Herman J. Woltring

05-09-1990, 05:01 AM

Dear Biomch-L readers,

The last issue of the Journal of Orthopaedic Research (vol. 8, nr. 3, 1990)

contains a number of interesting articles:

William G. Negendank, Felix R. Fernandez-Madrid, Lance K. Heilbrun, and

Robert A. Teige, Magnetic Resonance Imaging of Meniscal Degeneration in

Asymptomatic Knees (pp. 311 - 320)

A. van Kampen and R. Huiskes, The Three-Dimensional Tracking Pattern of

the Human Patella (pp. 372 - 382)

M.P. Kadaba, H.K. Ramakrishnan and M.E. Wootten, Measurement of Lower

Extremity Kinematics During Level Walking (pp. 383 - 392)

In the context of the recent debate on joint angles, the latter two papers seem

to implement two different joint angle conventions: Albert van Kampen en Rik

Huiskes (Nijmegen/NL) implement the Selvik convention (flexion/extension imbed-

ded proximally, endo/exorotation floating, and ab/adduction imbedded distally),

while Murali Kadaba and his colleagues (West Haverstraw, NY/USA) have adopted

the Grood & Suntay definition with proximally imbedded flexion/extension axis,

floating ab/adduction axis, and distally imbedded endo/exorotation axis. They

call the corresponding joint angles even `orthopaedic angles'...

As Leendert Blankevoort (Nijmegen/NL) claimed in a recent paper in the Journal

of Biomechanics, the difference between these conventions is not very large.

However, flexion in his study did not go beyond about 90 degrees, if I recall

correctly, while knee flexions up to 150 degrees are reported in the present

Nijmegen study. It would be interesting to see how different the various curves

look under the two conventions.

In recent research with Sandro Fioretti in Ancona/Italy, we found that the heli-

cal angles and the Grood & Suntay angles are rather different for ab/adduction

and endo/exorotation, but quite similar for flexion/extension during regular

level walking, if the neutral attitudes are defined with the subject in the

standard, anatomical position. In fact, flexion/extension was similar for all

possible, Cardanic permutations, while the two other angles could be quite dif-

ferent. In one case where flexion/extension was the floating angle, the two

other angles were very large, presumably, because of a positive correlation

between the terminal angles when the floating angle is not small.

I'd like to pose the following question to the readership: it seems that there

are different interpretations of the terms `sagittal, frontal, and transverse

axes'. While Kapandji defines the sagittal and frontal axes to be horizontal

within the planes of the same names (again, for the subject in the standard,

anatomical position), others view these axes as normal to these planes. I would

be grateful for any comments and pointers to literature defining these alterna-

tives.

Herman J. Woltring, Eindhoven/NL

The last issue of the Journal of Orthopaedic Research (vol. 8, nr. 3, 1990)

contains a number of interesting articles:

William G. Negendank, Felix R. Fernandez-Madrid, Lance K. Heilbrun, and

Robert A. Teige, Magnetic Resonance Imaging of Meniscal Degeneration in

Asymptomatic Knees (pp. 311 - 320)

A. van Kampen and R. Huiskes, The Three-Dimensional Tracking Pattern of

the Human Patella (pp. 372 - 382)

M.P. Kadaba, H.K. Ramakrishnan and M.E. Wootten, Measurement of Lower

Extremity Kinematics During Level Walking (pp. 383 - 392)

In the context of the recent debate on joint angles, the latter two papers seem

to implement two different joint angle conventions: Albert van Kampen en Rik

Huiskes (Nijmegen/NL) implement the Selvik convention (flexion/extension imbed-

ded proximally, endo/exorotation floating, and ab/adduction imbedded distally),

while Murali Kadaba and his colleagues (West Haverstraw, NY/USA) have adopted

the Grood & Suntay definition with proximally imbedded flexion/extension axis,

floating ab/adduction axis, and distally imbedded endo/exorotation axis. They

call the corresponding joint angles even `orthopaedic angles'...

As Leendert Blankevoort (Nijmegen/NL) claimed in a recent paper in the Journal

of Biomechanics, the difference between these conventions is not very large.

However, flexion in his study did not go beyond about 90 degrees, if I recall

correctly, while knee flexions up to 150 degrees are reported in the present

Nijmegen study. It would be interesting to see how different the various curves

look under the two conventions.

In recent research with Sandro Fioretti in Ancona/Italy, we found that the heli-

cal angles and the Grood & Suntay angles are rather different for ab/adduction

and endo/exorotation, but quite similar for flexion/extension during regular

level walking, if the neutral attitudes are defined with the subject in the

standard, anatomical position. In fact, flexion/extension was similar for all

possible, Cardanic permutations, while the two other angles could be quite dif-

ferent. In one case where flexion/extension was the floating angle, the two

other angles were very large, presumably, because of a positive correlation

between the terminal angles when the floating angle is not small.

I'd like to pose the following question to the readership: it seems that there

are different interpretations of the terms `sagittal, frontal, and transverse

axes'. While Kapandji defines the sagittal and frontal axes to be horizontal

within the planes of the same names (again, for the subject in the standard,

anatomical position), others view these axes as normal to these planes. I would

be grateful for any comments and pointers to literature defining these alterna-

tives.

Herman J. Woltring, Eindhoven/NL