Laboratory Studies
Measurement of serum creatine phosphokinase (CPK) may be useful to confirm muscle disease as the suspected etiology of toe walking. CPK levels are markedly elevated in Duchenne muscular dystrophy (DMD).
Imaging Studies
Although no formal imaging studies are required for a routine evaluation of toe walking, the studies discussed below may be used to gain more insight into the etiology of this condition.
Plain radiography
Standing anteroposterior (AP), lateral, and oblique radiographs of the feet are obtained to provide a more objective assessment of ankle equinus and rule out a possible bony foot or ankle abnormality as a cause for the toe walking.
In a patient with muscle spasticity that is not secondary to cerebral palsy (CP) or in a patient with isolated lower-extremity weakness, posteroanterior (PA) and lateral radiographs of the thoracolumbar spine are indicated to rule out bony abnormalities that may suggest a spinal-cord abnormality. Large posterior-element defects and a widened distance between pedicles might indicate an intraspinal anomaly.
Magnetic resonance imaging
If the findings from plain radiography are positive or if clinical suspicion of a focal neurologic abnormality is high, magnetic resonance imaging (MRI) of the spinal cord, the brain, or both should be obtained as a definitive screen for the possibility of a focal pathologic process in the central nervous system. MRI of the spine in younger patients invariably necessitates sedation services to allow a good-resolution study.
Other Tests
Additional diagnostic tests are not routinely required for the evaluation of toe walking; their use is guided by the specific clinical scenario. Some controversies exist regarding the widespread use of electromyography (EMG) and gait analysis in diagnosis. However, both evaluations may be helpful in select patients.
Electromyography
EMG may be performed if the family history or clinical symptoms are suggestive of hereditary sensorimotor neuropathies. Dynamic EMG data can also be obtained from surface or intramuscular electrodes so that muscle activity can be correlated with the phases of the gait cycle. It has been shown that children with idiopathic toe walking (ITW) and CP have premature activation of the gastrocnemius muscles during the swing phase of gait as compared with normal children, in whom activation is seen only in the stance phase. [38]
EMG can also differentiate ITW from CP. Children with CP demonstrate coactivation of the gastrocnemius-soleus complex along with the quadriceps muscles during stance, whereas children with ITW do not. [39, 40]
Gait analysis
Although formal computerized motion analysis facilities are not universally available, several studies have shown that such analysis can help distinguish ITW from mild CP when the distinction is not readily apparent on physical examination. [41, 42, 43]
O'Sullivan et al carried out a gait laboratory review of 102 patients who presented with a presumptive diagnosis of ITW. [44] Through analysis, they found that 81 (79.4%) of the cases had data that agreed with this presumptive diagnosis, whereas 21 (20.6%) were not typical of this diagnosis. There were significant differences between the groups with respect to Babinski response, fast stretch of the gastrocnemius, knee flexion at initial contact, and asymmetry at the ankles during gait.
This study highlighted the useful applications of this noninvasive means of diagnosis, which can help guide appropriate treatment while avoiding inappropriate procedures. [44] Gait analysis can also be particularly helpful in a patient whose toe walking has a spastic etiology, in that it helps separate the multiple joint and muscle contributors to the observed gait. For example, gait analysis can help determine whether toe walking is caused by ankle plantarflexor spasticity alone or by a combination of muscle spasticity at the knee and hip.
Toe-walking tool
The toe-walking tool is a reliable and validated 28-item questionnaire designed to aid practitioners in identifying underlying medical conditions that lead to a toe-walking gait. It can be the primary focus of an algorithmic approach to the evaluation of a patient with toe walking. [45]
Auditory feedback
An auditory feedback system to assist in gait rehabilitation of CP patients with dynamic toe walking has been developed. Based on plantar pressure monitors embedded in shoes, this system can monitor toe-walking strides in real time and produce an auditory signal to alert patients when toe walking has been detected. Although this system was designed to identify toe-walking strides in children with CP, its use may also be expanded in the future to provide a behavior-modifying feedback system for children with ITW. [46]
Procedures
Muscle biopsy is a surgical procedure previously used to confirm muscle disease as the suspected etiology of toe walking. [25] Currently, muscle biopsy is rarely used in this setting, because genetic tests are increasingly capable of offering similar information without the associated procedural morbidity.
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Articulated molded ankle-foot orthosis (AFO). This cosmetic appliance fits into regular shoe. It allows free dorsiflexion but prevents plantarflexion and, hence, toe walking.
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Idiopathic toe walking in 10-year-old boy: rear and side views.
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Idiopathic toe walking in 10-year-old boy: closeup view.
