have been to screen for dietary calcium and vitamin D intake, and check to see if any of the runners were vitamin D deficient.  There were a few advantages of this study. First, the authors used a large sample size with a good time interval. Also, they used running athletes as opposed to other studies which evaluated MTSS and SF among military personnel. However, it is unclear if we can use the results of this research study and apply it to our running programs based on possible differences in age, ethnicity and training styles? Lastly, can the results be used for other athletes besides runners? Do your sports medicine departments have a flexibility program and do you screen for flexibility problems as part of your pre-participation physical?
           
Written by: Jill R. Crosson DO, MBA
Reviewed by: Jeffrey Driban

Related Posts:
Yagi S, Muneta T, & Sekiya I (2012). Incidence and risk factors for medial tibial stress syndrome and tibial stress fracture in high school runners. Knee Surgery, Sports Traumatology, Arthroscopy PMID: 22875369

13 comments:

samwalton said...

I think this study is warranted and further studies like it should be done, but I'm a little worried that they didn't examine footwear or training level (intensity, duration, acclamation phases, type, etc.).
With that aside, I'm not really surprised by the results of this study except for the BMI, which they mentioned was a little concerning as it was a normal BMI. This seems to me like a statistical error, or an inappropriate cause and effect finding. But that could be just me being skeptical.

With regard to the questions about flexibility screening and training; this is something that I've done in the past, but not by a departmental rubric. All of our staff utilized sport-specific and self-administered flexibility screening during the PPE process. I have certainly found these useful in injury prevention.

Jeff Morrison said...

I am former high school and college athlete, current high school and college umpire and sports official, as well as a US Army veteran. I have suffered from "shin splints" off and on for 35+ years. I've also dealt with medial tibial stress fractures. I've found four main causes: lack of lower leg flexibility/stretching, improper shoes, running on hard surfaces and being overweight.

I've addressed the lower leg flexibility in several ways: I use a 30 degree wedge slant board to stretch by Achilles tendons/calves twice a day and pre/post-game on game days. I stand on the slant board for 2-3 minutes at a time while leaning forward. I fabricated my own device from 1/2" plywood. It’s light weight, portable and inexpensive. An added benefit is the stretch that it gives my lower back and hamstrings. I also walk on my tip-toes across the room several times. Lastly, I sit on the front edge of a chair with one leg outside of the chair and slightly behind me. I point my toes pointed (Plantar flexed) backwards with the tops of my toes against the floor. In this position, I apply downward pressure for up to a minute at a time, then swap legs.

Proper shoe fit and cushion cannot be stressed enough in prevention and treatment of these issues. Arch support is crucial as well. One factor to consider is that pounding repetition will likely wear out a shoe and/or its cushioning long before the shoe looks worn on the outside.

Hard surfaces and weight control are sometimes a "catch-22" situation. Realize that all aerobic training does not have to be on a court or pavement. Elliptical trainers, bikes and water exercises are excellent alternatives. BMI and weight control should be at the forefront of any exercise or training program.

Longitudinal deep tissue ice massage for several minutes along the lateral edge of the tibia following exercise is also very beneficial. Freezing water in a styrofoam coffee cup makes an excellent therapy tool. Simply take the frozen cup and trim the top edge so that about an inch or so of the ice is exposed. Use the bottom of the cup as an insulating handle.

I also use neoprene compression sleeves that cover my lower legs with great success. I wear them during my training and games. Care should be taken not to wear them too long, as they will trap excess body fluids in the foot area and cause swelling. I would not recommend wearing them outside of training and competition.

NSAID therapy has also served me very well. I personally prefer Ibuprofen since it is inexpensive and doesn’t require a prescription. It’s important to maintain a serum blood level of any NSAID when fighting a lingering inflammation. Simply taking two pills when it hurts does almost nothing to fight the inflammation.


Jill Crosson said...

The comments left brought up a few great points that I think the authors missed in this paper; thank you for the comments. The authors didn't look specifically at training or shoewear. The importance of arch support, proper footwear, training regimen and flexibility are extremely important. Based on flexibility, popliteal angles would have been another factor to add which I think is slightly more specific and clinically useful than straight leg raise. I would have expected the BMI be greater, but it was normal so I agree with the skepticism.

Bethany said...

It would be interesting to find out how training surface plays a role in MTSS/SF. At my high school, we trained on a grass 5k course everyday, except for long runs that we had on a gravel path. We did not have many individuals with shin pain over my four years there. Later, doing my clinical rotation at different high school as part of my undergraduate work, I saw several runners who were experiencing shin pain (both MTSS and SF). The training programs for each of the two high schools were similar, and the only real difference was the the training surface. The high school cross country team at my clinical site ran on the sidewalks every day for practice, rather than grass/gravel.

I am not working with a track/cross country team right now, but I do work with a different running sport: soccer. While we do not have a flexibility program that we implement as a department, I have noticed that my soccer athletes with shin pain have the least flexibility out of everyone on the team. I think that this article is interesting and provides some information that future research should expand to other sports. In addition, future research should consider footwear and playing/running surface as well. Although my soccer athletes always practice on grass, wearing cleats is a significantly different experience than wearing running shoes or even spikes.

jill Crosson said...

Thanks Bethany,
Its interesting to hear about each persons experiences... I think you make a great point. A study like this needs to be done to see if training surface definitely makes a difference. Curious to hear about others experiences. I still think flexibility is very important. Also looking at core strength would be interesting. Thanks for the comments.

Natalie said...

I agree with Bethany; I think training surface plays a huge role in injuries in runners. I think running on a natural surface like grass, dirt, etc just makes so much more sense from an anthropological viewpoint, especially considering that asphalt/concrete are artificial surfaces that we would not normally be running on if not for the expanse of modern urbanization. I don't think the human body was designed to run miles and miles on hard artificial surfaces without sustaining some kind of overuse injury. I know anecdotally, myself and other runners I know are able to run greater durations pain-free when trail running as opposed to road running. It is unfortunate that in some areas running on natural surfaces is not an option, since it has a much lower impact on the body.

Jill Crosson said...

Absolutely agree Natalie. Although running location is another discussion altogether!
If we had easy access to grass paths, maybe we'd have less obesity besides just shin splints!

Alyssa Grell said...

After experiencing shin splits myself, I truly think flexibly wasn't the main cause of mine. As it might be a cause for some victims,I solely believe my shin splits, which then later caused a stress fracture in my tibia. Without a doubt I was the most flexibly girl on my team and somehow I was still experiencing this shin pain, that I continued to play on the entire season. My amount of playing time as well as running did add up to a significant amount, which is why I think overuse was my main trigger. Types of arches would be a good place to study deeper. My functional flat could also not help my case.

Kerri Schmanek said...

There are a lot of factors left out in this study in trying to figure out the risk factors of MTSS and tibial stress fractures in high school runners. Most importantly, I believe that training intensity and whether or not the athlete was conditioned or not (other than BMI) should have been investigated in this study in addition to all of the biomechanical assessments. All sports, not just runners in particular struggle with flexibility, joint ROM, and muscle tightness. That why I believe that an increase in training, ill-fitting shoes, and different running surfaces should have been assessed in order to be more specific to the runner population. Furthermore, I agree with the statement the author made about testing for vitamin D deficiency. Those results could have yielded a different result in the overall study. Lastly, why was all of the injury reporting the responsibility of the coach? It is possible for a coach to not report an injury if they really want that athlete to compete regardless of how the athlete feels.

Jeffrey Driban said...

Hi Kerri:
Thanks for the comment. I agree that training intensity is a very important risk factor for MTSS. This study was mostly looking at baseline risk factors. So when you do your physical screening exam what can you look out for. It was not looking at risk factors that may contribute to MTSS once they start the season. As you point out, it would have been very interesting if they had looked at the level of conditioning the athletes had. Coach- and self-reported injuries are always prone to misclassification but that most likely would have made it harder for the authors to identify risk factors.

Kaitlyn Johnson said...

I found this article very interesting. I am an avid runner and always seem to find myself getting MTSS (shin splints.) I have never thought about how BMI and hip rotation can be a factor with this, I always thought it was a cause of me switching surfaces. This now makes me what to check my internal hip rotation and see if there are any deficits and if that may be a contributing factor. I also found it interesting for men; limited straight leg raise was a significant risk fact for a stress fracture. One thing I would like to see is if these finding also contributed with surfaces changes.

Alexis Bender said...

The variables they measured in this study were very interesting and conclusive. Q-angles, muscle tightness, and flexibility are all key components in MTSS. However I feel that there were a feel flaws in this study. Type of shoe wear, intensity of training, and also the type of terrain they were running on should have been included in this study. Those are some of the largest factors in getting MTSS, and they were not included.

Jeffrey Driban said...

Thanks for the comment Alexis. You are correct that they focused on intrinsic factors that could contribute to stress fractures. It would be interesting to see how these risk factors interact with extrinsic factors like shoe wear and intensity of training. Despite omitting the extrinsic factors I think this does offer some key patient characteristics to look at prior the start of a season. If you have a patient with the intrinsic factors described in this study then you may want to take extra precautions, including closely monitoring things like their training level.

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