Opedix Knee Support System Reduces Knee Joint Loading during Running

Michael J. Decker, Ph.D.
Director of Research and Business Development

The external knee adduction moment is a biomechanical variable that predicts load distribution between the medial and lateral compartments of the knee when the foot is in contact with the ground during the stance phase of walking or running. This moment produces the outward motion of the knee (knee adduction) and larger moments are associated with increased medial knee compartment loading, pain and disease progression.

Mechanical interventions such as knee braces and foot orthotics have been developed to adjust knee joint alignment in order to reduce the external knee adduction moment and unload the medial knee compartment. Although these devises have successfully reduced the external knee adduction moment by as much as 38%, they are reportedly uncomfortable, bulky and have low patient compliance.

Opedix has made available a running compression garment with a patented Knee Support System designed to comfortably reduce knee joint loading by resisting the lateral motion of the knee during dynamic activities. Three-dimensional gait analysis was performed to quantify the effectiveness of the Opedix Knee Support System design. The lower extremity motions of a cohort of experienced runners performing multiple over-ground running trials with and without the Opedix Knee Support System were investigated in a controlled laboratory setting using high-speed cameras and force sensors. Knee adduction range of motion and the peak external knee adduction moment were statitstically compared between the two conditions.

The results of this study revealed that wearing the Opedix Knee Support System garment reduced the knee adduction range of motion by 21% and the peak external knee adduction moment by 16%. The greatest reductions in the peak external knee adduction moment were found for the heaviest runners and for the runners that demonstrated the greatest decline in knee adduction range of motion. These data are interpreted to indicate that the Opedix Knee Support System garment enhanced knee alignment and reduced the knee joint load generated during running that would presumably be sustained by the medial compartment.

Increased knee adduction and peak external knee adduction moments are related to knee joint loading and disease progression. Therefore it is likely that individuals with healthy knees and minor alignment issues could benefit from wearing the Opedix Knee Support System garment during running to avoid high joint loads and lower the rate of knee degeneration.

One of the benefits of being a writer about running is that occasionally I receive samples of running clothing to try. Early in the summer, I was asked to test a pair of Opedix® running tights. I selected the coolest tights they carry, recognizing that it would probably be too hot to test them in the summer in Texas.

With summer temperatures ranging from 85ºF to 105ºF and high humidity, I don't find running tights very comfortable. Even shorts get wet with sweat very quickly under those conditions! So I decided to wait before putting them to a real test.

Today was the first day of fall and, as if it knew, the temperature dropped to around 65ºF. So I finally got to test them. In a word, I was impressed.

When I put the running tights on, I was concerned that they might bunch behind the knee, but this worry proved to be unfounded. They are made of two different thicknesses of material: a light synthetic that stays cool but includes some spandex, and a heavier supportive material. You can read the details of these on their website – I'm just giving my non-technical impression as a runner.

They have an ITB support that runs from the side of the hip down the outside of the thigh to about half way down. At that point, the support forms a band around the leg just above and around the knee, leaving room for the patella (kneecap) and the back of the knee. The remaining areas are covered with the thinner material, except for a supportive band on the lower leg.

Clearly, some careful anatomical design work has gone into the making of the Opedix® running tights!

So how do they feel when you're running? I was surprised at how much support they gave to my ITB, hamstrings and calf muscles. Those areas generally hurt for me at the beginning of every run, but today they felt strong and pain-free.

As the run progressed, my legs started to feel comfortably warm and strong. I found I was running easily and enjoying it even more than usual. After the run, I unzipped the lower legs, rolled them up to the knee, stretched and did a weight workout.

I have worn running tights before, mostly for warmth, but had not previously experienced the support and comfort that the Opedix® tights give. Can I recommend them? Definitely yes! (And I don't get commission from them.)

They come in various weights, so I would suggest that you buy the type that is most appropriate for the climate and time of year where you are running. With my new Opedix® running tights, I'm really looking forward to my winter runs this year!

Running Tights by Opedix
Posted by Alan Jenkin on Wednesday, September 23, 2009 Under: running