Femoral antetorsion is measured clinically by Ryder's test (Cusick & Stuberg, 1992).
| When the examiner palpates the greater trochanter (labelled "GT" in the figure to the right) with the hip in neutral rotation, it rests at a position that is slightly posterior to a frontal plane that passes through the acetabulum.
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| The examiner rotates the femur internally, moving the trochanter anteriorly until it protrudes laterally to the largest extent palpable. In this position, the goniometric measurement of hip internal rotation reflects the degree of femoral antetorsion.
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While Cusick and Stuberg (1992) state that the test's reliability is not established, their experience suggests that intertester differences avaerage about three degrees.
Some clinicians use the terms antetorsion and anteversion interchangably, but the distinction is important. Chris Smith is a podiatrist who discusses the distinction, and whose web-based tutorial on the topic is mirrored by Chris Kirtley, an Australian biomechanist who maintains an excellent web page on clinical gait analysis.
Reference:
Cusick, B.D., & Stuberg, W.A. (1992). Assessment of lower-extremity alignment in the transverse plane: Implications for management of children with neuromotor dysfunction. Physical Therapy, 72, 3-15.