Practitioners use certain terms to describe positional variations of the lower extremities and are often used in the nomenclature of specific orthopedic conditions.

In general, the joint that is primarily involved in the condition constitutes the first word; the subsequent word or words relate to the positioning of the extremity relative to the midline of the body. For example, coxa vara is a condition of the hip (coxa) that results in a deviation of the leg toward the midline (varus position). The orthopedic terms in BOX 183-1 have special reference to abnormalities of the feet and legs.

BOX 183-1: Glossary of Terms That Refer to Foot and Leg Abnormalities

• Abduction: deviation away from the midline of the body
• Adduction: deviation toward the midline of the body
• Calcaneus: foot dorsiflexed, placing the heel below the level of the toes
• Cavus: medial longitudinal arch of the foot elevated
• Equinus: foot plantar flexed, placing the toes below the level of the heel
• Pes: the foot
• Planus: medial longitudinal arch of the foot flattened
• Talipes: congenital deformities of the foot that, if untreated, result in walking on the ankle (talus)
• Torsion: excessive or abnormal twisting along the long axis
  • Internal torsion: excessive or abnormal inward twisting
  • External torsion: excessive or abnormal outward twisting
• Varus: medial or inward deviation of one segment of an extremity relative to the proximal (previous) segment
• Valgus: lateral or outward deviation of one segment of an extremity relative to the proximal (previous) segment
• Version: physiologic or normal twisting along the long axis
  • Inversion: physiologic or normal twist inward
  • Eversion: physiologic or normal twist outward
  • Anteversion: physiologic or normal twist forward
  • Retroversion: physiologic or normal twist backward