Weak muscles may cause “runner’s knee”

By Tom Nordlie • Published: March 23rd, 2010
Category: Health in a Heartbeat

If your exercise routine includes running, you may be acquainted with a painful condition called runner’s knee.

The symptoms include swelling, pain around the kneecap, and popping or clicking sensations.

It’s one of the most common chronic knee problems, affecting one in four physically active people.

But little research has been done to determine how it’s caused.

A study published in The American Journal of Sports Medicine attempted to root out the risk factors.

Scientists enrolled more than fifteen-hundred first-year students in the U-S Naval Academy.

About forty percent of them were women. None had a recent history of runner’s knee.

As students entered the study, researchers made a sophisticated assessment of their biomechanics.

After being outfitted with sensors, students jumped off a box to a platform loaded with more sensors, then jumped vertically as high as possible.

They also did isometric resistance exercises.

The data provided insights about muscle strength and bone alignment.

Researchers tracked the students for up to two-and-a-half years. The academy regimen included sports and daily physical training.

Altogether, forty participants developed runner’s knee.

Researchers checked their biomechanical assessments, and found some common factors.

One was, their knees collapsed inward when under stress.

Another was weak quadriceps muscles.

The result? The kneecap moved outward when it shouldn’t have.

This study isn’t the last word on runner’s knee, but it could hold important lessons for doctors and their patients.

So if your kneecaps ache after a run, rehab exercises could help.

By strengthening the right muscles, you might turn running into a “no pain, all gain” situation.