Month: April 2014

“Knee bone con-nect-ed to the…”?

Can you sing “Dem Dry Bones“? If you don’t know the spiritual by name, I bet you can intone at least some of the lyrics:

…the foot bone’s connected to the leg bone, the leg bone’s connected to the knee bone, the knee bone’s connected to the thigh bone…

Josephine Baker dances the Charleston

Josephine Baker dances the Charleston

Beyond the direct structural connection between the “knee bone,” or patella, and the “thigh bone,” or femur, is another connection that will be of particular interest to athletes and other individuals afflicted with or susceptible to patellar femoral pain syndrome (PFPS), a disorder often referred to as “runner’s knee.” And this is the connection between the knee and the gluteus medius, the muscles situated above and toward the outer sides of the much larger gluteus maximus muscles.

The knee bone is 'connected' to the gluteus medius

The knee bone is ‘connected’ to the gluteus medius

If you read my Samba Your Way to Beautiful Glutes post or joined my Samba webinar in October, you’ll know how to locate these paired muscles, and you’ll appreciate at least some of what they do.

How to locate the gluteus medius

How to locate the gluteus medius

Gluteus medius muscles, pelvic anteversion, and knee health

According to modern conventional wisdom, it’s considered normal for young children to have inward-turning knees, which are expected to straighten out by about age 7. What I’ve observed in village Africa and other nonindustrial cultures is that because children are carried on their caregivers’ hips and backs, children’s legs are externally rotated from the very youngest ages.

This Burkina baby was patterned to externally rotate his legs as he was carried on his mother's back

This Burkina baby was patterned to externally rotate his legs as he was carried on his mother’s back

In contrast, in the US and other modern industrial cultures, the  internal rotation of the legs is often maintained into adulthood.

Internally rotated legs are common in modern industrial cultures, even in adulthood

Internally rotated legs are common in modern industrial cultures, even in adulthood

Because the gluteus medius muscles are external leg rotators, strengthening these muscles can counter internal leg rotation, helping  the kneecaps to align and track better. (To check the tracking of your patella, sit down, place your palm over one of your knees, and then flex your leg to feel and follow the triangular kneecap glide up and down along the end of your femur.)

Strong gluteus medius muscles are important because people whose “glute mēds” are underdeveloped are at increased risk of knee and other lower-limb injuries, including patellafemoral pain syndrome. Preventing PFPS, or managing its painful symptoms if the problem has already occurred, are just a couple of reasons why–when you stand, walk, and run–you want to use your glute meds and externally rotate your legs. 

In addition to promoting knee health, external leg rotation facilitates an anteverted pelvic position and a well-stacked spine

In addition to promoting knee health, external leg rotation facilitates an anteverted pelvic position and a well-stacked spine

Gluteal muscle activity and patellofemoral pain syndrome (PFPS)

If you’ve ever felt a dull, aching pain under or around your kneecap where it connects with the lower end of your femur, you may have experienced patellar femoral pain, especially if the pain occurred when you were sitting for a long stretch of time with your knees bent, or you were kneeling, squatting, or walking up or down stairs.

Votive_relief_Asklepios

Knee pain is nothing new; this Greek votive relief for the cure of an injured knee dates back to 100-200 AD

And, if you have been diagnosed with PFPS, you’re not alone. Gluteal Muscle Activity and Patellofemoral Pain Syndrome–A Systematic Review, which was published earlier this year in the British Journal of Sports Medicine, confirms the connection between the knee and the gluteus medius. By synthesizing electromyography (EMG) measurements of the gluteus medius muscles during a range of functional tasks as reported in 10 case-controlled studies, all of which evaluated EMG activity of the gluteus medius, the authors strove to elucidate the relationship between gluteal muscle activity and PFPS. Among their observations and conclusions:

  • Patellofemoral pain syndrome is one of the most common presentations to sports medicine practitioners; of 2500 presentations to sports medicine clinics 25% of all injuries were PFPS
  • Individuals with PFPS exhibit reduced gluteus medius and gluteus maximus muscle strength
  • Growing evidence supports the efficacy of gluteal muscle strengthening for PFPS and gluteal-muscle strengthening programs have been associated with positive clinical outcomes
In a nutshell, if you have good strength in your gluteus medius muscles, your knees will be in better shape.

In a nutshell, if you have good strength in your gluteus medius muscles, your knees will be in better shape.

Walking is connected to healthy knees

Think about it: Walking is something most of us do a lot, although according to the 2010 study Pedometer-Measured Physical Activity and Health Behaviors in US Adultsthe 5,117 steps Americans typically take each day are not enough–and in fact represent thousands fewer steps than those taken by our counterparts in Australia (9,695 steps), Switzerland (9,650 steps), and Japan (7,168 steps). But even if  we step just 5,000 times a day, if we engage our gluteus medius muscles with each step, that’s still a lot of repetitions to help “re-architecture” our legs and minimize the risk of PFPS. 

The pelvis serves as our postural foundation, and one of the keystones for healthy postures is to allow the pelvis to be anteverted. When your pelvis is anteverted and your “behind is out behind you,” then the whole pack of muscles that includes the hamstrings, the gluteus maximus, and the gluteus medias can work to advantage, strengthening themselves, inducing circulation in the appropriate places, and bearing stress.

Ancient coin features Apollo (with anteverted pelvis!)

Ancient coin from Caulonia features Apollo with anteverted (ie, tipped forward) pelvis

Beyond this, the relationship between external leg rotation, pelvic anteversion, and the action of the gluteus medius is cyclic. In order for the gluteus medius to be in a position of mechanical advantage, some degree of pelvic anteversion is required. And, if we are to believe the observations summarized in the British Journal of Sports Medicine review, strong gluteus medius action relates to a diminished risk of PFPS.

Eadweard Muybridge's 'human male walking' demonstrates strong gluteal action in the rear leg

Eadweard Muybridge’s ‘human male walking’ demonstrates strong gluteal action in the rear leg

 

Muybridge_Strong_Gluteus_Medius_Action

The interconnectedness between external leg rotation, pelvic anteversion, and strong gluteus medius action is beautifully illustrated in the detail of Muybridge’s “animal locomotion” photo and “film” above.

“Dem Dry Bones”

Bottom line, the knee bone is connected to the thigh bone, but it’s also connected to the gluteus medius, and this is a fairly direct connection because these paired muscles externally rotate the legs.

Finally–not just because the lyrics are right on point with this lesson, but because he plays and sings so artfully and with such a great sense of fun–I hope you’ll listen to Fats Waller’s wonderful take on “Dem Dry Bones.”

 

Image Credits:
Josephine Baker Dances the Charleston, Wikimedia Commons
The Bath, Charles Degas, Wikimedia Commons, Public Domain
How to Locate the Gluteus Medius, Esther Gokhale
Burkina Baby, Esther Gokhale
X-ray of “Knock Knee,” Biomed Central, Wikipedia
The Spinal Cord, Bruce Blaus, Wikimedia Commons
Greek Votive Relief Knee Injury, Marie-Lan Nguyen, Blacas Collection, Wikimedia Commons
Female Jogger, Mike Baird, Creative Commons
Human Male Walking (animation), Eadweard Muybridge, Wikimedia Commons
Animal Locomotion, Eadward Muybridge, Wikimedia Commons
Ancient Coin from Caulonia: Classical Numismatic Group, Inc, Wikimedia Commons

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