Trendelenburg Sign - Everything You Need To Know - Dr. Nabil Ebraheim скачать в хорошем качестве

Trendelenburg Sign - Everything You Need To Know - Dr. Nabil Ebraheim

Trendelenburg Sign The Trendelenburg test (or Trendelenburg sign) is used to assess the integrity of the hip abductor muscles. The Trendelenburg sign occurs due to dysfunction of the hip abductor muscles. The primary muscles responsible for hip abduction are the gluteus medius and gluteus minimus. The gluteus medius is the main abductor of the hip. Both the gluteus medius and minimus are innervated by the superior gluteal nerve. Their function—hip abduction—can be compromised by injury to the superior gluteal nerve. Abductor dysfunction can also result from an L5 nerve root injury or avulsion of the abductor muscles. Avulsion of the tendons of the gluteus medius and minimus at their insertion on the greater trochanter of the femur can lead to muscle weakness and loss of hip abduction. The function of the hip abductors is to maintain a level pelvis during single-leg stance—that is, when the patient is standing on one leg. When a person stands on both legs, each leg supports half the body weight. During single-leg stance, the supporting leg bears the full weight of the body. If the hip abductor muscles on the side of the supporting leg (the leg in contact with the ground) are functioning properly, the pelvis remains level and the trunk does not lean. If the abductor muscles of the supporting leg are injured or impaired, the patient will exhibit a positive Trendelenburg sign. For example, to test the right hip abductors, stand behind the patient and ask them to stand on their right leg. If the right hip abductors are intact, the pelvis remains level and the trunk does not lean. When the abductor muscles are functioning normally, they contract to maintain a level pelvis. If the hip abductors are weak or injured, standing on the affected leg causes the pelvis on the opposite (unaffected) side to drop downward. The trunk will lean toward the affected side. The weight of the unsupported leg and gravitational pull will tilt the pelvis downward away from the affected side. Because the abductor muscles are weak, they cannot counteract this tilt, which shifts the center of gravity. The patient may lose balance or instinctively compensate by leaning the trunk toward the affected side. Thus, three findings characterize a positive Trendelenburg sign: The affected abductor muscles are on the same side as the supporting leg (the leg in contact with the ground). The pelvis tilts downward away from the affected side. The trunk leans toward the affected side. This leaning of the trunk is like a friend stepping in to help—"lean on me"—because the abductor muscles on that side are weak and need assistance. You’ll observe that the pelvis drops away from the affected side, offering no help. In response, the trunk leans toward the affected side to aid in maintaining balance. The trunk compensates to stabilize the pelvis and preserve the center of gravity by shifting toward the weak side. Whether you're watching a Trendelenburg test video or examining a patient in clinic, observe the following: when the patient stands on one leg, does the trunk lean toward the supporting leg? Does the pelvis tilt away from that side? If yes, then the side the patient is standing on is the affected side, and the hip abductor muscles on that side are impaired. Quizzes 1. What is the primary muscle responsible for hip abduction? Gluteus medius Gluteus medius Gluteus maximus Piriformis Tensor fasciae latae Explanation: The gluteus medius is the main abductor of the hip, supported by the gluteus minimus. 2. Which nerve innervates the gluteus medius and minimus? Superior gluteal nerve Superior gluteal nerve Inferior gluteal nerve Femoral nerve Obturator nerve Explanation: The superior gluteal nerve innervates both the gluteus medius and minimus muscles. 3. What movement is compromised in Trendelenburg sign? Hip abduction Hip abduction Hip extension Hip flexion Hip internal rotation Explanation: Hip abduction becomes weak due to dysfunction of the gluteus medius and minimus. 4. Trendelenburg sign is most evident during which activity? Single-leg stance Single-leg stance Double-leg stance Sitting Running Explanation: The sign appears when the patient stands on one leg, stressing the hip abductors. 5. In a positive Trendelenburg sign, the pelvis tilts: Away from the affected side Away from the affected side Toward the affected side Stays level Rotates forward Explanation: Weak hip abductors fail to keep the pelvis level, causing it to drop on the opposite side. 6. Which spinal nerve root contributes to hip abductor innervation? L5 L5 L2 S1 T12 Explanation: The L5 nerve root forms part of the superior gluteal nerve, which innervates the abductors. 7. Avulsion of the abductor tendons occurs at which bony site? Greater trochanter Greater trochanter Ischial tuberosity Anterior superior iliac spine Pubic symphysis Explanation: Gluteus medius and minimus insert into the greater trochanter of the femur.