This page describes the characteristics of various types of limps, beginning with the three which are most commonly observed in children. While intoeing is not a form of limp, it is a common gait-related concern in children and will be addressed in the section on differential diagnosis.
Imagine how you would walk if you had just stubbed your toe. This is the most common type of childhood limp and is associated with unilateral pain somewhere in the lower extremity. The child spends less time bearing weight on the affected limb. Watching and listening to the child's footfalls as they walk into the examination room will reveal asymmetry in the timing of the gait pattern.
Refusal to ambulate
Toddlers in particular may simply refuse to ambulate if ambulation causes pain. This is a severe form of antalgic gait. This makes the physical examination even more critical. A child who will crawl but refuses to walk may have pain in the foot or even an occult tibial fracture (termed a "Toddler's" fracture as this is a common injury in the new walker); the hips, femora and knees are likely unaffected.
In Trendelenburg gait, the child's shoulders and upper body shift laterally toward the affected side during that leg's stance phase. As a result, the upper body sways side to side; this is best observed as the child walks directly away from or towards you. This gait is associated with weak hip abductors which are incapable of keeping the pelvis level in single leg stance. The pelvis of the contralateral side drops during its swing phase (i.e. during single limb stance of the affected side). If you observe a swaying or waddling gait you must suspect and rule out hip pathology even if the symptoms appear to point more distally.
In steppage gait, the child flexes the hip and knee of the swing leg excessively so that the leg in swing phase looks like it is stepping up stairs. The foot then contacts the ground all at once (not with the heel first) as it drop onto the floor from above; this motion is called foot-drop and is associated with steppage gait. Steppage gait my be indicative of damage to the deep peroneal nerve or may point to an underlying neurological disorder such as cerebral palsy or hereditary motor sensory neuropathy.
Vaulting is associated with limb-length discrepancy or a stiff leg. In the case where one leg is longer than the other, the child spends much of the single limb stance of the shorter limb on tip toe. In this way the child's pelvis is lifted so that the longer leg can swing forward without dragging or catching a toe on the floor. Similarly during the swing phase of a stiff leg, the contralateral foot is on tip toe to minimize the knee flexion, hip flexion and/or ankle dorsiflexion required for the stiff leg to clear the floor. Vaulting differs from toe-walking as the heel does strike the floor normally. During vaulting, the child's centre of mass will bob up and down in a pronounced manner. Observe how the height of the child's pelvis changes throughout the gait cycle. Also observe each foot from the side during single limb stance. (Focus on one item at a time, don't try to watch both at once or you'll miss things.)