It may be unilateral or bilateral.
Cause of bilateral pes cavus:
• Charcot–Marie–Tooth disease.
• Friedreich’s ataxia.
• Muscular dystrophies.
• Spinal muscular atrophy.
• Cerebral palsy.
• Syringomyelia.
• Hereditary spastic paraparesis.
• Spinal cord tumour.
Cause of unilateral pes cavus:
• Old poliomyelitis.
• Spinal trauma.
• Spinal cord tumour.
• Mal-union of calcaneus or talus fracture.