Wednesday, October 28, 2009

What I've Learned About Stress Fractures

I've been fortunate enough in my years running to have experienced numerous mild injuries, that were enough to gain some personal insight but not so bad that I missed much time running. As they say experience is the best teacher. It is one thing to read about an injury, another to treat numerous people with that injury, and quite another to actually have the injury yourself. When someone comes in with a tight back, sore hip, strained hamstring, or plantar fascitis, I can feel their pain.

Now that I am back running (hallelujah!), and having seemingly fully recovered from my stress fracture, I thought I would share a few new things I have learned:

1. I debated getting a pneumatic boot when the injury first happened. Even though they seem to be the standard of care, the only studies I could find said that they didn't make any difference in healing time (although this was for tibial stress fractures and mine was a metatarsal fracture.) Wanting to avoid any additional muscular atrophy, I decided to just listen to my body and go with what allowed me to get around without pain, which turned out to be a built-up, motion control running shoe I dug out of the closet. I wore these daily for 1-2 weeks until I could transition out of them.

2. In surfing around for stress fracture related info, I came across a product called the Exogen Bone Healing System, "the only bone healing device approved to accelerate fracture healing of indicated fresh fractures." I had heard of using electric currents to facilitate fracture healing, but was surprised to learn that the Exogen uses ultrasound. Ultrasound is basically a vibrational frequency, meaning that the healing effect in this case is thought to come from the mechanical stress induced by the shockwave created. When I learned this it kind of confirmed my decision not to use the boot. My thinking was that if daily ultrasound application (mechanical stress) helped bone healing, then immobilizing it in a boot would almost have the opposite effect. So long as I was putting some stress on the area by continuing to walk on it with shoes that allowed me to do so without pain, I thought I would be accomplishing relatively the same effect. The key I felt was really heeding the pain signal and resting and icing when it felt appropriate.

3. I started taking a calcium supplement (Metagenics Cal Apatite) right from the beginning. This is a higher grade form of calcium called MCHC. I remember seeing a study showing decreased healing fracture times with large doses of MCHC. Most calcium supplements consist of calcium carbonate (the same as TUMS) which don't absorb all that well. I've seen x-rays where calcium carbonate pills are floating through the intestines, undigested.

I don't know if these factors made a huge difference, but I can say that my particular fracture healed to where I could run again within 4-5 weeks, which seemed like a pretty quick turn-around time.

Friday, October 16, 2009

Proximal Hamstring Syndrome

I thought I would talk about a running injury that I have seen a lot of over this past summer and fall. There is a very specific type of hamstring injury that can occur in runners that, once present, can be hard to shake. The official diagnosis is 'Proximal Hamstring Syndrome' or 'High Hamstring Tendonitis' (or Tendinopathy), although, as we shall see, this injury has more to do with the pelvis as a whole rather than just being confined to the hamstrings.

This injury is fairly unique to runners, more often in woman, and especially in woman that have had kids.  (A joke in our office is that our number one patient is the running mom with butt pain.)  Runners with this injury typically feel the pain right up at the crease of the butt, somewhere near the ischial tuberosity (or the "sit bone"), which is the proximal attachment of the hamstrings. Sometimes the pain will radiate down further, leading runners to identify it as a hamstring injury. For other runners the pain is a little higher and will be labelled a gluteal or piriformis problem. When asked to point to where it hurts, the runner will often have a hard time locating the exact spot where the pain originates.

Other relevant structures in the area include the sacro-tuberous (ST) ligament, which merges with the hamstgrings at the ischial tuberosity, the gluteals, the sciatic nerve and the over-lying piriformis muscle. One interesting bit of anatomical trivia is that the hamstrings and ST ligament (along with the back muscles above and the calf muscles and even plantar fascia below) are literally connected by fascia (connective tissue), making them one continuous functional unit. A consequence of this is that tightness anywhere in that chain can pull on other parts of the chain.

The symptoms can range from chronic mild tightness in the area to more severe pain, especially during prolonged driving. In many cases it doesn't hurt to actually run, but more afterwards. The injury may relate to one specific muscle pull, especially during speed work, or just as commonly develops gradually over time with lesser intensities of running.

The tricky part of this injury is that it almost always represents a problem of the hip as a whole, and not just the hamstring. Classically the runner will have weak gluteals and/or tight hip flexors that tilt the pelvis, effectively pulling the ischial tuberosity upwards, pre-tensing the ST ligament and hamstrings. The picture below demonstrates a common postural dysfunction called "Lower Cross Syndrome", where in addition to the weak gluts and tight hip flexors the individual has weak abs and tight back muscles, contributing to a forward pelvic tilt.

My take on Proximal Hamstring Syndrome is that quite often it occurs in runners who demonstrate some or all aspects of the lower cross syndrome; maybe not enough to cause the normal accompanying symptom of lower back pain, but enough to distort the pelvis and preload the hamstrings and pelvic ligaments. Subsequently these structures then become more susceptible to injury. Starting from this basic template, there are different scenarios that can occur:

-The hamstring and/or ligaments can be overtly strained, or torn. This might happen with speed work, or with a forceful, unanticipated stretch, such as getting pulled forward while on water-skis.

-Just as commonly there isn't one specific tear but just continued tension and inflammation that causes adhesions (scar tissue) to become layed down along the upper hamstring and/ or the ST ligament itself. The longer this injury persists the more adhesions form.

-In some cases, the piriformis muscle also becomes involved, causing sciatic nerve irritation and more pronounced pain, sometimes further down the leg.

-I've even had some cases recently of runners where the only symptom was recurring calf muscle pulls. We were able to trace things back to the sciatic nerve involvement which was apparently causing subtle weakness of the calf, making it susceptible to strain.

Many runners self-manage this injury with hamstring stretching, foam roll work, and ice, but find that these remedies don't really make much long-term difference. As a matter of fact excessive hamstring stretching can actually make things feel worse, because you are just further aggravating a pre-tensed muscle. Rest may improve things short-term but the symptoms usually return when running resumes.

As far as treating this injury, most of the underlying factors must be addressed for true long-term resolution of the problem. A lot depends on how long the issue has been present. I've had cases when the runner seeks treatment soon after the pain has developed (before adhesions have developed) where simply releasing the hip flexor and having them strengthen the gluts resolved the problem. More commonly we have to add some cross-friction massage and Active Release Technique to the adhesed ligaments and hamstrings to fully alleviate the pain.

The biggest factor in preventing this type of injury (and many others) is to keep your core muscles strong, especially the gluts. This topic is worth its own blog, but essentially, for runners, I use the single-leg bridge as a benchmark. Being able to hold this position for 5-10 seconds solidly, without wobbling or hamstring spasm, indicates adequate strength for running. If you can't hold this position, do bridges with both legs on the ground, working your way to the single-leg version over time. Long story short, keeping your butt strong help will prevent one less pain in your butt!

Monday, October 5, 2009

Stress Fracture

So as I mentioned last time I believe I have a stress fracture. It happened on a Vibram Five Finger run on the road about four days prior to the Vermont 50K. I started to feel pain which then quickly progressed to where I had to hobble home. Initially I was hopeful that it was along the lines of a mechanical metatarsal issue (see the post Dropped Metatarsal.) I had my friend and colleague Garret Llewlyn, D.C. work on it several times, which alleviated some of the pain, but the remaining pain was on top of the 4th metatarsal and persisted. Pain on the top is quite often indicative of a stress fracture (while pain on the bottom is usually mechanical in nature.)

I haven't gotten an X-ray yet as stress fractures are notorious for not showing up initially. Out of the dozen or so stress fractures we saw this past summer I can only think of 1-2 that actually showed up on the first X-ray (by the way most of these occured wearing conventional shoes.) I'll proabably get one in a week or so just to confirm, and what you would typically see more than a fracture line is the fluffy white evidence of new bone being layed down.

I want to thank everyone for their best wishes. I didn't feel like I was doing anything outlandish with my running, so therefore just have to accept it and move on (what else can you do?) I'll treat this as a learning experience. Fortunately it's not so bad that I can't do some biking so I'm not going completely nuts. (Running up a hill with a cyclocross bike on my shoulder did prove unwise. I'm trying to picture the look I would give to someone in my situation who did that. Physician, heal thyself.)

Anyways the intent of this post was to provide a cautionary tale to those interested in the whole minimalist movement. I still believe whole-heartedly that ultimately that is the way to go. However I can pick out some mistakes I made that led to this, that might help others avoid a similar fate:

1. First and foremost, I realize that a Tarahumara Indian I am not! Meaning that just because I integrated barefoot and Vibram running into my training throughout the summer, I spent most of the rest of my time (not to mention life) in shoes. It takes time for most of us Westerners to adapt the foot and calf strength, and apparently bone density, required to do this safely. When someone suffers a stress fracture, I often use the phrase, "Too much, too soon." This applies here as well.

2. Be extra cautious on the road. This wouldn't have happened had I stayed on the grass. I honestly have never felt better than the barefoot runs I did on grass this summer. There were times where my form felt perfect and I felt like I could have run forever.

3. Additionally, be cautious of using Vibrams on the road. Vibrams take away the skin sensitivity factor of running barefoot, allowing you to open up your stride more, which is something I initially liked about them. On the other hand, they don't really provide any more cushioning that being barefoot. The net effect is that there can be more impact to your foot in Vibrams than when barefoot. I noticed this phenomenon leading up to the injury. Running on a mostly soft surface such as Pineland, Vibrams were perfect, to minimize the ouch of stepping on small rocks, acorns, etc. However on a nice smooth road free of debris my feet were actually more comfortable when barefoot, once I had built up enough calluses.

(This same effect has been observed in conventional, cushioned running shoes. Most of the feedback from your foot is dampened, which can lead to alterations in your gait, such as heel striking, that can actually produce more force than if you were barefoot.)

4. Lastly, I don't think that it was random that it happened where it did. Having Dr. Llewlyn work on the foot right after it happened made me realize the joints nearby were fairly locked-up, which placed more stress on the spot that fractured. Also, I had been sick for about a week leading up to this, and had done a lot of laying around trying to recover. I could feel my gait was off, and in particular that my left foot wasn't springing off the ground like my right (which I associate with the tibialis posterior muscle, which supports the arch.) This is something I had noticed before but had improved as my calves had gotten stronger. I think being sick, and also being barefoot less overall due to colder weather had weakened my left calf just enough to contribute to the injury.

We've all heard stories about people having near-death experiences realizing the preciousness of life. Not to over-dramatize, but it's really hit home for me over the past two weeks what a gift it is to be able to run.