Slide Your Way To Fewer Running Injuries
Distance running has a higher injury rate than most other sports. How high? Consider the results of a recent Dutch study, in which more than 700 participants in the Rotterdam Marathon were surveyed about injuries suffered during the process of training for the event and within the marathon itself. Nearly 55 percent of the respondents reported suffering at least one running-related leg injury within the preceding year, and 18 percent developed an injury during the marathon itself.
The causes of individual running injuries are often multiple and complex, but most of them involve a lack of adequate stability in a particular joint. When one or more muscles responsible for stabilizing a joint are abnormally weak or are not properly activated during running, that joint is likely to move out of its proper alignment as impact forces travel upward through the body from the ground. This unwanted movement may cause tissue stress or strain within that joint or elsewhere along the kinetic chain. As the foot strikes add up, so does the tissue damage, until eventually the runner experiences the pain and dysfunction that define an overuse injury.
Strong Hips Are Key
Among the most common sites of instability is the hip. To learn why, try the following experiment. Stand on your right foot for 10 seconds. As you struggle to maintain your balance, think about which direction gravity is trying to pull your body. To the left, correct? That’s because your balance point is on the right side of your body—specifically, where your right foot meets the ground—while your center of gravity is at the center of your body, to the left of your balance point.
A stone statue in this position would indeed topple to the left, pivoting from the bottom of the foot. But as a flesh-and-blood human being with movable joints, you will tend to break to the left not from the bottom of your foot but instead higher up the kinetic chain, at the ankle, knee or hip.
Because it is the farthest joint from the ground among these three, and because it has to support more body weight (that of your entire trunk) than the other two, the hip is the joint that is most likely to lose stability when you’re standing on one foot. It’s also the joint that is most likely to lose stability when you land on one foot, as you do repeatedly when running.
Certain muscles—particularly the tensor fascia latae on the outside of your hip and the gluteus medius connecting your buttock to your upper thigh—are responsible for keeping your pelvis in a neutral position parallel to the ground during the ground contact phase of running. If these muscles are abnormally weak or not activated properly, they will allow the pelvis to tilt laterally toward the unsupported side of your body (a slight lateral tilt is natural, but a severe tilt is not). This will put tension on your iliotibial band, which runs along the outside of the thigh from the hip to the knee, and pinch your groin. It will also increase the amount of torsional strain on the knee of the supported leg.
Recent research has shown that runners suffering from patellofemoral pain syndrome (the single most common running injury) and iliotibial band friction syndrome are significantly more likely to exhibit dysfunction in the hip stabilizers of the injured leg than are non-injured runners. Consequently, physical therapists in the know are increasingly prescribing exercises to strengthen the hip stabilizers, such as side lying leg raises, to help runners prevent the recurrence of such injuries.
Another technique that some physical therapists are now using to achieve the same objective is gait retraining. In runners with weak hip stabilizers, there is a tendency for the thigh to rotate inward during ground contact as a maladaptive way to maintain a degree of stability. Irene Davis, Ph.D., who heads the University of Delaware Running Injury Clinic, teach runners to actively contract their hip stabilizers from the moment preceding footstrike through the end of ground contact phase to prevent lateral tilting of the pelvis and internal rotation of the thigh.
Slideboards Target The Hip Stabilizing Muscles
In addition to corrective strengthening exercises and gait retraining, there’s a third way to improve the function of the hip stabilizers that I stumbled upon in my efforts to overcome a nagging case of patellofemoral pain syndrome: the slideboard. A slideboard is a long, rectangular plastic exercising surface upon which a person slides back and forth between bumpers positioned at either end while wearing special fabric booties, thus simulating a skating motion.
Slideboards are indeed used most commonly by speedskaters and hockey players. I bought one after reading the research about the connection between hip stabilizer weakness and running injuries that I just described and scouting around for a good form of exercise to strengthen these muscles, which the slideboard most certainly is.
There are various uses for the slideboard, but I’ve focused on two. I’ve used my slideboard for both hip stabilizer strengthening and aerobic cross-training by performing 20-minute, moderate-intensity sessions on it five evenings per week. The results have been good. I’ve been almost completely injury-free since I began using it a year ago and I set a 10K personal best a few months ago at the age of 36.
Although the slideboard can be used for cross-training, I would recommend you use it primarily as a way to strengthen your hip stabilizing muscles. Most slideboards have adjustable bumpers that may be set at various widths. The farther apart you set them, the more force you have to exert to slide from one to the other, and the greater the strengthening effect you’ll get. Slideboards also come in various sizes (eight-foot and ten-foot lengths being the most common); naturally, the longer ones allow you to slide farther and are therefore better suited to strengthening objectives.
Start Out Easy And Build
A little slideboarding will go a long way if your main or sole objective is hip stabilizer strengthening. I recommend doing three five-minute sessions per week, which you can incorporate into a whole-body strength workout. Be cautious in the beginning. In our seated society, neither the hip abductors on the outside of the hip nor the hip abductors on the inner side of the upper thigh get much use, which is the reason they tend to be weak in so many runners and triathletes. But these same muscles serve as the prime movers on a slideboard, so you have to ease them into it.
I was fully aware of the need for caution when I started using my slideboard, so my first session lasted just two minutes. Nevertheless, my hip abductors and adductors were very sore the next day. I have no reason to believe that these muscles were any more atrophied in me than they are in the next person, so I encourage you to start very slowly with slideboarding as well.
Your slideboard can also give you a good run-alternative workout when an injury prevents you from running, and whenever a sore spot indicates that running is not a wise thing to do on a given day. You’ll want to set the bumpers closer together than you do for your strengthening sessions on the slideboard. Emulate as closely as possible the duration, intensity and structure of the runs you’re replacing with these run-alternative slideboard workouts. For example, if you had planned to do a set of 5×1 km track intervals in 3:45 with 2:00 jogging recoveries, then instead do 5×3:45 at an equivalent heart rate (minus 5-10 beats per minute due to the smaller amount of active muscle tissue) on the slideboard with 2:00 active recoveries between a warm-up and a cool-down that also match the duration and intensity of your track workouts.
Although common, running injuries are not acts of God. Most of them are preventable. Slideboards are an unusual but effective tool to prevent many of them.
Matt Fitzgerald is the author of numerous books, including 80-20 Running: Run Stronger and Race Faster By Training Slower. He is also a Training Intelligence Specialist for PEAR Sports. To learn more about Matt visit www.mattfitzgerald.org