Running Faster May Not Cause Shin Splints

Frequent site of shin pain/ stress fracture

We runners have always been told to train and don't strain. Running too fast, too often, can be a sure recipe for injury. That's why we always have an easy day for recovery after a hard session, to reduce our risk of injury. No runner wants to hear that they have a stress fracture or a small crack in their bones caused by overuse.

We think that when we run faster, we put more strain and load through our muscles and bones. So chances of a muscular or bone stress injury should be higher when we run faster.  We all assume that running slower (or slowly) causes less strain on our legs than running fast.

According to newly published research, fast paced running does not put any more pressure on your tibial (shin bone) which is a common area for shin splints and stress fractures than slow easy runs.

Runners in that study were asked to run at their own selected pace of slow, moderate and fast (but not all out). Reflective sensors were attached to their hips, knees and feet while they ran over force plates that measured impact (load) with each step.

I was really surprised to read that the slow paced runs (and not the fast runs) resulted in the most strain. Running at 'normal' or moderate pace for these runners caused less cumulative load than running the same distance at fast and slower speed.

The authors concluded that running fast does not necessarily cause more load on your tibial (shin bone) than slow running. Well, no excuse not run intervals once a week then if you're training for a race.

However, it may be too early to use this information to change our training habits as fatigue definitely does affect load when we run. Personally, I do feel I need an easy day of training to recover after a hard bike, run or weights session. Even when I was competing, it's usually 2 hard days of training back to back with a easy day (or total rest day) after. That way you won't have to worry about getting injured. Until an an accident strikes ......

Reference

Hunter J, Garcia GK, Shim JK et al (2019). Fast Running Does Not Contribute More Cumulative Load Than Slow Running. Med Sci Sp Ex. 51(6): 1178-1185. DOI: 10.1249/MSS.0000000000001888

Shin Splints Back In 1415!

R shin(top) shows obvious wear

I had a runner who came to see me this week. She had recently done a marathon in Australia and recently got back to training again after a break. She said she had been asking a fellow runner with shin pain to come see me. This friend of hers had been suffering from shin splints for the past six months!

Just in case you thought that was long. I saw an article that showed a case of documented shin splints from way back in the year 1415. Yes, you read correctly, it's 1415.

Researchers found a skeleton from a graveyard in Greece that showed medial tibial stress syndrome (or shin splints). They estimated that the man died between 500-800 years ago and was between 20-30 years old.

The researchers mentioned that shin splints are commonly thought to be an exercised induced injury. and that shin splints are most common in new runners.

Osteoarthritis in the ankle

The skeleton also showed signs of osteoarthritis in the ankle joint (which is rare); this suggest that the man probably engaged in some repetitive loading of his lower limbs. An indication that perhaps even in those days they participated in running as well.


Reference

Protopapa AS, Vladchadis N et al (2014). Medial Tibial Stress Syndrome: A Skeleton From Medieval Rhodes Demonstrates The Appearance Of The Bone Surface- A Case Report. Acta Ortho 85(5): 543-544. DOI: 10.3109/1753674.2014.942587.

Beach Running Anyone?

I have patients who get impact associated injuries like shin splints or stress fractures all the time. it's probably the most common running injury we see in our clinics along with knee pain.

Other than deep water running which has no impact, I often suggest going to the beach to get them running again.

Have you tried running on the beach? Research shows that running on sand requires 1.6 times more energy expenditure than running on a firm surface. Try it to believe it. Due to the change in technique you require as well as balancing on the sand, the stabilizing muscles in your hips, knees and ankle are working much harder.

Soft sand is particularly difficult while hard or packed sand (near the edge of the water) is definitely easier to run on. It definitely works different muscles (compared to running on the road) and it requires more focus so you don't sprain your ankle due to the uneven surface and constantly shifting ground.

In fact, while combating the "slip" element, range of motion of joint angles around the hip, knee and ankle were found to similar to running during faster speeds on firm ground (Binnie et al, 2013). That translates to a much higher heart rate, increasing your oxygen debt and blood lactate levels. Meaning you get fitter, stronger and faster quicker.

So incorporating sand running into your training can definitely help improve your race times.

Another article found that soft sandy surfaces reduced muscle soreness and fatigue (Binnie et al, 2014) due to almost four times less impact versus a firmer surface. Because of the softer surface, there's also less stress on our joints which can lessen impact and helps prevent injuries.

When running on firm ground, less of the elastic energy which is stored in our tendons is absorbed, so you don't have to work as hard. When running on sand, it absorbs the forces, meaning you have to generate more forces with your muscles to run.

Researchers found that there was almost four times less impact forces on soft sand compared to firm ground with every single foot strike. This is really good if you need to reduce load through the legs but still want to get in a hard workout when you run. 

Research also suggest that runners who ran on the beach (especially on soft dry sand found farther away from the water) had less muscle damage and inflammation compared to running on grass (Brown et al, 2017).

Due to where I stay, I hardly get to run barefoot on the beach. When I do, which is often during our family's holiday trips, I always start much slower than my usual runs. I also do not worry about the time or distance that I clock. In fact, I often do some short hard sprints (because of the lower impact) to get my heart rate up even higher.

Hearing the waves crash also helps to calm and clear my mind, which is a nice bonus.


References

Binnie MJ, Dawson B et al (2014). Effect Of Sand Versus Grass Training Surfaces During An 8-week Pre-season Conditioning Programme In Team Sport Athletes. Eur J Sp Sci. 32(14): 1001-1012. DOI: 10.1080/02640414.2013.879333.

Binnie MJ, Peeling P et al (2013). Effect Of Surface-specific Training On 20-m Sprint Performance On Sand And Grass Surfaces. J Strength Cond Research. 27(12): 3315-3520. DOI: 10.1519/JSC.0b013e31828f043f.

Brown H, Dawson B et al (2017). Sand Training: Exercise-induced Muscle Damage And Inflammatory Responses To Matched Intensity Exercise. Eur J Sp Sci. 17(6): 741-747. DOI: 10.1080/17461391.2017.1304998

Lejeune TM et al (1998). Mechanics And Energetics Of Human Locomotion On Sand. J Expt Biol. 201: 2071-2018.

Stress Fractures In Teenage Female Runners

Icing the shin

The Singapore National School's competitions are usually held between March and late May every year since 2009. And it's that time of the year again where we see many patients in our clinics with shin splints. Mostly adolescent and teenage girls and the occasional boy.

Why are girls more susceptible to shin splints and stress fractures? Well, some new data shows that if teenage female athletes don't eat enough to support their training, there will be complications regarding their subsequent training and health.

The study tracked 323 female athletes at Stanford University in 16 different sports including cross country running. Bone scans and questionnaires were used to assess the runners based on the components of the "female athlete triad" consisting of "low energy availability, with or without disordered eating, menstrual dysfunction and low bone mineral density. "

Risk status were calculated based on an article published in the British Journal of Sports Medicine  in 2014. Have a look at Figure 4 in the article if you're keen to know more about the calculations.

Looking only at the cross country runners (47 runners) data, half the runners were classified as low risk, and three of those later developed stress fractures.

Sixteen of the runners had moderate risk and 50 percent of these developed stress fractures within a year. These girls were about four times as likely to get injured compared to the low risk group.

Seven runners were in the high risk group and five of them developed stress fractures. They were nearly six times as likely as the low risk group to get injured.

Well, if you're thinking like me, not so good news for the girls if you're a runner and in the moderate to high risk group.

The researchers suggested the following guidelines for female athletes in the moderate to high risk group. The athletes need to ensure they're getting enough calories to support their training along with calcium and Vitamin D. Their menstrual function, bone health and nutrition needs to be monitored on an ongoing basis.

Higher risk athletes may have to consider using low impact cross training more often in their weekly routine. Good sleep and recovery are important too.

Stress fractures occurred mostly in the foot for the low risk athletes, probably as a consequence of biomechanics and jumping sports (due to higher forces).

In the higher risk categories, many of the stress fractures were in the sacrum, pelvis and femoral neck (where the bones tend to be softer). These areas may be due to weakened bone rather than biomechanical forces.

So all the doctors, physiotherapists, physical education teachers, coaches, heads of departments and administrators in charge of female teenage athletes reading this post, please take note.

Reference

Tenforde AS, Carlson Jl et al (2017). Association Of The Female Athlete Triad Risk Assessment Stratification To The Development Of Bone Stress Injuries In Collegiate Athletes. AJSM. 45(2): 302-310. DOI: 10.1177/0363546516676262.

Shin Splints Most Common In New Runners

Picture by Anne Sophie from Flickr

Latest published  research indicates that shin pain is the most common complaint among new runners. Shin splints or stress fractures is also our most popular article in this blog with over 200 comments and counting.

The researchers studied 933 new runners for a year to see how many were injured, what injuries they had and how long it took before they resumed running. They were considered new runners if they haven't run more than 10 kilometres the previous year. The runners were considered injured if they had running induced pain in their legs or lower back that prevented them from training (distance, duration, pace or frequency) for at least a week.

254 runners were injured during their first year of running. 15% of this injured runners had medial tibial stress syndrome (or shin splints), 10% had knee pain, 7% injured their Achilles tendons while 5% hurt their plantar fascia or soleus (deep calf muscle).

Stress fractures were relatively rare, probably because the new runners' mileage in their first year were not high enough. 75% of the injuries happened during the runner's first 201 kilometres.

Time to heal varied widely amongst the injured runners.Those who hurt their calf resumed training after 30 to 40 days, while those with shin pain took an average of 72 days to fully recover. The worst were those who had plantar fasciitis, it took an average of 159 days to recover.

Majority of the 254 injured runners recovered fully (220) by the end of the year long study. Only 34 remained injured.

The researchers concluded that their findings emphasized the importance of the need for new runners to be mindful of shin splints as it is most common injury in their study. Even among recreational and elite runners, shin splints was the most common injury with an incidence of 13-20% (Lopes et al 2012).

Wanna run pain free? Have a read here.

References

Lopes AD, Hespanhol Junior LC et al (2012). What Are The Main Running-related Musculoskeletal Injuries? A Systematic Review. Sports Med 42: 891-905.

Nielsen RO et al (2014). A Prosepective Study On Time To Recovery In 254 Injured Novice Runners. PLOS One. DOI: 10.1371/journal.pone.099877.

Even Kobe has shin pain. (Picture from Flickr)

Shin Splints Or Stress Fracture?

I've seen quite a few of my patients recently with shin pain so I thought I'd write about it. This condition can usually be caused by any activity that involves running, jumping or even extended periods of walking. Patients usually present with pain at the beginning of exercise. During the initial phase, the pain may disappear during the warmup or after 15-20 minutes of exercise, but returns for several hours after exercise. In the more severe cases, pain is usually present during training and aggravated during daily activities like walking, squatting or climbing stairs. There is often pain at rest as well. The pain is often described as a dull, aching discomfort of varying degrees of intensity.

Left untreated, it can progress to a stress fracture in your tibia (or shin bone). Which is exactly what happened to one of my patients.

The picture shown above is the x-ray of my patient's stress fracture. The arrow depicts the callus formation of thickening of the bone indicating a stress reaction in the bone. Usually a bone scan is needed to detect a stress fracture as an x-ray only picks up the callus formation (about a month later) as the bone is healing.

The term "shin splints" refers to pain along your tibia and this is usually caused by too much pulling of your muscles along their attachments along the bone. Research has shown that it is usually the tibialis posterior and soleus muscles that causes this condition. With repeated pulling (or stress), this causes the shin bone to be irritated and pain results. That is why this condition is also known as medial tibial stress syndrome. Milder cases are treated fairly easily. Most physiotherapists will ask their patients to rest, ice the painful area, change footwear and modify your training routine to prevent shin splints from recurring. The cause of your pain should be addressed rather than just treating the shin pain alone.

Most of the time shin splints occur from overuse. It is commonly seen in athletes who suddenly increase their duration or exercise intensity of training. Overpronation is often listed as one of the common causes of shin splints. Now if you've been following our blog article Pain Free Running or running with the Physio or Sports Solutions team, then you will be happy to know that you can run pain free and even avoid getting shin splints. Our athletes with shin splints or stress fractures often do their rehabilitation in the pool as well to maintain their fitness.

I have had stress fractures in both legs before, early in my racing days, when I was just competing in track and field events. This was before I started competing in triathlons of course. I know exactly how frustrating it can be not being able to run. Will be most willing to help if you need any advice on this.

Please read this for more on shin splints.

Reference

Thacker SB, Gilchrist J, Stroup DF and Kimsey CD (2002): The prevention of shin splints in sports: a systematic review of literature. Medicine and Science in Sports and Exercise 34: 32-40.