The Trendelenberg Sign [HD]

The Trendelenberg Sign [HD]

The Trendelenberg Sign results from unilateral
disrupted function of the primary abductor muscles of the hip –gluteus minimus and gluteus
medius. Both muscles are innervated by the superior gluteal nerve, and their function
can be compromised by damage to the nerve resulting from hip dislocation,
hip surgery, or motor neuron disease such as poliomyelitis, direct damage
to the muscle bellies, or avulsion of their distal attachment from the femur can lead weakness
or loss of hip abduction. The Trendelenberg Sign is most apparent during
the walking gait cycle. When the weight of the body is supported by the leg on the lesioned
side, the pelvis “rises” ipsilaterally. In fact, this more accurately described as
a dipping of the pelvis toward the contralateral side. Because the pelvis cannot be maintained
in a level plane by the lesioned abductors, the patient “falls” toward the good side
and simultaneously leans the torso toward the lesioned side in an attempt to maintain
balance. The mechanics behind the Trendelenberg Sign
are difficult but can be made easier by first reviewing
basic principles of joint movements. Joint movements can be described in two different
ways, depending upon which skeletal elements are “fixed” or immobile. For instance,
performing a dumbbell curl is an example of elbow flexion. More specifically, this motion
can be described as “flexion of the forearm at the elbow joint.” The bones of the forearm
are in motion, while the humerus is relatively immobile –held in place by the muscles of
the shoulder and chest. Likewise, performing a pull-up is also an
example of elbow flexion. Now, however, we can describe the movement as “flexion of
the humerus at the elbow joint.” The humerus is in motion while the bones of the forearm
are immobilized by the fixation of the hands to the bar. By applying
this principle to the movement of hip abduction, we can better appreciate how the Trendelenberg
Sign comes about. Hip abduction is the responsibility of gluteus
medius and gluteus minimus, both of which are attached proximally to the pelvis and
distally to the femur. Typically, hip abduction is visualized as raising the lower limb away
from the body in a lateral direction, thereby making the angle between the thigh and torso
more acute. During this type of hip movement –described as “abduction of the femur
at the hip joint”- the pelvis remains fixed, while the femur is pulled laterally by the
contraction of gluteus medius and minimus on that side.
However, we know that we can also achieve hip abduction in the opposite direction: that
is, by tilting the pelvis laterally. This motion also decreases the angle between the
thigh and the torso, and can be described as, “abduction of the pelvis at the hip
joint”. Both of these examples of hip abduction depend on proper function of the gluteus medius
and minimus muscles. In fact, raising the leg laterally while standing requires the simultaneous action of the abductors
on BOTH sides of the body. Obviously, the abductors on the right are contracting in order
to raise the right lower extremity. But at the same time, the abductors on the left
side –the supporting side- are contracting in order to immobilize the pelvis and maintain
it in a neutral plane. They are, in fact, pulling the pelvis laterally in order to offset
the weight of the unsupported right leg. This action, abduction of the hip on the side that
is supported by contact with the ground, is KEY to understanding the Trendelenberg Gait. Let’s examine the normal walking gait. When
the person’s weight is supported by the left leg, the right leg is unsupported
as it swings forward. The weight of the unsupported right leg should tilt the pelvis
downward towards the right side. However, the abductors on the left side offset this
action by pulling the pelvis towards the fixed and stable left leg, thereby maintaining
the pelvis in a neutral or non-tilted plane. Now, Let’s compare that with the walking
gait of someone with paralyzed hip abductors on the left side.
When this person’s weight is supported by the left leg, and the right
leg is unsupported as it swings forward, the paralyzed hip abductors on the left side are
unable to offset the weight of the right leg. This causes the pelvis to tilt downward, throwing the body’s center of gravity off.
In order to counteract this imbalance, these persons will often maintain their center of
gravity by leaning their torso back to the left each time the right leg is unsupported.
This seems like a relatively simple concept, but confusion can set in unless you remember
that the dysfunctional abductor muscles are on the same side as the supporting leg. The simplest way to assess the integrity of
the hip abductors in the clinic is to ask your patient to stand motionless on one leg.
If the hip abductors connected to the supporting leg are intact, the pelvis will remain level
and the torso will not lean toward the supported side of the body. If, on the other hand, the
abductors of the supporting leg are injured, the patient exhibit the Trendelenberg sign. The pelvis will tilt away from the supported side and the patients will either lose their balance or try to maintain their center of gravity with a compensatory leaning of the torso toward the side of injury.

100 Replies to “The Trendelenberg Sign [HD]”

  1. im sorry i dont understand this part, why should the pelvis tilt downward on the swing limb?, its being raised from the ground so it should take the pelvis upward with it, right?

  2. I am in my clinical rotation for my associates for physical therapy assistant. For 5 months I have been searching for this masterpiece!!! Thank you so very much!!! I am such a visual learning it's ridicules!!! THANK YOU THANK YOU THANK YOU!!!

  3. After the first few seconds I thought, "great another unclear video". But then I watch it until the end and boy am I glad I did because you nailed it. Thank You! Moral of story…WATCH THE ENTIRE VIDEO

  4. And …what can we do about this situation?
    It's really a nasty thing
    I have it and I can not walk for longer periods
    It hurts and get worse when I keep on walking,or moving to much
    Can you please please tel what to do about this??????????????
    Thank you sooo very much

  5. Terminé aquí después de conocer la posición de trendelemburg en anafilaxia. Muy bien explicado y los gráficos excelentes.
    Entendí todo, pero si pueden poner sub en español llegaría a más gente

  6. So I understand the gait problem. What is the remedy for treatment? How do I get better stability? Therapy? Pills/ medications? A robot? A shot ? What can help me walk better? Please Please

  7. Can you please correct the name of the test?
    Friedrich Trendelenburg
    German surgeon. Besides that, a sign is someting that u see. You showed a trendelemburg gait. Something dynamic.

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