What Came First, the Meniscus Injury or Osteoarthritis?

I am working on this month’s Injury of the Month. It is on meniscus injuries.

I started my research for the injury workout and have started to come across some interesting findings. Let me share with you what I have found.

Does Toe Out or Toe In Put More Stress on the Knee When Walking?

 

What they Looked At:

Those with knee osteoarthritis tend to externally rotate their feet during gait, in order to unload the medial aspect of the knee by decreasing the adduction moment at the knee during late stance walking.

They got 11 healthy subjects to walk with their foot internal rotated and externally rotated to see how this affected the knee.

What They Found Out:

Internal rotation of the foot increased knee adduction moment and lateral-medial shear force magnitude during late stance phase of walking while external rotation decrease both.

What Does this Mean:

The foot position is a compensation strategy in order to unload the medial and lateral compartments of the knee.

Rick’s Comments:

We might have to rethink toeing out when it comes to clients with knee osteoarthritis. The common thinking has been to work to move them back to ideal foot position but this may not be the best solution. The toeing out maybe a modification in order to decrease pain, knee stress and prevent the progression of the injury.

Forcing a correction in the foot position may not be the best thing, but I still would work on recovery strategies for this patient in order to manage muscle tension and length.

You can get more information here: Lynn SK, Kajaks T, Costigan PA. (2008). The effect of internal and external foot rotation on the adduction moment and lateral-medial shear force at the knee during gait. J Sci Med Sport. 2008 Sep;11(5):444-51. Epub 2007 Sep 4.

 

Can Walking Lead to a Meniscus Injury?

I know you are thinking, if you are researching meniscus injuries, why are you talking about osteoarthritis? Give me a minute, keep reading.

What they Looked At:

They looked at 30 non-osteoarthritic women and looked at the forces in their knee during stance phase of walking.

They looked at the peak external knee adduction moment which is a combination of the ground reaction forces passing through the medial aspect of the centre of the knee joint.

The big deal about peak external knee adduction moment is that it’s responsible for 70% of the total knee joint load passing through the medial tibiofemoral compartment during walking.

Interesting Stuff from the Introduction:

  • Meniscal injury is a risk factor for the development and progression of knee osteoarthris
  • Meniscal injuries may be present with or without a history of significant trauma
  • Risk factor for meniscal injuries have been severe cartilage defects, diminished tibial cartilage volume and increased tibial bone area

What They Found Out:

“The presence of medial meniscal tears was also positively associated with the degree of internal foot rotation when the external knee adduction moment peaked during late stance, independent of the magnitude of the adductor moment.”

To sum it up, one’s walking gait can have an effect on their risk of meniscal injury.

Rick’s Comments:

Very interesting. Those with more of an internally rotated foot during walking put greater force (peak external knee adduction moment) on the medial side of the knee and this led to an increased risk of meniscal damage.

You can get more information here: Davies-Tuck ML, Wluka AE, Teichtahl AJ, Martel-Pelletier J, Pelletier JP, Jones G, Ding C, Davis SR, Cicuttini FM. (2008). Association between meniscal tears and the peak external knee adduction moment and foot rotation during level walking in postmenopausal women without knee osteoarthritis: a cross-sectional study. Arthritis Res Ther. 2008;10(3):R58. Epub 2008 May 20.

 

Can Foot Position Affect Hamstring Activation?

 

What they Looked At:

The researchers ask, if they changed the natural foot position during gait how would this affect knee adduction moment (KAM), lateral-medial shear forces and the medial-lateral hamstring muscle activation ratio in those with signs of knee osteoarthritis compared to a control group.

What They Found Out:

  • Those with knee osteoarthritis have an increased late stance knee adduction moment compared to a healthy group
  • Those with knee osteoarthritis have a decreased medial-lateral hamstring activation compared to a healthy group
  • External foot rotation decreased the knee adduction moment, lateral-medial shear force and hamstring activation ratio.
  • Internal foot rotation did not increase the knee adduction moment, lateral-medial shear force and hamstring activation ratio

Rick’s Comments:

This just confirms the articles from above.

The two interesting points is the research involved injured subjects (people diagnosed with knee osteoarthris) and you can see how results can change with healthy and injured subject. This can be seen with the internal rotation of the foot not affecting things compared to the papers above.

The second point is the hamstring and how the foot position decreased the hamstring ratio. Remember, they looked at foot position, not hip rotation. I can’t find the article but it showed that hip position did not have an affect on KAM.

You can get more information here: Lynn SK, Costigan PA. (2008). Effect of foot rotation on knee kinetics and hamstring activation in older adults with and without signs of knee osteoarthritis. Clin Biomech (Bristol, Avon). 2008 Jul;23(6):779-86. Epub 2008 Mar 14.

 

A Few Other Comments on Foot Position, Meniscus Injuries and Osteoarthritis:

– The peak external knee adduction moment during stance walking is similar in both dominant and nondominant limbs.

You can get more details here – Teichtahl AJ, Wluka AE, Morris ME, Davis SR, Cicuttini FM. (2009). The associations between the dominant and nondominant peak external knee adductor moments during gait in healthy subjects: evidence for symmetry. Arch Phys Med Rehabil. 2009 Feb;90(2):320-4.

– Hip muscle strengthening reduces knee symptoms in people with medial tibiofemoral osteoarthritis but does not affect knee adduction moment. Therefore focusing on hip strengthening will not influence the progression of osteoarthritis.

You can get more information here – Bennell KL, Hunt MA, Wrigley TV, Hunter DJ, McManus FJ, Hodges PW, Li L, Hinman RS. (2010). Hip strengthening reduces symptoms but not knee load in people with medial knee osteoarthritis and varus malalignment: a randomised controlled trial. Osteoarthritis Cartilage. 2010 May;18(5):621-8. Epub 2010 Feb 6.

 

– They are investigating how traditional quadriceps strengthening or neuromuscular exercises have an effect on peak external knee adduction moment. Neuromuscular exercises has been shown to be effective in ACL injury recovery and that is what I go through in Knee Injury Solution.

You can get more details here – Bennell KL, Egerton T, Wrigley TV, Hodges PW, Hunt M, Roos EM, Kyriakides M, Metcalf B, Forbes A, Ageberg E, Hinman RS. (2011). Comparison of neuromuscular and quadriceps strengthening exercise in the treatment of varus malaligned knees with medial knee osteoarthritis: a randomised controlled trial protocol. BMC Musculoskelet Disord. 2011 Dec 5;12:276.

I hope you enjoyed that research review.

I hope it to you thinking about foot position and meniscus injuries.

Rick Kaselj, MS