Question:medium
Identify the muscle marked causes flexion of hip [Images show axial and coronal CT sections of the abdomen/pelvis with a muscle marked bilaterally in the retroperitoneum]
Identify the muscle marked causes flexion of hip [Images show axial and coronal CT sections of the abdomen/pelvis with a muscle marked bilaterally in the retroperitoneum]
Show Hint
The muscle visible bilaterally in the retroperitoneum on CT, flanking the lumbar vertebrae, and inserting into the lesser trochanter is the primary hip flexor.
Updated On: Jun 23, 2026
- Gluteus Muscle
- Psoas Muscle
- Latissimus dorsi
- Multifidus
Show Solution
The Correct Option is B
Solution and Explanation
CT anatomy question: Identify the hip flexor muscle
Location on CT: retroperitoneal, bilateral, flanking the lumbar vertebral bodies = Psoas Major Muscle
Key facts:
Clinical relevance:
On CT: the psoas appears as a well-defined ovoid-to-triangular muscle mass in the retroperitoneum, merging with iliacus in the iliac fossa.
\[\boxed{\text{Answer: Psoas Muscle}}\]
Location on CT: retroperitoneal, bilateral, flanking the lumbar vertebral bodies = Psoas Major Muscle
Key facts:
- Origin: T12 to L5 vertebral bodies & intervertebral discs; transverse processes
- Insertion: Lesser trochanter of femur (combined with iliacus = iliopsoas)
- Innervation: Lumbar plexus (L1-L3); femoral nerve (L2-L4) for iliacus component
- Primary action: Hip flexion (most powerful hip flexor)
- Secondary: Lateral flexion of lumbar spine, stabilization of lumbar lordosis
Clinical relevance:
- Psoas abscess: presents with painful hip in fixed flexion (psoas sign); appears as a hypodense retroperitoneal collection tracking along the psoas on CT
- Psoas shadow: loss of psoas shadow on plain X-ray = retroperitoneal pathology (aortic aneurysm, haematoma, abscess)
On CT: the psoas appears as a well-defined ovoid-to-triangular muscle mass in the retroperitoneum, merging with iliacus in the iliac fossa.
\[\boxed{\text{Answer: Psoas Muscle}}\]
Was this answer helpful?
0
