The pes cavus is a model of the human foot in which the sole of the foot is distinctly hollow when resting on the ground. That is, there is a permanent plantar flexion of the sole of the foot.

• In people with “pes cavus”, the medial longitudinal arch of the foot is exaggerated, and often the toes are clawed.
• The heel is mostly inverted (in varus) and the soft tissues of the sole are tight.
• People who have this condition will put too much weight and stress on the sole and heel of the foot when standing or walking.
• The plantar fascia will be contracted.
• Development of metatarsalgia and calluses.

Supination is a movement around an oblique axis and is a combination:

• Inversion
• Adduction
• Plantar flexion

Clinical presentation

• Metatarsalgia
• Plantar Fasciitis
• Painful calluses
• Lateral ankle instability
• Ankle arthritis
• Plantar flexion of the forefoot
• Achilles tendonitis
• Inverted heel (varus)
• External rotation of the knee
• Knee pain
• Stress fractures of the lower limbs
• Iliotibial band friction syndrome
• Hip pain
• Back pain

Causes

• High arched feet usually result from some kind of muscle imbalance associated with neuromuscular disorders such as:
  • Charcot-Marie-Tooth disorder
  • Poliomyelitis (most common cause)
  • Hereditary motor / sensory neuropathy
  • Cerebral palsy
  • Diastematomyelia
  • Muscular dystrophies, etc. Sometimes the deformation
• Secondary to trauma
  • Burns Contracture
  • Compartment syndrome

Symptoms

• Bone damage:
  • Structurally, the arch of the foot is too high to flex and absorb shock with a normal step, so that the heel bones (e.g. the calcaneus) and the sole of the foot (e.g. the metatarsals) are damaged during a normal use.
  • Normally, a foot flattens out with weight bearing, and its absence can lead to numerous injuries to the joints and long bones of the ankle and leg through the lower back.
  • Folded toes: Folded toes, also known as hammer toes or claw toes, can also develop.

Coleman test

• Coleman’s test assesses:
  • Rearfoot flexibility
  • Forefoot pronation
• The test is performed by placing the patient’s foot on a block of wood, 2.5 to 4 cm thick, with the heel and side edge of the foot on the block and bearing all of their weight while the first, second and third metatarsals are free to flex and pronounce.

Therapeutic approach

• Plantar orthosis if the foot is flexible