Friday, July 24, 2015

Loss of leg coordination while running as a task-specific focal dystonia distinct from runner's dystonia: an executive summary of findings


Loss of leg coordination while running as a task-specific focal dystonia distinct from runner's dystonia
An executive summary of findings on loss of leg coordination while running

John Davis


 Loss of leg coordination while running is the working term for a rare neurological problem that occurs in long distance runners.  It is characterized by a gradually increasing sensation of tightness, weakness, and poor coordination in the muscles of one leg that occurs only while running—stopping to walk or stand still all but eliminates the symptoms.  Runners with loss of leg coordination cannot point to a specific area of pain; rather, there is a more general feeling of tightness, vague aching, and an overwhelming sense of something being "off" with the functioning of the affected leg when they run.  Further, classic signs of neurological injury, like numbness, shooting pain, or a "pins and needles" sensation, are absent.

These symptoms are also highly specific to running.  Other activities, even cyclical and highly aerobically demanding ones like using an elliptical or riding a bike, do not reliably recreate the symptoms.   The loss of coordination sensation is typically localized to the muscles which are the prime movers of the legs: the calves, the hamstrings, the quadriceps, and the gluteal muscles.  Despite the weak, uncoordinated sensation while running, absolute muscular strength is normal. 

In most cases, running longer, faster, and on flat surfaces exacerbates the problem.  Some runners find they lose coordination with any kind of running, but most are able to run at an easy pace on rough terrain (e.g. on trails or over cross-country).  Short intervals of fast running are not usually a problem, but longer intervals at fast speeds and especially fast continuous runs and races bring on loss of leg coordination more rapidly.  Ceasing a run makes the loss of coordination sensation go away almost immediately, but some lower leg muscular tightness can persist for a few days after a particularly bad episode.

Searching for answers on loss of leg coordination while running: a comprehensive review



This is an extremely long article.  For a shorter executive summary, click here to read in your browser, or click here for a printable PDF version.


 Most of the injury articles on this website are long, detailed, and rigorously cited, with their claims being supported by solid scientific evidence.  Although this, too, is an injury article, it is not like the rest.  The topic of this post is a rare and frightening phenomenon that I and others have tentatively termed "loss of leg coordination while running."  This is an "injury" of sorts that has affected me and, as a very long thread on LetsRun.com has made me aware, many other runners.

Because medical and scientific literature on this problem is scant, much of what follows is based on reports from runners with loss of leg coordination and logical inferences from what's known about how the body works it is running correctly.  Because of this, you should view everything I have to say below with skepticism, especially because I'm not an unbiased writer (having suffered from this problem for quite a while before recovering). 

I told myself I would write this article when I was able to run 50 miles per week again with some faster running.  That point came and went a long time ago—it was far easier to get distracted by my own running again, but it's long past time I write this article.

The working definition of loss of leg coordination is something that I've come up with by analyzing as many descriptions of the problem as I can find.  Much, though not all, comes from posts on the LetsRun.com thread. 

Put in its most universal terms, "loss of leg coordination while running" is characterized by a gradually increasing sensation of tightness, weakness, and poor coordination in the muscles of one leg, but only while running—stopping to walk or stand still lessens the symptoms.  There isn't pain, per se, just tightness, vague aching, and an overwhelming sense of something being off.  And the sensation of losing coordination isn't localized to any precise area; rather, it is associated with a more general feeling of your leg not doing what you want it to do.  It feels like your stride is just "off," like your leg just won't go.  Instead, it flops along uselessly. 

Further, these symptoms seem highly specific to running.  Other activities, even cyclical and highly aerobically demanding ones like using an elliptical or riding a bike, do not reliably recreate the symptoms.   The loss of coordination sensation is typically localized to the muscles which are the prime movers of the legs: the calves, the hamstrings, the quads, the calves, and the glutes.  Some people find that the tightness and poor coordination progress from one muscle group to another as the problem worsens, but there isn't any distinct pattern to this.  Some posters find that their problems start in their feet or ankles and progress upwards, while others have issues in the thigh and calf only.  Though these muscles feel weak and uncoordinated when you run, you can head into the weight room and do just as much weight on hamstring curls, leg extensions, and single-leg squats on your "bad" leg as you can on your good one, so there is no frank loss of muscular strength.  Though this initial wave of symptoms might sound similar to a nerve problem like sciatica, there is not usually any numbness, shooting pains, or "pins and needles" feelings like you would expect with a nerve problem. 

Certain running conditions also exacerbate the problem.  Running faster magnifies the degree to which coordination in the leg is lost, with high speeds resulting in the leg seeming to flop around uselessly, while the opposite leg (the healthy one) picking up the slack.  Puzzlingly, flat, even surfaces like tracks, roads, and treadmills bring on symptoms to a much greater degree than uneven terrain like trails or grassy cross country courses.  Some runners describe being able to complete very long and challenging runs or workouts without any problem on rough terrain, but being completely unable to run any faster than a slow, easy pace on flat surfaces.  Other runners are able to run at an easy pace, but cannot complete any workouts involving faster running.  Some experienced problems at virtually any pace, though faster running on flat surfaces certainly magnified the issue.  Stopping makes the loss of coordination sensation go away almost immediately, but some lower leg muscular tightness or "off-ness" can persist for days after a particularly bad episode, even if you aren't running on the following days.

Further complicating the diagnostic puzzle is the fact that continuing to train with loss of leg coordination often causes a slew of secondary injuries because of the abrupt change in stress on the body.  Several runners reported foot, knee, and hip injuries that occurred concurrently.  In my case, I suffered a sacral stress fracture.  The people with this problem also have the usual smattering of Achilles, plantar fascia, knee, and shin issues that are common in regular runners. 

Add on top of that all numerous health-related idiosyncrasies ("I get tingling sensations in my left elbow," "If I flex my hamstring on my bad leg for a while, it cramps up," "I tore my hamstring playing hockey when I was 12 and have a lot of scar tissue"), plus the rarity of the problem, and you've got an incredibly difficult to diagnose issue.  It's not even clear that all or even most of the people posting about this issue online even have the same problem. 

Doctors, physical therapists, chiropractors, and any number of other medical professionals seem unable to pin down the problem.  Some of the posters report seeing dozens of different doctors and spent thousands of dollars yet coming back empty-handed.  MRIs, nerve conduction studies, and other diagnostic tests either come back clean or identify fairly common issues that are often asymptomatic, like a herniated lumbar spine disc.  Runners report that physical therapists and chiropractors inevitably find muscular weakness or tightness, often in the hip muscles and hamstrings, but they report that their rehab exercises have, at best, very limited and short-term success.

Saturday, July 11, 2015

Running specialization for young athletes: when should you become a year-round runner?


As my bio states, one of my areas of interest as a coach and writer is long-term development for young athletes: what is the best way to take a talented young runner and maximize his or her ability, both in high school and college/beyond? I've been thinking a lot recently about the idea of specialization—at what age is it appropriate or optimal to become a full time distance runner who trains year-round instead of doing other sports?

Perhaps eight or ten years ago, opinion in the running community leaned pretty heavily towards early specialization.  AAU track meets were (and to some extent, still are) popular for runners in elementary and middle school, and high school cross country programs saw a lot of growth in numbers when they started integrating a middle school "feeder program."  In the past few years, however, it feels like momentum is swinging back towards not having runners focus exclusively on running until a lot later—continuing to be multi-sport athletes throughout all of high school, in some cases.  I think the genesis of this was the success of runners like Grant Fischer, who played soccer up until his senior year of high school, plus backlash against hyper-early specialization in big-money sports like football and hockey, where training can completely take over your life, even at a young age. 

Coaches pushing ever-younger kids into two, three, or four-hour daily practices, plus the pressure of performing well at such an early age, can have some real negative consequences on enjoyment of the sport for a young athlete.  At the same time, missing out on too much of the fundamentals will definitely put you at a technical disadvantage, at least temporarily, compared to your competitors. 

This is true for most team and skill-based sports, but what about running? As distance runners, we trade in technical proficiency for raw physiological fitness, and because our sport is a repetitive, high-impact one, we can't put in long hours of training at a young age like swimmers or lacrosse players can.  The typical middle school or high school runner runs cross country and track, perhaps doing a bit of summer running before cross country, but does not train at all over the winter.  Maybe he or she plays basketball, swims, or does indoor soccer.  At what point should we encourage a promising young distance runner to fully commit to the sport? And are there any disadvantages to dedicating yourself to distance running at an early age?

When is the latest you should commit to year-round running?

There's no denying that having a strong lifetime mileage base is important in distance running.  The age of the top runners in the world for each event is proportional to the race distance: The best 1500m runners are 23-24, the best 5k and 10k runners are 26 to 28 years old, and the best marathoners are often in their thirties.1  The older you get, the more lifetime training you can accumulate, and the stronger your aerobic system can be. 

Additionally, a particular race distance has a certain minimum level of training that is required to in order to run it well.  Barring a few supremely talented exceptions, nobody runs a great 10k off thirty miles a week.  The question for the high school runner, then, is "How many consecutive training cycles are required to reach an adequate training level for 5k cross country and 3200 meters?"