Defect in Gluteus Maximus lead to all of the following, EXCEPT?
**Core Concept**
Gluteus Maximus is the largest muscle of the buttock, responsible for hip extension and external rotation. A defect in this muscle can lead to various clinical consequences, affecting the patient's gait, balance, and overall mobility.
**Why the Correct Answer is Right**
Gluteus Maximus plays a crucial role in stabilizing the pelvis and facilitating movements such as standing up from a seated position, climbing stairs, and maintaining balance. A defect in this muscle can lead to a Trendelenburg gait, where the pelvis drops on the unaffected side when the patient stands on the affected limb. This is due to the inability of the gluteus maximus to stabilize the pelvis and maintain proper alignment.
**Why Each Wrong Option is Incorrect**
* **Option A:** Weakness in hip abduction. This is incorrect because gluteus medius and gluteus minimus are primarily responsible for hip abduction, not gluteus maximus.
* **Option B:** Abnormal gait. This is correct, as a defect in gluteus maximus can lead to an abnormal gait, including a Trendelenburg gait.
* **Option C:** Muscle weakness in knee extension. This is incorrect because gluteus maximus primarily affects hip extension, not knee extension, which is primarily a function of the quadriceps muscle.
* **Option D:** Abnormal lumbar lordosis. This is incorrect because gluteus maximus primarily affects the hip joint, not the lumbar spine, which is responsible for maintaining normal lumbar lordosis.
**Clinical Pearl / High-Yield Fact**
Remember that the Trendelenburg sign is a classic indicator of gluteus maximus weakness, where the pelvis drops on the unaffected side when the patient stands on the affected limb.
**Correct Answer: D. Abnormal lumbar lordosis.**