Running Knee Injuries 101

By Ian McMahan

Many runners will experience a knee injury at some point. Here’s an introduction to the most common sources of the pain.

Knee injuries with running may seem like death and taxes—inevitable. Many runners have stopped running because of knee pain or the worry that the constant impact will lead to a knee replacement or other problems down the road.

But don’t join your local aqua-aerobics class just yet. Despite the fact that studies show 30 to 50 percent of runners will suffer from an injury in a training year, they are neither inevitable nor untreatable when they do occur. Of the running injuries that do occur, one out of four involves the knee, making it the most commonly injured joint among runners.

The likelihood of an overuse injury occurring is influenced by outside factors such as training issues and running surface, as well as internal anatomic factors that are specific to each runner. Research on the risk factors for injury among runners shows that more experienced runners are at less risk for developing problems. Why? Because they were more likely to listen to their bodies and were less likely to make the training mistakes that contribute to many overuse injuries. Additionally, these more seasoned runners were conditioned to the impact and stress of running.

Research indicates another factor strongly associated with injury risk; a history of previous injury. As a prior running injury can lead to continued risk of future problems, research in Current Sports Medicine Reports stated, “The recovery and rehabilitation of these injuries clearly play a role in the subsequent risk of new running injuries.” Therefore, taking the time to fully rehabilitate from a knee injury and avoiding common training mistakes are crucial in avoiding the repeated cycle of injury.

Kneecap/Patellofemoral Pain/Runner’s Knee

So called Runner’s Knee or kneecap pain is the scourge of many runners. The patellofemoral, or kneecap joint, is formed by the patella/kneecap and the underlying groove of the femur. The kneecap plays a critical role in lengthening the lever arm of the quads, but in doing so is subjected to impact of up to eight times your bodyweight when running. Of the running injuries to the knee, kneecap pain is the most common, constituting a quarter of all knee injuries among runners.

Weak quads and outer hip muscles have both been linked to the development of kneecap pain. An increase in the angle of the hip and knee, known as the “Q-angle,” through excessive pronation or “knock-kneed” gait is also a risk factor.

Symptoms
Those with kneecap pain will usually experience a gradual onset of pain around the edge or underneath the kneecap during or after running. Other than running, this soreness can be aggravated by squatting, descending stairs or hills and sitting for long periods. Occasionally, mild swelling around the kneecap might be present but not the large amount of swelling present after a more traumatic knee injury. Frequently, there is an increase in the popping and cracking of the kneecap when bending and straightening the knee.

Treatment
Many researchers have found that those who suffer from kneecap pain have decreased quad and outer hip strength. As complete isolation of any one portion of the muscle has proven to be difficult to attain, the emphasis of quad strengthening exercises should be regaining overall quad muscle strength rather than complete isolation of any one portion of the muscle.

Research in Medicine and Science in Sports and Exercise found that female runners with kneecap pain had significantly less outer hip/hip abductor muscle strength in their injured leg. Other studies have shown the importance of hip strengthening as a significant piece of recovery from kneecap pain. The addition of orthotics to address alignment of the foot and leg can also be helpful in treating kneecap pain.

 

Iliotibial Band Inflammation

The Iliotibial Band is a thick band of connective tissue that runs from the outer hip to an attachment just below the knee. According to the most recent running injury surveys, IT Band injuries may have overtaken kneecap pain as the most common injury among runners. Like other overuse running injuries that generally result from the constant repetition of the running motion, Iliotibial Band Syndrome (ITBS) is hypothesized to result from the friction of the IT Band sliding over the end of the femur near the knee. It is the most common cause of lateral knee pain among runners.

Weak outer hip muscles and decreased strength of the quad and hamstrings are risk factors for the development of ITBS. Other factors, such as “bow legs” and excessive running on banked surfaces have been postulated to increase the risk of ITBS.

Symptoms
ITBS pain will usually come on after a specific distance or time spent running and consists of pain on the outside portion of the knee. Initially, these symptoms will subside after finishing the run, but frequently will return with subsequent training. This pain can progress to the point where it is present with daily walking and stairs. Inflammation and mild swelling can also be present in the area. It is distinguished from other types of lateral knee pain as the pain is usually slightly above the knee joint.

Treatment
Dr. Michael Fredericson, an expert in running-related injuries at Stanford, found that runners with ITBS were more likely to have weakness in the outer hip muscle and recommends strengthening of this area to treat the condition. Those with ITBS can also benefit from general quad and leg strengthening exercise. A comprehensive hip and IT Band stretching program has also been successful in improving ITB flexibility. Additionally, many sports medicine professionals use self-massage with a foam roll to address the soft-tissue mobility of the ITB.

 

Iliotibial Band Inflammation

The Iliotibial Band is a thick band of connective tissue that runs from the outer hip to an attachment just below the knee. According to the most recent running injury surveys, IT Band injuries may have overtaken kneecap pain as the most common injury among runners. Like other overuse running injuries that generally result from the constant repetition of the running motion, Iliotibial Band Syndrome (ITBS) is hypothesized to result from the friction of the IT Band sliding over the end of the femur near the knee. It is the most common cause of lateral knee pain among runners.

Weak outer hip muscles and decreased strength of the quad and hamstrings are risk factors for the development of ITBS. Other factors, such as “bow legs” and excessive running on banked surfaces have been postulated to increase the risk of ITBS.

Symptoms
ITBS pain will usually come on after a specific distance or time spent running and consists of pain on the outside portion of the knee. Initially, these symptoms will subside after finishing the run, but frequently will return with subsequent training. This pain can progress to the point where it is present with daily walking and stairs. Inflammation and mild swelling can also be present in the area. It is distinguished from other types of lateral knee pain as the pain is usually slightly above the knee joint.

Treatment
Dr. Michael Fredericson, an expert in running-related injuries at Stanford, found that runners with ITBS were more likely to have weakness in the outer hip muscle and recommends strengthening of this area to treat the condition. Those with ITBS can also benefit from general quad and leg strengthening exercise. A comprehensive hip and IT Band stretching program has also been successful in improving ITB flexibility. Additionally, many sports medicine professionals use self-massage with a foam roll to address the soft-tissue mobility of the ITB.

 

Patellar Tendinopathy

While pain at the front of the knee is most likely to be caused by kneecap pain, overuse conditions of the patellar tendon, the tendon that connects the kneecap to the lower leg bone, are also a frequent source of injury among runners. While there is an ongoing debate over the correct term to refer to patellar tendon conditions (tendinitis vs. tendinosis vs. tendinopathy), experts do agree that it is caused by repetitive strain to the tendon. Additionally, German researchers reported in the Journal of Biomechanics that “Forefoot running appears to be a major factor in the development of patellar tendinopathy.” In other words, a barefoot/minimalist style of running may be a risk factor for developing patellar tendon pain.

Symptoms
As both patellar tendinopathy and kneecap pain cause pain in the front of the knee, identifying the source of pain can be difficult. Patellar tendinopathy can be differentiated from kneecap pain as the pain is directly on the tendon or its connection to the bone, while kneecap pain is usually located around or underneath the kneecap. Patellar tendon pain is usually insidious and often is related to an abrupt change in training. As the condition progresses, pain will be present while running and often with daily activity. It is important to note that mild tenderness of the tendon is normal in many runners.

Treatment
A Sports Medicine article reviewing treatment of patellar tendon injuries recommends a focus on strengthening exercise, particularly of the quads. The article highlights the need for relative rest from running but stresses that complete rest may actually make the problem worse. Therefore, a careful balance between strengthening exercises and safe cardiovascular training should be the goal of a conservative recovery program.

If one wanted to establish a theme that runs through virtually every sports medicine article on knee injuries, it would be this: train smart. Overtraining is a major risk factor for injury and can be summarized as too many miles, too much intensity and too soon. Many running injuries suffered by both rookie and seasoned runners can be avoided by embracing the principles of cross-training, leg strengthening and a well-planned training program. Increases in volume and intensity should always be gradual and should never exceed more than 10 percent over the previous week or month.
Read more at http://running.competitor.com/2014/08/injury-prevention/running-knee-injuries-101_110938/5#4IyhH2hUbGuyvoVp.99

 

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s