Assessment of gait disorders in children

Limp

Limp is defined as an asymmetric gait, and is a deviation from the normal gait pattern expected for a child's age. Causes can vary from benign to potentially life threatening (e.g., infection, tumours, child abuse). Appropriate evaluation requires an understanding and knowledge of normal and abnormal gait patterns, potential causes, and 'red flags'. [1] Beresford MW, Cleary AG. Evaluation of a limping child. Curr Pediatr. 2005;15:15-22. The assessment of limp will depend on whether the presentation is acute or not. [2] Kimura Y. Common presenting problems. In: Arthritis in children and adolescents: juvenile idiopathic arthritis. Szer I, Kimura Y, Malleson PN, et al (eds). Oxford: Oxford University Press; 2006:24-48.

Trauma is the most common cause of limp, although the potential for serious or life-threatening causes requires a thorough clinical assessment and appropriate investigations. Challenges in making a diagnosis include the possible difficulty in obtaining the history from the child's carer, a sometimes vague or not localised symptomatology, and a possible history of unwitnessed trauma.

Careful examination of all joints is necessary, as is general assessment including abdominal, neurological, and developmental assessments. [3] Foster HE, Cabral DA. Is musculoskeletal history and examination so different in paediatrics? Best Pract Res Clin Rheumatol. 2006;20:241-262.

Further information about paediatric musculoskeletal medicine, including red flags, video demonstrations of joint examinations (pGALS, pREMS), investigations, and referral guidance, is available at Paediatric Musculoskeletal Medicine (PMM). Paediatric Musculoskeletal Matters (PMM): an e-resource to aid teaching and learning about the essentials of paediatric musculoskeletal medicine

Normal motor milestones

[Figure caption and citation for the preceding image starts]: Normal motor milestones [Citation ends].

Persisting primitive reflexes beyond 6 months are suggestive of neurological problems such as cerebral palsy.

Normal gait patterns

The toddler has a broad base gait for support, and appears to be high stepped and flat footed, with arms outstretched for balance. The legs are externally rotated, with a degree of bowing. Heel strike develops at around 15 to 18 months with reciprocal arm swing. Running and change of direction occur after the age of 2 years.

In the school-age child, the step length increases and step frequency slows. Adult gait and posture occur around the age of 8 years. There is a considerable variation in normal gait patterns and the ages at which the changes occur; and appear to be family-history related. Black children tend to walk sooner and Asian children later than average.

Normal variations

• Leg alignment varies with age and is often influenced by a family history of the same pattern. [4] Sass P, Hassan G. Lower extremity abnormalities in children. Am Fam Physician. 2003;68:461-468.

• Habitual toe walking is common in young children up to 3 years. In-toeing can be due to persistent femoral anteversion and is characterised by the child walking with patellae and feet pointing inwards (common between the ages of 3 and 8 years).

• Internal tibial torsion is characterised by the child walking with patella facing forwards and toes pointing inwards (common from onset of walking to 3 years).

• Metatarsus adductus is characterised by a flexible 'C-shaped' lateral border of the foot. Most resolve by the age of 6 years.

• Bow legs (genu varus) are common from birth to early toddler-hood, often with out-toeing (maximal at approximately 1 year). Most resolve by 18 months.

• Knock knees (genu valgus). Often associated with in-toeing. Most resolve by the age of 7 years.

• Flat feet. Most children have a flexible foot with normal arch on tiptoeing. Flat feet usually resolve by the age of 6 years. [Figure caption and citation for the preceding image starts]: Flat feet and normal arches on tip toe From Dr Foster's personal collection; used with permission [Citation ends].

• Crooked toes. Most resolve with weight-bearing.

Causes for concern are if these normal variations are persistent (i.e., beyond the expected age range), if changes are progressive or asymmetric, or if there is pain and functional limitation or evidence of neurological disease.

In children with bow legs or knock knees, it is important to consider x-rays if the child is short (a height less than the 25th centile raises suspicions of hypophosphataemic rickets or skeletal dysplasias) or has genu varum or asymmetric leg alignment. [5] Greene WB. Genu varum and genu valgum in children: differential diagnosis and guidelines for evaluation. Compr Ther. 1996;22:22-29.

Abnormal gait patterns

Antalgic gait

• Reduced time spent weight-bearing on the affected side.

• Spectrum of possible causes (e.g., trauma to sole of foot, spinal osteomyelitis). Unwitnessed trauma is common in young children. The child presents with unwillingness to weight-bear, so an index of suspicion is required.

• May be observed in juvenile idiopathic arthritis (JIA), although children may not always complain of pain. [6] McGhee JL, Burks FN, Sheckels JL, et al. Identifying children with chronic arthritis based on chief complaints: absence of predictive value for musculoskeletal pain as an indicator of rheumatic disease in children. Pediatrics. 2002;110:354-359.

Circumduction gait ('peg leg')

• Excessive hip abduction as the leg swings forwards.

• Typically seen with a leg length discrepancy, with a stiff/restricted joint movement as in JIA, or with uni-lateral spasticity as in hemiplegic cerebral palsy.

Spastic gait

• Stiff, foot-dragging with foot inversion. This is often seen in upper motor neuron neurological disease (e.g., diplegic or quadriplegic cerebral palsy, stroke).

Ataxic gait

• Instability with an alternating narrow to wide base of gait.

• Seen in ataxic cerebral palsy affecting the cerebellum, cerebellar ataxia, and Friedreich's ataxia.

Trendelenberg's gait

• Results from hip abductor muscle weakness. While weight-bearing on the ipsilateral side, the pelvis drops on the contra-lateral side, rather than rising as is normal. With bi-lateral hip disease, this results in a waddling 'rolling sailor' gait with hips, knees, and feet externally rotated.

• May be observed in Legg-Calvé-Perthes disease, slipped capital femoral epiphysis, developmental dysplasia of the hip, JIA involving the hip, muscle disease (juvenile dermatomyositis or inherited myopathies), and neurological conditions (spina bifida, cerebral palsy and spinal cord injury).

Toe-walking gait ('equinus') with absent heel contact

• Habitual toe walking is common in children and associates with normal tone, range of movement around the feet and normal walking on request. However, persistent toe walking is observed in spastic upper motor neuron neurological disease (e.g., diplegic cerebral palsy) and may be a presentation of mild lysosomal storage disorder.

Stepping gait

• The entire leg is lifted at the hip to assist with ground clearance. Occurs with weak ankle dorsiflexors, compensated by increased knee flexion (i.e., a foot drop gait).

• Observed in lower motor neuron neurological disease (e.g., spina bifida, polio) and peripheral neuropathies (e.g., Charcot-Marie-Tooth disease).

'Clumsy' gait

• This term is commonly used to describe difficulties in motor coordination (fine and gross motor skills). The child may present with frequent falls, difficulty in self-help skills such as dressing or feeding at school. Poor handwriting and learning disabilities may be noted.

• It is important to exclude specific albeit mild neurological disabilities (cerebral palsy, cerebellar ataxia, or lower motor neuron disorders), indolent inflammatory arthritis or myopathies, and orthopaedic problems such as in-toeing. Metabolic disorders that may present with 'clumsy walking' should also be considered.