Frog-leg position
Frog-leg position
seen in
[A] Rheumatoid arthritis
[B] Cauda equina syndrome
[C] Intramedullary tumor of Spinal cord
[D] Caudal regression syndrome
Conditions where frog-leg position is typically seen:
- Rickets 🦴
- Children with rickets often lie in a frog-leg position because of muscle weakness and soft bones, especially at the hips and knees.
- It helps them feel more comfortable and reduces strain on weak lower limb muscles.
- Developmental Dysplasia of the Hip (DDH) 👶
- The frog-leg position is used both spontaneously by infants with hip laxity and deliberately in X-rays (frog-leg lateral view) to evaluate hip joints.
- Neuromuscular Disorders (e.g., spinal muscular atrophy, poliomyelitis, myopathies)
- Weakness of the hip and thigh muscles causes legs to fall outward into a frog-leg posture.
- Cerebral Palsy (Hypotonic type)
- Hypotonic infants may lie in a frog-leg position due to poor muscle tone and inability to hold legs together.
✅ Classic Teaching
- Rickets → child lies in frog-leg posture.
- Infantile hypotonia / SMA / DDH → frog-leg position is a clue.
- Radiology → frog-leg lateral X-ray view of hips.
Caudal regression syndrome – also called as
-
- sacral agenesis
- hypoplasia of the sacrum
Frog-leg position: child’s legs bend with their knees pointed outward and their feet in line with their hips.
Can be seen in –
CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons
Antero-posterior radiographic view, showing missing ribs, absent lumbosacral vertebrae, hypoplastic pelvis and “frog-like” position of the lower extremities.


