External tibial torsion or femoral retrotorsion?

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This young lad presents to your office complaining of bilateral knee discomfort at the medial aspect, just below the patella, particularly when ascending and descending stairs and hills. You narrow it down to abnormal patellar tracking and 2 possibilities of who is driving the bus, but which is it?

Torsions of an extremity are said to exist when they measure two or more standard deviation‘s outside of normal. In external tibial torsion, the shaft of the tibia over rotates more than it’s 1.5° per year from zero at birth to greater than 19°. You are left with a foot that is has an increased progression angle and a center of gravity falls medial to the foot causing abnormal patellar tracking.

Femoral retro torsion is said to exist when the head of the femur over reduces from its 35° angle at birth to less than 8° resulting in severely limited internal rotation of the hips bilaterally. The lower extremity is often externally rotated to compensate.

An easy differential for the 2 is to drop a plumbline from the tibial tuberosity through the foot. This line normally passes through the second or between the second and third metatarsal‘s. If it falls medial to that it is eternal tibial torsion and lateral to that most likely internal tibial torsion or potentially a metatarsus varus or forefoot adductus.

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Another differential would be to perform “Craigs test” and measure how much internal and external rotation of the femur there is at the femoral acetabular articulation.

An easier way to put it is; those with femoral retrotorsion have less hip internal rotation and often increased amounts of external rotation; often they can’t even get past zero, never mind the requisite 4-6 degrees for normal gait. Those with increased internal rotation and diminished external rotation most likely have femoral antetorsion.

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So, Which is it? When his knees are Straightahead, his feet point out; when his feet are straightahead, his knees point inward. A plumbline from the tibial tuberosity passes medial to the second metatarsal. Looking at the pictures, you can see that he is external tibial torsion along with a sandal thong deformity that we talked about last week.

Dr Ivo Waerlop, one of The Gait Guys.

#externaltibialtorsion #outturnedfoot #increasedprogressionangle #kneepain #thegaitguys

We’ve told you once and we will tell you again…

Folks with femoral retro torsion often experience lower back pain with twisting movements

This left handed hydrology engineer Presented to the office with an acute onset of lower back pain following “swinging a softball bat”. He comments that he always “hit it out of the park“ and hit “five home runs“ in the last game prior to his backs demise.

note the internal tibial torsion. drop a plumbline from the tibial tuberosity. it should pass through the 2nd met or between the 2nd and 3rd met shafts

note the internal tibial torsion. drop a plumbline from the tibial tuberosity. it should pass through the 2nd met or between the 2nd and 3rd met shafts

note the internal tibial torsion. drop a plumbline from the tibial tuberosity. it should pass through the 2nd met or between the 2nd and 3rd met shafts

note the internal tibial torsion. drop a plumbline from the tibial tuberosity. it should pass through the 2nd met or between the 2nd and 3rd met shafts

He presented antalgic with a pelvic shift to the left side, flexion of the lumbar spine with 0° extension and a complete loss of the lumbar lordosis. He could not extend his lumbar spine past 0° and was able to flex approximately 70. Lateral bending was approximately 20° on each side. Neurological exam negative. Physical exam revealed bilateral femoral retro torsion as seen above. Note above the loss of internal rotation at the hips of both legs, thus he has very limited internal rotation of the hips. Femoral retroversion means that the angle of the neck of the femur (also known as the femoral neck angle) is less than 8°, severely limiting internal rotation of the hip and often leading to CAM lesions.

Stand like you’re in a batters box and swing like you’re left handed. What do you notice? As you come through your swing your left hip externally rotates and your right hip must internally rotate. He has no internal rotation of the right hip and on a good day, the lumbar spine has about 5° of rotation with half of that occurring at the lumbosacral junction. Guess what? The facet joints are going to become compressed!

bisect the calcaneus. the line should fall though the 2nd metatarsal or between the 2nd and 3rd met shafts

bisect the calcaneus. the line should fall though the 2nd metatarsal or between the 2nd and 3rd met shafts

bisect the calcaneus. the line should fall though the 2nd metatarsal or between the 2nd and 3rd met shafts

bisect the calcaneus. the line should fall though the 2nd metatarsal or between the 2nd and 3rd met shafts

Now combine that with bilateral 4 foot adductus (see photos above). His foot is already in supination so it is a poor shock observer.

Go back to your “batters box“. Come through your swing left handed. What do you notice? The left foot goes into a greater amount of pronation in the right foot goes into a greater amount of supination. Do you think this is going to help the amount of internal rotation available to the hip?

When folks present with lower back pain due to twisting injuries, make sure to check for femoral torsions. They’re often present with internal tibial torsion, which is also present in this individual.

Remember a while ago we said “things occur in threes”. That goes for congenital abnormalities as well: in this patient: femoral retro torsion, internal tibial torsion and forefoot adductus.

What do we do? Treat locally to reduce inflammation and take steps to try to improve internal rotation of the hips bilaterally as well as having him externally rotate his right foot when he is in the batteries box to allow him to "create" more internal rotation of the right hip.

Dr Ivo Waerlop, one of The Gait Guys

#internalrotation #hipproblem #femoraltorsion #femoralversion #retroversion #retrotorsion #thegaitguys

Right-sided knee pain in a cyclist...due to his hip?

This 54-year-old pilot presented to our office with pain on the outside of his right knee while cycling with his wife who is currently training for the triple bypass. The discomfort comes on later in the ride and is largely lateral. He thought it may be due to a seat position so he raised his seat up but then shortly developed lower back discomfort. Lowered the seat back down and presents to the office today. He is currently on a 54 cm Pierello road bike with a straight top tube.

Physical exam revealed him to have moderately limited internal rotation of the right hip which was approximately 5 degrees external rotation; left side had approximately 5 degrees of internal rotation. There was no significant leg length discrepancy or internal tibial torsion. Musculature, save for the long extensors the toes tests 5/5 and strong. Hip extension is 0 degrees bilaterally 5 flexion approximately 120 degrees with tightness mostly in the iliopsoas and some in the rectus femoris. Knee stability tests are unremarkable. Some patellofemoral discomfort with compression on the right. Palpable tightness in the right IT band.

X-rays revealed degenerative changes at the inferior aspect of the right acetabulum with a small spur an osteophyte formation.

His seat height was set so that at bottom dead center with the seat tube he had a 30 degree bend in his knee. Seat fore and aft position placed the knee over pedal spindle behind central axis of the pedal. His pedal stroke, seen on the video, reveals moderate internal rotation and medial displacement of the knee on the right side.

So what is going on?

It’s all about how folks compensate. This gent has very limited internal rotation of the right hip. Due to the nature of cycling, he is REALLY TRYING to get his 1st MTP down to the pedal to generate power. This is not unusual among cyclists, which is why what you think should be happening in gait does not always transfer over to cycling. in doing so, he MUST rotate SOMETHING forward (in this case his pelvis) medially to create the internal rotation needed. From this scenario, you can see how the posturing would increase knee valve and offer a mechanical advantage to the vastus lateralis, causing patello femoral dysfunction and knee pain.

So we did we do?

  • Moved his seat forward so that a line drawn from between the patella and tibial tuberosity fell through the center axis of the pedal

  • Angled his cleat so that he is able to have a greater progression angle moving forward, bringing his knee more into the sagittal plane

  • Began working on the hip to increase internal rotation working on the gluteus minimus, vastus lateralis and biceps femoris as well as hip capsule and ilio/ischio/pubofemoral ligaments

Dr Ivo Waerlop, one of The Gait Guys

#kneepain #cycling #hipproblem #femoralretrotorsion #thegaitguys #torsion

Low Back Pain? Check for Femoral Retrotorsion on the Same Side

note the right sided leg length discrepancy

note the right sided leg length discrepancy

right tibia is anatomically shorter

right tibia is anatomically shorter

more internal rotation available on the left side at the hip. Note the internal tibial torsion as well

more internal rotation available on the left side at the hip. Note the internal tibial torsion as well

very little internal rotation available at the right hip

very little internal rotation available at the right hip

This right handed concrete worker presented to our office with right-sided lower back pain. He was lifting a bag of concrete moving from left to right which she estimates weighing between 60 and 80 pounds. He did this repetitively throughout the day and subsequently developed right sided lower back pain. The pain is in the suprailiac region and is described as dull, achey. Is exacerbated by right rotation and right lateral bending.

His exam found him to have a right sided anatomical leg length discrepancy, tibial left (see above) and femoral retro torsion on the right with no internal rotation of the hip past 0 degrees (see picture of full internal rotation of the right hip and cmpare it with the left); left side had approximately 10 degrees internal rotation. He also has bilateral internal tibial torsion, R > L. Palpation findings revealed tightness in the lumbar multifidus and quadratus lumborum with a loss of lateral bending to the right at L2 through L4 and a loss of flexion about the right sacroiliac joint. Lower extremity reflexes were 2+ with bilateral symmetry; sensation to vibration was intact at the distal phalanges; motor strength was strong and graded as 5/5.

Think about the implications of his right-sided leg length discrepancy first. This places his foot and a relative supinated posture compared to the left. Remember that supination is plantar flexion, inversion and adduction.

His femoral retro torsion on the right limits his internal rotation at the hip. When his foot planted with a diminished progression angle secondary to the internal tibial torsion, and he has to rotate from left to right, very little, if any motion, can occur at the right hip and therefore must occur in the lumbar spine. Remember the lumbar spine has very limited range of motion begin with with most of that occurring at the L5-S1 junction, depending upon its anatomy. Now superimpose a long lever load and rotary force. Back pain!

We instructed him on proper lifting technique and also talked about keeping the shoulders and hips in the same plane when lifting or load. If he does need to lift a load and spin unilateral on his right lower extremity, we asked him to externally rotate the right lower extremity. He was treated with manipulation and neuromuscular acupuncture.

If you have somebody with unilateral lower back pain, think about the implications if they have any femoral torsion or version present

Dr. Ivo Waerlop, one of The Gait Guys.

#lowbackpain #LBP #femoralretrotorsion #femoral #torsion #gait #gaitanalysis #thegaituys

Do you know your Torsions? If so, then you here is what you need to know about twisted people...

Are you twisted? Are your patients/clients twisted? You know about tibial torsions from yesterday but do you know about femoral torsions?

To go along with yesterdays post, here is some more info on femoral torsions. If you missed it, click here

The degree of version is the angle between an imaginary line drawn through the condyles of the femur and an imaginary line drawn through the head and neck of the femur. This is often referred to as the femoral neck angle or FNA.

IMAGE SOURCE: Michael T Cibulka; Determination and Significance of Femoral Neck Anteversion,  Physical Therapy , Volume 84, Issue 6, 1 June 2004, Pages 550–558,  https://doi.org/10.1093/ptj/84.6.550

IMAGE SOURCE: Michael T Cibulka; Determination and Significance of Femoral Neck Anteversion, Physical Therapy, Volume 84, Issue 6, 1 June 2004, Pages 550–558, https://doi.org/10.1093/ptj/84.6.550

Beginning about the 3rd month of embryological development (Lanz and Mayet 1953) the femoral neck angle reaches 60 degrees and decreases, with growth, to about 40 degrees (with an average of 30-60 degrees) at birth. It then decreases 25-30 degrees by adulthood to 8-20 degrees with males being at the lower and females at the upper end of the range.

The FNA angle, therefore, diminishes about 1.5 degrees a year until about 15 years of age. Femoral neck anteversion angle is typically symmetrical from the left side to the right side.

What causes torsion in the first place? By the sixth month in utero, the lumbar spine and hips of the fetus are fully flexed, so perhaps it is positional. Other sources say it coincides with the degree of osteogenesis. There is a growing consensus that muscular forces are responsible, particularly the iliopsoas or possibly the medial and lateral hip rotators.

Additional changes can occur after birth, particularly with sitting postures. “W” sitting or “cross legged” sitting have been associated with altering the available range of motion and thus the FNA, with the range increased in the direction the hip was held in; W sitting causing increased internal rotation and antetorsion and cross legged causing external rotation and retro torsion.

image source: T Michaud, with permission

image source: T Michaud, with permission

As discussed previously, there are at least 3 reasons we need to understand torsions and versions, They can alter the progression angle of gait, they usually affect the available ranges of motion of the limb and they can alter the coronal plane orientation of the limb.

  1. fermoral torsions often alter the progression angle of gait. In femoral antetorsion torsion, the knees often face inward, resulting in an intoed gait and a decreased progression angle of the foot. This can be differentiated from internal tibial torsion (ITT) by looking at the tibia and studying the position of the tibial tuberosity with respect to the foot, particularly the 2nd metatarsal. In ITT, the foot points inward while the tibial tuberosity points straight ahead. In an individual with no torsion, the tibial tuberosity lines up with the 2nd metatarsal. If the tibial tuerosity and 2nd met are lined up, and the knees still point inward, the individual probably has femoral ante torsion. Remember that a decreased progression angle is often associated with a decreased step width whereas an increased angle is often associated with an increased step width.

  2. Femoral torsions affect available ranges of motion of the limb. We remember that the thigh leg needs to internally rotate the requisite 4-6 degrees from initial contact to midstance (most folks have 40 degrees) If it is already fully internally rotated (as it may be with femoral retro torsion), that range of motion must be created or compensated for elsewhere. This, much like internal tibial torsion, can result in external rotation of the affected lower limb to create the range of motion needed.

  • Femoral retro torsion results in less internal rotation of the limb, and increased external rotation.

  • Femoral ante torsion results in less external rotation of the limb, and increased internal rotation.

          3. femoral torsions usually do not effect the coronal plane orientation of the lower limb,      since the “spin” is in the transverse or horizontal plane.

The take home message here about femoral torsions is that no matter what the cause:

  • FNA values that exist one to two standard deviations outside the range are considered “torsions”

  • Decreased values (ie, less than 8 degrees) are called “retro torsion” and increased values (greater than 20 degrees) are called “ante torsion”

  • Retro torsion causes a limitation of available internal rotation of the hip and an increase in external rotation

  • Ante torsion causes an increase in available internal rotation of the hip and decrease in external rotation

  • Femoral ante torsion will be perpetuated by “W” sitting (sitting on knees with the feet outside the thighs, promoting internal rotation of the femur)

  • Femoral antetorsion will be perpetuated by sitting cross legged, which forces the thigh into external rotation.

Michael T Cibulka; Determination and Significance of Femoral Neck Anteversion, Physical Therapy, Volume 84, Issue 6, 1 June 2004, Pages 550–558, https://doi.org/10.1093/ptj/84.6.550

http://www.clinicalgaitanalysis.com/faq/torsion.html

Souza AD, Ankolekar VH, Padmashali S, Das A, Souza A, Hosapatna M. Femoral Neck Anteversion and Neck Shaft Angles: Determination and their Clinical Implications in Fetuses of Different Gestational Ages. Malays Orthop J. 2015;9(2):33-36.

image from: http://boneandspine.com/what-is-anteversion-and-retroversion/

image from: http://boneandspine.com/what-is-anteversion-and-retroversion/

Femoral versions and torsions?

While searching for something else, we ran across this post. A pretty good lay discussion and explanation about femoral torsions. Technically, versions are NORMAL variations or limb rotations that are within accepted limits and TORSIONS are pathological, when it measures 2 or greater standard deviations from the mean and is considered pathological. Femoral versions are the angular difference between the transcondylar and transcervical axes. The femur is normally anteverted (1). 

We liked the last section talking about how to compensate for them and "acceptable" work arounds and biomechanics. 

https://b-reddy.org/2013/05/09/talking-about-hip-retroversion/

1. Staehli L in: Fundamentals of Pediatric Orthopedics Lippincott Williams & Wilkins, Jun 15, 2015 p 144

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 Every foot has a story. 

 This is not your typical “in this person has internal tibial torsion, yada yada yada” post.  This post poses a question and the question is “Why does this gentleman have a forefoot adductus?”

The first two pictures show me fully internally rotating the patients left leg. You will note that he does not go past zero degrees and he has femoral retroversion. He also has bilateral internal tibial torsion, which is visible in most of the pictures. The next two pictures show me fully internally rotating his right leg, with limited motion, as well and internal tibial torsion, which is worse on this ® side

 The large middle picture shows him rest. Note the bilateral external rotation of the legs. This is most likely to create some internal rotation, because thatis a position of comfort for him (ie he is creating some “relief” and internal rotation, by externally rotating the lower extremity)

 The next three pictures show his anatomically short left leg. Yes there is a large tibial and small femoral component. 

 The final picture (from above) shows his forefoot adductus. Note that how, if you were to bisect the calcaneus and draw a line coming forward, the toes fall medial to a line that would normally be between the second and third metatarsal’s. This is more evident on the right side.  Note the separation of the big toe from the others, right side greater than left. 

Metatarsus adductus deformity is a forefoot which is adducted in the transverse plane with the apex of the deformity at LisFranc’s (tarso-metatarsal) joint. The fifth metatarsal base will be prominent and the lateral border of the foot convex in shape . The medial foot border is concave with a deep vertical skin crease located at the first metatarso cuneiform joint level. The hallux (great toe) may be widely separated from the second digit and the lesser digits will usually be adducted at their bases. ln some cases the abductor hallucis tendon may be palpably taut just proximal to its insertion into the inferomedial aspect of the proximal phalanx (1)

Gait abnormalities seen with this deformity include a decreased progression angle, in toed gait, excessive supination of the feet with low gear push off from the lesser metatarsals. 

 It is interesting to note that along with forefoot adductus, hip dysplasia and internal tibial torsion are common (2) and this patient has some degree of both. 

 His forefoot adductus is developmental and due to the lack of range of motion and lack of internal rotation of the lower extremities, due to the femoral retrotorsion and internal tibial torsion.  If he didn’t adduct the foot he would have to change weight-bearing over his stance phase extremity to propel himself forward. Try internally rotating your foot and standing on one leg and then externally rotating. See what I mean? With the internal rotation it moves your center of gravity over your hip without nearly as much lateral displacement as would be necessary as with external rotation. Try it again with external rotation of the foot; do you see how you are more likely displace the hip further to that side OR lean to that side rather than shift your hip? So, his adductus is out of necessity.

Interesting case! When you have a person with internal torsion and limited hip internal rotation, with an adducted foot, think of forefoot adductus!


1.  Bleck E: Metatarsus adductus: classification and relationship to outcomes of treatment. J Pediatric Orthop 3:2-9,1983.

2. Jacobs J: Metatarsus varus and hip dysplasia. C/inO rth o p 16:203-212, 1960

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Subtle clues. Helping someone around their anatomy

This patient comes in with low back pain of years duration, helped temporarily with manipulation and activity. Her exam is relatively benign, save for increased lumbar discomfort with axial compression in extension and extension combined with lateral bending. Believe it or not, her abdominal and gluteal muscles (yes, all of them) test strong (no, we couldn’t believe it either; she is extremely regular with her exercises). She has bilateral internal tibial torsion (ITT) and bilateral femoral retro torsion (FRT). She has a decreased progression angle of the feet during walking and the knees do not progress past midlilne. There is a loss of active ankle rocker with gait, but not on the exam table; same with hip extension. 

We know she has a sweater on which obscures things a bit, but this is what you have to work with. Look carefully at her posture from the side. The gravitational line should pass from the earlobe, through the shoulder, greater trochanter and through or just anterior to the lateral malleolus.

In the top picture, can you see how her pelvis is anterior to this line? Do you see how it gets worse when she lifts her hands over her head (yes, they are directly over head)? This can signify many things, but often indicates a lack of flexibility in the lumbar lordosis; in this case, she cannot extend her lumbar spine further so she translates her pelvis forward. Most folks should have enough range of motion from a neutral pelvis and enough stability to allow the movement to occur without a significant change. Go ahead, we know you are curious, go watch yourself do this in a mirror and see if YOU change.

Looking at the bottom left picture, can you pick out that she has a genu valgus? Look at the hips and look at the tibial angle.

In the bottom left picture, did you note the progression angle (or lack of) in her feet? This is a common finding (but NOT pathognomonic) in patients with internal tibial torsion. Notice the forefoot adductus on the right foot?

So what do we think is going on?

  • ITT and FRT both limit the amount of internal rotation of the thigh and lower leg. Remember you NEED 4 degrees of each to walk normally. Most folks have significantly more
  • if you don’t have enough internal rotation of the lower extremity, you will need to “create” it. You can do this by extending the lumbar spine (bottom picture, right) or externally rotating the lower extremity
  • Since her ITT and FRT are bilateral, she flexes the pelvis and nutates the pelvis anteriorly.
  • the lumbar facet joints should only carry 20% of load
  • she is increasing the load and causing facet imbercation resulting in LBP.

What did we do?

  • taught her about neutral pelvic positioning, creating more ROM in the lumbar spine
  • had her consciously alter her progression angle of her foot on strike, to create more available ROM in internal rotation
  • encouraged her to wear neutral shoes
  • worked on helping her to create more ankle rocker and hip extension with active drills and exercise (ie gait rehabilitation); shuffle walks, Texas walk, toes up walking, etc

why didn’t we put her in an orthotic to externally rotate her lower extremity? Because with internal tibial torsion, this would move her knee outside the saggital plane and create a biomechanical conflict at the knee and possibly compromising her meniscus.

Cool case, eh? We thought so. Keep on learning so your brain keeps expanding. If you are not growing your brain, you are shrinking it!

The Gait Guys

The Power of Observation: Part 2

Let’s take a closer look at yesterdays post and the findings. If you are just picking up here, the post will be more meaningful if you go back and read it. 


The following are some explanations for what you were seeing:

torso lean to left during stance phase on L?

if he has a L short leg, he will need to clear right leg on swing phase. We have spoken of strategies around a short leg in another post. This gentleman employs 2 of the 5 strategies; torso lean is one of them

increased progression angle of both feet?

Remember he has femoral retroversion. You may have read about retrotorsion here. He has limited internal rotation o both thighs and must create the requisite 4-6 degrees necessary to walk. He does this by spinning his foot out (rotating externally).

decreased arm swing on L?

This is most likely cortical, as he seems to have decreased proprioception on both legs during 1 leg standing. Proprioception feeds to the cerebellum, which in turn fires axial extensors through connections with the vestibular system. Diminished input can lead to flexor dominance (and extensors not firing). Note the longer stride forward on the right leg compared to the left with less hip extension (yes, we know, a side view would be helpful here).

circumduction of right leg?

This is the 2nd strategy for getting around that L short leg.

clenched fist on L?(esp when standing on either leg)

see the decreased arm swing section. This is a subtle sign of flexor dominance, which appears to be greater on the right.

body lean to R during L leg standing?

This is again to compensate for the L short leg. He has very mild weakness of the left hip abductors as well, more when moving or using them in a synergistic fashion (ie functional weakness) than to manual testing.

Well, what do you think? Now you can see how important the subtle is and that gait analysis may complex than many think.

We are and we remain, the Geeky Guru’s of Gait: The Gait Guys

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What can we learn from a trip to the museum and ancient pachyderms?

Lessons from the Denver Museum of Science and the “Mammoths and Mastodons” exhibit.

Leave it to gait nerds to notice stuff like this. These are the things that keep us up at night.


Look carefully at the last 2 pictures, especially the femurs. Besides their grandious size, what do you see. Femoral anterversion! The angle of the femur head with the shaft of the femur is quite large. We remember from our discussion of anteversion previously (see here); that femoral anteversion allows a greater amount of internal rotation of the head of the femur in the acetabulum (ie the ball in the socket).

Now look at the top picture. Besides a cross over gait that Dr Allen was quick to point out. What do you see?  Ok…tremendous glutes : ). What else? Look at the second picture for a hint. You got it! Internal rotation of the legs.


Think about how pachyderms are put together compared to say, reptiles, specifically lizards. The legs are UNDER the body in the former and STICK OUT from the body in the latter. Watch them walk. The latter swing their tails and the former have the legs under their center of mass.

Extrapolate this to human gait (We know, it’s a stretch, but you have a great imagination). Some people have their weight under their body (ie, they have sufficient internal rotation of the hips to allow this; many of these folks have more anteverision than retroversion. also remember that we are speaking versions, NOT torsions here). Think about retroverted folks. Wider stance, wider gait, just like reptiles.

Ok, maybe this was a stretch, but it was cool, no?

The Gait Guys. Comparing pachyderms to humans….reallly.

all material copyright 2013 The Gait Guys/The Homunculus Group. All rights reserved.

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Twisted, Part 4

 

Hopefully you have been keeping us with us. If you missed the 1st 3 of this series, go back 3 weeks and start reading again, or do a search on the blog page for “torsion”.

The final chapter of developmental versions involves the femur. The degree of version is the angle between an imaginary line drawn through the condyles of the femur and an imaginary line drawn through the head and neck of the femur. This is often referred to as the femoral neck angle or FNA.

Beginning about the 3rd month of embryological development (Lanz and Mayet 1953) and reaches about 40 degrees (with an average of 30-60 degrees) at birth. It then decreases 25-30 degrees by adulthood to 8-20 degrees with males being at the lower and females at the upper end of the range.

The FNA angle, therefore, diminishes about 1.5 degrees a year until about 15 years of age. Femoral neck anteversion angle is typically symmetrical from the left side to the right side.

What causes torsion in the first place? By the sixth month in utero, the lumbar spine and hips of the fetus are fully flexed, so perhaps it is positional. Other sources say it coincides with the degree of osteogenesis. There is a growing consensus that muscular forces are responsible, particularly the iliopsoas  or possibly the medial and lateral hip rotators.

Additional changes can occur after birth, particularly with sitting postures. “W” sitting or “cross legged” sitting have been associated with altering the available range of motion and thus the FNA, with the range increased in the direction the hip was held in; W sitting causing increased internal rotation and antetorsion and cross legged causing external rotation and retro torsion.

As discussed previously, there are at least 3 reasons we need to understand torsions and versions, They can alter the progression angle of gait, they usually affect the available ranges of motion of the limb and they can alter the coronal plane orientation of the limb.

1. fermoral torsions often alter the progression angle of gait.  In femoral antetorsion torsion, the knees often face inward, resulting in an intoed gait and a decreased progression angle of the foot. This can be differentiated from internal tibial torsion (ITT) by looking at the tibia and studying the position of the tibial tuberosity with respect to the foot, particularly the 2nd metatarsal. In ITT, the foot points inward while the tibial tuberosity points straight ahead. In an individual with no torsion, the tibial tuberosity lines up with the 2nd metatarsal. If the tibial tuerosity and 2nd met are lined up,  and the knees still point inward, the individual probably has femoral ante torsion. Remember that a decreased progression angle is often associated with a decreased step width whereas an increased angle is often associated with an increased step width. See the person with external tibial torsion in the above picture?

2. Femoral torsions affect available ranges of motion of the limb. We remember that the thigh leg needs to internally rotate the requisite 4-6 degrees from initial contact to midstance (most folks have 40 degrees) If it is already fully internally rotated (as it may be with femoral retro torsion), that range of motion must be created or compensated for elsewhere. This, much like internal tibial torsion, can result in external rotation of the affected lower limb to create the range of motion needed.

Femoral retro torsion results in less internal rotation of the limb, and increased external rotation.

Femoral ante torsion results in less external rotation of the limb, and increased internal rotation.

3. femoral torsions usually do not effect the coronal plane orientation of the lower limb, since the “spin” is in the transverse or horizontal plane.

The take home message here about femoral torsions is that no matter what the cause:

  •  FNA values that exist one to two standard deviations outside the range are considered “torsions”

  • Decreased values (ie, less than 8 degrees) are called “retro torsion” and increased values (greater than 20 degrees) are called “ante torsion”
  • Retro torsion causes a limitation of available internal rotation of the hip and an increase in external rotation

  • Ante torsion causes an increase in available internal rotation  of the hip and decrease in external rotation
  • Femoral ante torsion will be perpetuated by “W” sitting (sitting on knees with the feet outside the thighs, promoting internal rotation of the femur)

  • Femoral antetorsion will be perpetuated by sitting cross legged, which forces the thigh into external rotation.

 

Stay tuned for a case tomorrow to test your learning over the last few weeks.

 

We remain: Bald, good looking and intelligent…The Gait Guys

 

 

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