Shin Splints: Part II

As mentioned in my previous post on shin splints, "shin splints" is a very general term which generally refers to symptoms rather than a proper diagnosis. It can be considered an umbrella term, which encompasses a variety of lower extremity disorders related to the tibia. When athletes or coaches find themselves facing "shin splints", a true diagnosis must be made in order to ensure the correct course of action for recovery. Generally, there are 3 distinctive conditions which underlies "shin splints":

1) Medial/Lateral Tibial Stress Syndrome: This was discussed in extensively in my previous post on shin splints. It is the most common form of "shin splints" and generally the least severe. It generally takes 2-3 weeks to heal and chances of recurrence are slim if proper precautions are taken.

2) Tibial Stress Fractures: Often occurs if medial/lateral stress syndrome is not treated soon enough. Chronic impact to the tibia can cause micro-fractures in the bone itself. The diagnosis of tibial stress fractures is often confused with medial/lateral tibial stress syndrome and there are various methods to differentiate the two:

• In most cases, the pain associated with medial/lateral tibial stress syndrome will reside with gradual activity. In the case of stress fractures, the pain will gradually get worse with activity. However, this is not absolute. In some rare instances of medial/lateral tibial stress syndrome, the damage may have progressed far enough to mimic the pain of stress fractures.
• Pain due to stress is supposedly more localized (i.e. you can pinpoint an exact point on the bone that hurts). From my experience this is not always true especially if the fracture is deep in the posterior tibia, the pain can feel quite widespread.
• Physicians can perform a quick test with a tuning fork. A vibrating tuning fork is put against the tibia and if there is a stress fracture, the high frequency vibrations will send a sharp pain through the periosteal nerves. This test may not work if the stress fracture is deep in the tibia (ie under the gastrocnemius and soleus muscles).
• X-ray imaging can sometimes show stress fractures. But often the resolution is not high enough. Some signs such as periosteal thickening can point to healing stress fractures.
• The best test to determine if a stress fracture is present is a bone scan. A radionuclide is injected into the patient's bloodstream. The radionuclide will be localized in areas of high bone turnover (which is indicative of a stress fracture). This is then detected my special cameras that sense the radiation emitted by the radionuclide. The presence of a "hot spot" will pretty much confirm a stress fracture. So why not skip all the above and just jump right to the bone scan? Well it has to do with demand and a lack of resources. Waiting lists for a non-emergency bone scan can be up to a month (especially with the health care here in Canada). Also in places with no universal healthcare and/or individuals with no health insurance, a bone scan can typically cost $500-$700.

The only treatment for stress fractures is rest. Staying off your feet as much as possible (and even casting it) will help speed the healing process. In general, stress fractures take a minimum of 6 weeks to heal.

3) Chronic Exertional Compartment Syndrome (CECS): This is probably the worst of all three conditions because there is currently no non- surgical cure. When the muscles of the lower leg are exerted, they expand against the inflexible fascia of the shank which divides the lower leg into compartments. In some individuals, there isn't enough space between the fascia and muscle to accommodate the expansion. The result is an increase in compartmental pressure which can pinch nerves and cause a numb sensation in the leg. Along with the pain and numbness, CECS can cause a decrease in ankle range of motion (especially dorsiflexion). Once the activity has ceased, the pain will subside when the compartmental pressure drops. This can take anywhere from 10-30 minutes.

Testing for CECS involves sticking a pressure gauge into the compartment(s) of the leg prior to and after exercising. A large spike in pressure points towards CECS. Treatment involves making incisions in the fascia of the compartments to allow more space for the muscles to expand.

A misdiagnosis can waste valuable training time and money. Remember that correctly identifying the problem is the first step to any treatment.

A Biomechanical Analysis of Usain Bolt's 9.58WR

In the Beijing Olympics, Bolt stunned the world with a 9.69 performance. Many believed that Bolt had pushed the sport to its limits and that it was humanly impossible to run any faster. Fast forward to the 2009 World Championships in Berlin, Bolt struck again by smashing his own WR with a jaw-dropping time of 9.58. This begs the question how much faster can a man run? Is there really a physiological/anatomical limit to speed?

Here are some numbers for you (taken from the IAAF site):

	Reaction Time	20m	40m	60m	80m	100m
Time (s)	0.146	2.89	4.64	6.31	7.92	9.58
	0-20m	20-40m	40-60m	60-80m	80-100m
Velocity (m/s)	6.92	11.43	11.98	12.42	12.05

I would throw a graph at you but I'm lazy to make one. But as you can see, Bolt accelerates way past the 60m mark. This is contrary to conventional wisdom, where speed can only be gained up to the 60m mark and then the athlete must "hold" on to whatever speed he or she has attained for the next 40m. Based on wrong assumptions like these, it was not long ago that researchers believed that a sub 10 second time was impossible. However, Bolt (and other sprinters too I should mention) have slowly chipped away at the 10s barrier, with Bolt leading the way.

So, how much faster can he possibly run? Well, looking at the chart above, Bolt had a reaction time of 0.146, which is not very good for his standards. In comparison the fastest reaction time in that race was 0.123 seconds (Dwain Chambers). At 6'5", Bolt's start will undoubtedly be his weakest part of the race. However there is certainly room for improvement. Also, Bolt's prime years are yet to come. I am almost certain that we will see him break his own record again. My prediction is that he will run a 9.5 in the near future. Bolt has redefined the sport and will continue to do so. It is an exciting time for T&F. We'll just have to wait and see how much more this guy can push the human speed limit.

Merritt Update:

ESPN is reporting that the "over-the-counter male enhancement" product which Merritt took was called "ExtenZe", a product claiming to have penis enlargement effects. I can't help but laugh at this one. Looks like Merritt's desire to gain an "inch" on his competition is really going to cost him this time.

Oh no...Not Another One

Breaking news today in the world of track: 2009 world champion in the men's 400m, Lashawn Merritt tested positive for DHEA, an IAAF banned substance. The American has dominated the 400m in recent years, consistently beating out rival Jeremy Wariner.

Here is the press release:

"According to Thursday’s release from lawyer Howard Jacobs, the American used an over-the-counter male enhancement product that contained substances that caused him to fail three successive tests between October and January."

Merritt released the following statement: "As an athlete, and strong advocate of fair competition; I have worked very hard to push myself to the outer limits of my physical abilities without any performance enhancement drugs. I’ve always prided myself on doing what’s right, and will continue to do so. o know that I’ve tested positive as a result of product that I used for personal reasons is extremely difficult to wrap my hands around. I hope my sponsors, family, friends and the sport itself will forgive me for making such a foolish, immature and egotistical mistake. Any penalty that I may receive for my action will not overshadow the embarrassment and humiliation that I feel inside.

I am deeply sorry and hope that other athletes who take these types of over the counter products will be even more cautious and read the fine print, because if it can happen to me, it could happen to you.”

This all sounds very suspicious. How many times now have athletes claimed to "unknowingly" take a banned substance? Frankly it's lame and inexcusable.

FYI: DHEA stands for Dehydroepiandrosterone. It is available OTC in the USA (here in Canada you need a prescription). DHEA is abused by some athletes for its ability to block the body's natural cortisol levels from breaking down lean muscle mass. Training induced stress greatly elevates serum cortisol levels and DHEA acts by countering this increase, thus creating an "anti catabolic effect".

Merritt is currently suspended from competition while his case is further investigated. Regardless of whether he is allowed to compete or not in the future, his career will probably be tainted forever due to this revelation.

A Runner's Nemesis: Shin Splints

What are shin splints? The term "shin splints" is a general term associated with sore shins either on the inside of the shin bone (tibia) or on the outside. The proper medical diagnosis for pain along the inside surface of the shin bone is "Medial tibial stress syndrome (MTSS)". This is the most common form of "shin splints".

So, what exactly causes MTSS? Well, there is no short answer. The current consensus is that MTSS is caused by the inflammation of the periosteum. Wait a second...the peri what?. Ok heres some basic anatomy:

We (most of us at least) know that muscles originate from some bony landmark on one end, and insert into another bony landmark on the other end (usually via a tendon). Between the origin and insertion, the muscles are also connected to their respective bones via a thin layer called the "periosteum" (if not then our muscles would dangle around!). Sometimes when muscles are overused or subjected to extensive impact forces, micro tears can form in the periosteum,essentially displacing the muscle from the bone. The body's natural defense system kicks in and causes the periosteum to become inflammed.

In the case of MTSS, two muscles have been associated with this condition. The soleus muscle and the tibialis posterior muscle attach on the distal end of the tibia (2-4 inches above the ankle). Exercises involving lots of running or jumping places alot of stress on the muscle-bone interface. The constant pounding of the lower extremities can result in MTSS, with symptoms including pain and tenderness. Many other factors could underlie or amplify the problem, with the most common ones being:

1) Biomechanical issues. When we strike the ground, our feet are designed to "pronate" which means to roll inwards. This helps with dampening the impact upon footstrike. Some runners, especially those who have naturally flat arches "overpronate" (ie have the foot roll too much inwards). When this happens, a tremendous amount of strain is put on the muscles.

2)Running on hard surfaces. This mostly applies to distance runners who run on concrete or hard trails. The harder the surface, the larger the impact forces.

3) weak soleus or tibialis posterior (more likely) muscles. Weaker muscles don't dissipate impact forces as readily and therefore more strain is put on the muscle and its periosteum.

Like with most inflammatory injuries, warm up and gradual activity will cause the pain to subside. However, the pain relief is only temporary and exercising through MTSS is never the right treatment (take if from someone who had to learn the hard way)

So thats MTSS is a nutshell. The good news is there are ways to prevent or treat MTSS. The general rule is the sooner you recognize the condition and treat it, the more effective the actual treatments will be. So don't ignore those stubborn pains, even if you can run through it! Stay tuned for information on how to treat MTSS and for my experiences with this runner's peeve.

A New Beginning

Athletes strive to get fitter faster and stronger. No sport exemplifies this more than track. This blog is dedicated to everything track and field: training tips, workouts, news, nutrition etc.

Cheers to a healthy lifestyle and the up and coming PBs.

I'll leave you with this video. I get goosebumps every time I watch it