All that is twisted is not tibial
Last week we posted on measuring tibial torsions (click here to read that post). This week we are posting on measuring the other, often over looked torsion: “femoral torsion”.
Perhaps you have read some of our posts on femoral torsion, particularly this one.
We remember that as hip (thigh) flexion increases, the amount of internal rotation of the femur decreases. This is due largely to the direction of the hip capsule ligaments (ishiofemoral, iliofemoral and pubeofemoral ligaments) “spiraling” from their attachment from the femur to the innominate. This may seem like a subtle detail until you thing about how much hip flexion occurs when we do a squat, and what exactly, is the position of our feet.
We start life with the hips anteverted (ie, the angle of the neck of the femur with the shaft of the femur is > 12 degrees; in fact at birth it is around 35 degrees) and this angle should decrease as we age to about 8-12 degrees). When we stand, the heads of our femurs point anteriorly; it is just a matter of how much (ante version or ante torsion) or how little (retro version or retro torsion) that is. If you are a precise person and would really like to geek out on the difference between versions or torsions, check out this post here.
Measurement is important, because the more retro torsion you have (ie, the smaller the angle is), the less internal rotation of the femur you will have available to you. An important fact if you are planning on squatting.
An easy way to do this is by approximating the angle of the femoral neck by performing “Craig’s Test”. Have your patient/client/athlete lie prone with their knee flexed 90 degrees. Palpate the greater trochanter (the bump on the side of the hip that the gluteus medius muscles attach to) with one hand while using the other hand to grasp around the ankle and internally and externally rotate the femur (we like to use the right hand on the right trochanter for the patient/client/athletes right leg). Note the position of the tibia when the greater trochanter is parallel to the table (see diagram above from Tom Michaud’s most excellent text: Human Locomotion: the conservative management of gait related disorders, available by clicking here). The smaller the angle, the more retro version/torsion present).
This is also a convenient way to estimate the amount of internal and external rotation of the femur available. One source states that internal rotation of greater than 70 degrees and external rotation of less than 25 degrees means that there is excessive femoral ante torsion present (1).
Craig’s Test: a convenient way to measure torsions of the femur. Important if you squat! Brought to you by The Gait Guys: Uber Gait Geeks Extrodinaire.
(1) Staheli LT. Rotational problems in the lower extremity. Orthop Clin North Am, 1987; 18:503-512