Ed Note: The article was published earlier this month at the Ortho Pro website.
Running on dirt is better for your joints, but the uneven terrain of trails can lead to injuries
Trail running gives runners the escape and freedom they yearn for that treadmills, streets and sidewalks don't always provide. But what else does running off-road give you in addition to a psychological and emotional boost? Plenty. In contrast to the harder surfaces, running on dirt offers the least amount of shock on your body, and that can translate into fewer injuries and fresher feeling legs, even with more mileage.
But while running on trails has its benefits, many injuries can still occur. The following are the five most common trail running injuries, as well as why they happen and how they can be prevented.
Knee pain, especially of the kneecap or patella, is the most common problem trail runners experience. If you think going uphill is the cause, think again. Downhill running can produce stresses of five to eight times your body weight on the knee as compared to three times body weight on flats. This makes the knee susceptible, as it is the main shock absorber during your landing.
Prolonged or repetitive downhill running puts increased stress on the kneecap cartilage which can become inflamed causing sharp pain during a run - and even with non-running activities such as going up and down steps or during prolonged sitting.
There are many measures runners can take to prevent knee pain, but the most important is strengthening your quadriceps, specifically with an exercise like the single-leg squat . Other measures include a gradual introduction to hill (especially downhill) mileage and generally slowing your pace when descending the hills to keep the landing stresses as low as possible.
Sprained ankles are another common injury with trail runners. The imperfections of the terrain found on trails - the rocks, ruts, soft dirt and uneven surfaces - can all cause an ankle to land in a precarious position, which could lead to a sprain and then days or weeks of swelling, pain and the inability to run.
Why does this happen? Bad luck has something to do with it, but there are several factors under your control that can prevent ankle sprains.
First and foremost, don't run downhill too fast or with an extended stride where landing occurs on the heel. Your ankle joint and the joint below it have lots of motion, allowing your foot to adapt to uneven ground, while the middle or "ball" of your foot has much less motion and is therefore more stable and less likely to be sprained.
The midfoot strike hitting a stone or rut is less likely to sprain an ankle than the more mobile heel striker landing on the same stone or rut.
The other factor under your control is your center of gravity and how far the foot lands in front of it. If you look at a runner's form from a side view, his or her center of gravity falls through the hips on a straight line to the ground. The closer you land under your center of gravity, the more stable your are. So the longer your stride the further you move in front of the center of gravity, and the more unstable your landing becomes. Concentrate on keeping your feet under your center of gravity and avoid landing on your heels, especially on the downhills, in order to prevent ankle sprains.
Achilles & Calf Strains
Another common injury on trails is an Achilles tendon strain or a strain of the calf muscle lying just above it. This injury can be extremely annoying since the Achilles tendon, the largest tendon in the body, has relatively poor blood flow, which results in a slower healing process. This usually makes an Achilles injury a chronic rather than a short-term problem.
Unlike the ankle sprain, running uphill is the cause of this injury. Many local trails are in the mountains and canyons and involve long steep climbs. Often, runners coming off treadmills and flats don't account for these ascents and trudge up these climbs fearlessly because of their highly developed cardiovascular systems. But, unfortunately, while their hearts and lungs can take the punishment of long climbs, other tissues – especially the ones used to propel their bodies up that hill – have not had a chance to adapt to this new type of running stress.
There are a few tips to avoid a calf or Achilles tendon injury. First, don't be afraid to walk for regular intervals during your initial long climbs. Many times walking a steep hill will get you up in the same time as a slow run.
Second, treat trails as you would running on flats or anywhere else. Introduce distance and difficulty slowly. A 10 percent increase in time or distance, while conservative, is a smart approach.
Third, technique is crucial. If your running style involves a long stride with a push off the big toe far behind your center of gravity, you may be stressing the calf (and its adjoining Achilles tendon) much harder than is necessary. Muscles have optimal positions to produce work, and working your calf far behind your center of gravity (opposite the ankle sprain prevention advice) causes it to work longer than necessary and in a position where it is weaker.
The result is stress on either the muscle or its tendon and possible injury. To prevent this, keep your stride shorter and lift your heel early. Maintaining a higher foot strike or cadence can be one way of doing this. Short, quick strides are safer than longer, slower strides.
Lower Back Pain
Another less common problem with trail running is lower back pain. This occurs with excessive downhill running, especially steep hills, which cause a slight lean backward for better balance to prevent excessive speed. Back pain occurs during downhill runs when your feet strike the ground with greater impact than on flats or uphill runs – upward of five to eight times your body weight with each foot strike.
The lower back in a slightly backward bent position puts your spine and other joints in positions where they are under more compression. When the stress of greater foot impact is added to this posture the stresses on the low back are compounded.
How can this be prevented? Again, shorter strides, landing closer to your center of gravity as well as not running "all out" on the downs will decrease the chance of injury. And, as previously mentioned, let your back adapt to this type of running through a gradual program of trail running.
“Shin splints” are a wastebasket term for any pain in the lower leg, especially on the medial (inner) or lateral (outer) slides of the lower leg. The muscle groups located on both sides of the leg have two primary functions during running – stabilizing and decelerating the foot and ankle during contact with the ground. When do you need the most stability? On uneven surfaces. And when do you need the most deceleration? Downhill. Combine the uneven terrain and steep downhills and you've got a recipe for shin splints.
The solution is to take it easy and limit how hard you run the downhills at least until you're a bit more seasoned on trails and your form and mechanics have improved.
Ortho Pro provides high-quality physical therapeutic services and specializes in the needs of runners. They excel in treating pain and resolving injuries in the fewest number of visits. They also conduct running clinics and assessments of running form, (a must for serious runners).
Traxee personally recommends Jeff Waldberg and Ortho Pro Physical Therapy for their exceptional expertise in getting runners of all ability levels back on the road as quickly as possible. You can visit Ortho Pro on the web and check out their great content, or give call them at 818-865-9800.
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