Interpretation
(a) The response is NORMAL (i.e. the test is “negative”)
if the pelvis on the non-stance side can be elevated
as high as hip abduction on the stance side will allow,
and providing this posture can be maintained for 30
seconds with the vertebra prominens centred over the hip
and foot.
(b) The response is ABNORMAL (i.e. the test is
“positive”) if this cannot be done. This includes
responses where the pelvis is elevated on the non-stance
side above the stance side, but where this elevation is not
maximal.
(c) The response is also ABNORMAL if the pelvis can be lifted on command, but can not be maintained in
that position for 30 seconds. The time taken before the
pelvis starts to fall is recorded. By introducing a time element,
the Trendelenburg test can be objectively recorded
for comparison purposes. Obviously the response
described in (b) constitutes a zero time Trendelenburg
test.
Non-valid responses. In the presence of back or leg pain
or of deformity. or if the patient is uncooperative
because ofage or mental status, inappropriate responses
may arise (Table II). An abnormal response (positive
test) in these circumstances can be misleading. However,
ifthe test is negative that is significant-it means that the
subject does not have abnormal hip mechanics.