Exercise Injury Prevention

Running in the Fast Lane | Listening to your Body | Training Errors Training Principles | Practical Training | Psychological Factors

What is Normal When Listening to Your Body?

It's not always easy to listen to your body because the messages are sometimes unpleasant. There are mornings when simply getting out of bed seems a struggle, a bad idea, with small aches and pains in joints, tendons, and muscles. Anatomically, that's the cost of aging. Maturity brings reductions in joint flexibility, elastic tissue, tendon blood flow, muscle mass, and bone mass. Growing older challenges a "just do it" philosophy, yet the available evidence suggests that is exactly what should be done. Certainly, aches and stiffness shouldn't be ignored, but it's important to sort out pain symptoms that signify injury from those which are the normal consequences of an active lifestyle. That is, it's necessary to listen for the different voices of aches and pain in your body.

As depressing as they first feel, normal aches tend to vanish with activity. They shouldn't be an excuse to skip a workout. Minor stiffness that resolves with motion is also common and not necessarily indicative of a musculoskeletal problem. Likewise, a mild grinding or "crepitus" in a joint like the knee is often present in healthy adults, and does not usually signify a major problem unless the roughness is accompanied by pain, swelling, decreased range or motion, or pain was present for a half hour or more following the activity. In these cases (or anytime a problem is persistent), appropriate medical evaluation and treatment should be sought.

The reason a mild roughness under the kneecap might be present without pain is due to the way that the joint is constructed. The cartilage that is under the kneecap is thicker than anywhere else in the human body. This thickness is a good design because significant forces are generated under the kneecap; the thick cartilage assists with the dissipation of these forces. Over time, some wear and tear often occurs; however, the wear is "a normal part of aging...we all have it if we survive past the age of twenty-five," according to Rheumatologist, Dr. John Bland. You can feel this mild grinding sensation by placing a hand on your kneecap as you straighten your leg. The reason this usually doesn't hurt is that cartilage lacks nerves to send pain signals to the brain. If, on the other hand, the wear and tear becomes excessive or other problems, such as tightness or muscle imbalances, result in abnormal alignment of the kneecap, excessive forces may be transferred to the underlying bone. Bone has a robust nerve supply, and when irritated, will inform the brain of a problem in the form of pain. As such, pain is really a beneficial thing, since it tells us when something isn't working in an optimal fashion.

How about wear and tear on joints? Will exercise accelerate this process and destroy the joint? Do activities like running cause the most common type of arthritis? According to Dr. Bland, "In a word, no." In over ten years of studies, medicine has not been able to establish a clear link between running and arthritis. In fact, the opposite is true. As Dr. Bland points out, "Exercise is the key to keeping tendons, ligaments, and bones strong". These are all structures that are affected by aging, and the exercise stimulus helps maintain these tissues at a functionally younger state. By contrast, "Complete immobilization of a joint for as short a time as three to four months will totally destroy a joint," he explains. That is, the evidence to date suggests that the common "use it or lose it" adage fits for our joint structures.

This isn't to say that running is for everyone or that everyone should run. The medical research in support of exercise assumes that a joint has not been injured in some way and is functioning normally. In cases where ligaments have been torn or the cartilage in the joint has been damaged or removed, the results may be quite different. Certainly, pain that is present during or after a workout is a message that another less stressful activity should be substituted.

But here's another perspective: We don't just build muscle when we exercise; we also build ligament, tendon, and bone. We nourish cartilage as well, and exercise helps us rebuild or "remodel" damaged tissue. Dr. Bland states, "We know today beyond any doubt that all connective tissues remodel according to the lines of stress. This is important, not just in dealing with injuries and optimizing athletic performance; It also points the way to surviving to a healthy advanced age with intact and functional connective tissue."

Stiffness is another common problem of middle age. It can occur at rest or in motion from a variety of causes. It seems natural to let stiff joints take care of themselves, such as backing-off and resting. Actually, that response is counterproductive because it contributes to three common problems: tightness, delayed rate of healing due to diminished blood supply, and poor posture. The lesson is this: our musculoskeletal system responds to exercise in ways that heal, not harm, provided that we are sensible and listen to our bodies.

Some medical conditions can be predicted from the changes that gradually occur from aging and are aggravated by certain activities. For example, Dr. Douglas Tumen, a podiatrist writing about the aches and pains of running, states that, "Running has many benefits, but increased flexibility is not one of them. In fact, as running strengthens your leg muscles, it also shortens and tightens them." This is one reason that foot and leg problems, such as plantar fasciitis and Achilles tendinitis are so common in athletes who run regularly.

Plantar fasciitis, the commonly experienced heel pain which is most pronounced upon arising in the morning, results from this type of shortening of a band of fibers on the sole of your foot, coupled with thinning of the shock- absorbing fat deposits near the heel. During the day, the tightened band is stretched and ultimately loosens up, but not without some damage to the band. Then at night, the band shortens again and attempts to heal. Upon arising from bed, the shortened connective tissue is again stretched, tearing at the healing attempt that has occurred during the night and resulting in more pain. This condition can range from minor to disabling, especially when coupled with improper or aggressive training techniques.

Achilles' tendon ruptures, like the one sustained by former Vice President, Al Gore, are also due to similar tightening coupled with a diminished blood flow. Over time, the shortened tendon also has less elastic tissue in it, further inhibiting its flexibility. This problem starts as an inflammation of the tendon on the back of the foot, which does not heal readily due to the relatively poor blood supply in one portion of the tendon. If unprotected stress continues, the stage is set for an activity limiting injury, such as a ruptured tendon.

The American College of Sports Medicine (ACSM) recommends that regular flexibility training be part of a well-balanced exercise program, in order to minimize the changes that occur with aging. To minimize the impact of these cumulative postural changes and adaptive shortening, a regular flexibility program is recommended as part of the exercise programs prescribed. The reader may be familiar with a flexibility assessment examining the back, thigh, and legs, since flexibility is evaluated during the health and fitness assessments for the students passing through the U.S. Army War College. This assessment is a prelude for guidance on the need for stretching. What is known about stretching will be covered later in this section, as a component of a complete exercise program.

Prolonged postures contribute to other problems that often effect areas like the back, neck, and shoulders. Protracted sitting to write or type at a work station can result in a stance where the upper back is rounded, and the head and neck are positioned forward. This causes both connective tissue changes and makes muscles work overtime to support the head and neck against gravity. Gradually, the connective tissue in regions like the front of the chest and upper neck undergo permanent shortening, while in other areas the connective tissue is stretched out, resulting in permanent "habits". Also, the stretched muscles tend to weaken, much like a stretched rubber band is not as resilient as one of normal length. This contributes to the background noise of aches and pains. Fortunately, these connective tissue and muscular problems can be minimized by being aware of your posture and taking a few minutes throughout the day to stretch the kinks out.

In sum, while most anyone who enjoys an active lifestyle feels minor stiffness and muscle aches now and then, the evidence suggests that this shouldn't limit a personal exercise program. Even individuals with documented arthritis can (and should) exercise, advises Dr. Gordon Matheson and colleagues at the University of British Columbia, who found that activity-related pain is usually not the underlying source of discomfort. The real barrier for most individuals interested in participation in a regular exercise program is not minor aches and pains, but rather injury. Dr. Matheson's work with adults in their mid-fifties has shown that illness and injury are the number one and two causes of inability to participate in an exercise program. Those barriers must be avoided to maintain a regular exercise program and reap its benefits. In addition, the fact is that injuries are largely caused by training errors.

Source: Halle, J. (Ph.D., Lieutenant Colonel, US Army). Exercise Injury Prevention: Running in the Fast Lane. From "Executive Wellness: A Guide for Senior Leaders." U.S. Army Physical Fitness Research Institute (USAPFRI), U.S. Army War College (Eds.). Carlisle Barracks, Pennsylvania.

Running in the Fast Lane | Listening to your Body | Training Errors Training Principles | Practical Training | Psychological Factors