Influence of a follower load on intradiscal pressure and intersegmental rotation of the lumbar spine.
METHODS
Intradiscal pressure and intersegmental rotation of human lumbar spines were measured in vitro.


OBJECTIVE
To determine the effect of a follower load on mechanical behavior at all levels of the lumbar spine.


BACKGROUND
Different loads have been proposed for studying the mechanical behavior of the lumbar spine. The influence of a follower load on intradiscal pressure at the different levels is unknown.


METHODS
Ten human cadaveric lumbar spines were loaded in the three main anatomic planes with pure moments of 3.75, 7.5, and 7.5 Nm plus a follower load of 280 N. Intradiscal pressure and intersegmental rotation were measured at all levels.


RESULTS
An additional follower load increased the intradiscal pressure, slightly reduced the intersegmental rotation for axial rotation, and hardly affected intersegmental rotation for lateral bending and flexion-extension.


CONCLUSIONS
A superimposed follower load renders spinal loading with pure moments more physiologic.
Rohlmann
A
A
Biomechanics Laboratory, Orthopaedic Hospital of the Free University of Berlin, Germany.
Neller
S
S
Claes
L
L
Bergmann
G
G
Wilke
H J
HJ
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology*; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D011312:Pressure; D016059:Range of Motion, Articular; D012399:Rotation; D013314:Stress, Mechanical