August 2012

Idiopathic toe walking: Insights on intervention

As researchers explore the possibility that idiopathic toe walking has an underlying neurologic cause, clinicians continue to refine treatment strategies to keep ITW patients off their toes. Orthotic devices play a key role, with lower-profile devices growing in popularity.

By Emily Delzell

New research suggests that idiopathic toe walking, long considered a gait pattern that occurs in the absence of other abnormalities, may have an underlying neurological cause. Investigators need to under­take much more research to confirm this early hypothesis, but, until more is known, researchers suggest that clinicians be alert for subtle signs of other sensory and motor skills issues in children with the diagnosis.

It’s normal for toddlers to walk on their toes as their gait devel­ops, but when this pattern persists in children older than two years, it’s a cause for concern. Toe walking can be the first sign of neuro­log­ical or developmental condition such as cerebral palsy or autism spectrum disorder.1 In addition, bilateral toe walking is often seen in children with congenital muscular dystrophy and global de­velopmental delay. (Unilateral toe walking is typically the result of trauma.)2

“Ultimately, the diagnosis is given when there is no medical reason for toe walking,” said Cylie Williams, PhD, a podiatrist with Southern Health, Cardinia Casey Community Health Service, Cran­bourne, Australia.

Williams and her colleagues have developed the Toe Walking Tool, a validated 25-item questionnaire that can help practitioners identify otherwise healthy children who toe walk as well as reveal risk factors for other medical conditions that may require further evaluation from a specialist.2

Although Williams’ tool is used to rule out these well-charac­terized conditions, her recent work has lead her to suspect the gait pattern may not be truly idiopathic, but instead, “the result of some very mild neurological changes we still don’t understand.”

Williams noted that several studies3-5 have described increased sensitivity to vibration and hypersensitivity in the hands or feet in children and adults with Asperger syndrome and autism spectrum disorder and that gait changes, including toe walking in children, are linked to these disorders.6

In 2010 Williams and her colleagues completed a literature review on the relationship between toe walking and sensory processing dysfunction.7 They found only a handful of studies that discussed a potential link between ITW and sensory processing issues, but noted that clinical observations and anecdotal reports of the possibility of such a connection were becoming more common.7

To test whether children diagnosed as idiopathic toe walkers might also demonstrate changes in sensory processing, Williams and her colleagues recruited 30 healthy children aged 4 to 8 years who were not toe walkers (NTW) and 30 children in the same age range who the researchers identified as current idiopathic toe walkers using the exclusionary toe-walking tool.

They measured the children’s vibration perception threshold (VPT) in the right hallux using a vibratory sensory analyzer that delivers a frequency vibration of 100 Hz (amplitude range, 0-130 µm) through a Teflon-coated pin mounted in a footplate (Figure 1). The vibration mimics the everyday tactile input that allows the brain to sense fine surface texture changes, which, in the feet, play a key role in protection and proprioception.8

The results, e-published in March by the Journal of Child Neuro­logy, showed that the children in the toe-walking group had a significantly lower VPT than those in the NTW group (mean, 1 µm vs 1.8 µm; P = .001).

Figure 1. Foot in position for vibration perception analysis by Williams et al. (Image courtesy of Cylie Williams, PhD.)

“The vibration study paper highlighted a difference in tactile sensory perception, or heightened feelings of touch, that the children with ITW had, indicating that these children were perhaps more sensitive in some way to touch,” Williams said. “We tested this as part of a larger study of the motor skills and sensory processing abilities of children who have an ITW gait. The rest of the results are being finalized for publication, but we found that children who had an ITW gait had problems with some specific gross motor skills and displayed some unusual behavioral changes as a result of different sensory input. This result indicated there might be some immaturity or difference in the way the children who have an ITW gait process sensory input.”

During data collection for the larger study the Australian researchers turned up an unexpected finding that also hinted at some neurological basis for ITW.9 They recorded the preferred hand of each child in the ITW and NTW groups and found that only 10% of the children in the NTW cohort preferred their left hand, a result that is in line with population norms.9 In contrast, 33% of the children in the toe-walking group preferred their left hand.9 Previous research has linked left handedness to difficulty with spatial tasks and dyslexia.10-12

“The left-handedness result also feeds into this [the theory that children with ITW may have a mild neurological condition], and, while the children may be genetically left handed, there is also the possibility that the left handedness is neurologically based,” Williams said. “This result again points to the ITW gait being the result of some mild neurological impairment. The study on this cohort of children who appeared to be neurologically normal but toe walked found that there were all these interesting little signs that, in fact, the toe walking may actually be the result of some very mild neurological changes—but we’re still not sure what these might involve.”

Figure 2. An 8-year-old child with a history of toe walking is fitted for a custom SMO with a plantar flexion stop. (Image courtesy of Kevin Matthews, CO, LO.)

Pähr Engström, MD, is a consulting orthopedic surgeon at Astrid Lindgren Children’s Hospital in Stockholm and a PhD candi­date in the Division of Pediatric Neurology, Karolinska Institutet, also in Stockholm, who will defend a thesis on ITW in December. Engström has authored several studies on the condition, including one currently in press that examines neuropsychiatric problems and symptoms in children with ITW.

Engström told LER, “I also believe ITW is mainly neurogenic. But at present we do not know. As much else about ITW, this is just a theory. As Williams et al conclude in their review about sensory processing, there are no studies yet that can say that sensory pro­cessing is a cause of ITW, but that does not mean it is not so. ITW children do have more neuropsychiatric problems13 [than children without the condition] and that is probably an indication of a neurogenic origin. More studies are needed!”

The takeaway from this work, Williams said, is a need for healthcare providers to consider the whole child rather than their gait pattern alone.

“There may be social and behavioral concerns that impact the child, especially in the area of sensory and gross motor skills. Health­­care providers also need to give parents realistic expecta­tions of treatments, as there is no current evidence to support any one treatment as being 100% effective and this neurological reason may be why,” she said. “Often the treatment used for kids with ITW focuses on tight gastroc and soleus muscles, and, while this is a continuing priority, consideration should be given to other problems and a referral to occupational therapist, neurologist, pediatrician, or child psychologist may be in order.”

Treatment

Treatments for ITW include stretching exercises, serial casting, ankle foot orthoses (AFOs), night splints, surgical lengthening of the triceps surae muscle complex, and, most recently, botulinum toxin A injections, which result in a temporary flaccid muscle paralysis.14

Two small case series have tested the effect of botulinum toxin A (Botox) in ITW. In 2004 Jacks et al treated 10 children aged 2 to 17 years with a single injection of botulinum toxin injection followed by night splinting; toe walking resolved in seven of the 10 children.15

Brunt et al reported on a series of five children with ITW who underwent bilateral botulinum toxin injection in the gastrocnemius and soleus muscles. Their goal was to retrain the muscles and normalize ankle function as measured by electromyography. Twenty days after injection the children received physical therapy to the gastroc-soleus muscles.16

Before injection initial contact was limited to the toe or was digitigrade in 51% of the children; at 20 days post-treatment only 8% of the children’s foot contacts were toe or digitigrade. Before treatment gastrocnemius onset occurred a mean of 30 ms before foot contact and the duration of swing phase tibialis anterior activa­tion was attenuated (345 ms). After treatment gastrocnemius onset occurred a mean of 36 ms after foot contact and duration of tibialis anterior activation increased through terminal swing and into the loading response phase. The post-treatment improvements were maintained at 12-month follow up.16

Engström and colleagues examined the effects on gait of botuli­num toxin injection followed by stretching exercises for the calf muscles five days a week plus at least 50 heel-to-toe steps per day. The 15 children (aged 5-13 years, five girls) were toe walkers and were examined by a pediatric neurologist to confirm the absence of underlying neurological or muscular pathology. Patients received four injections of botulinum toxin A in each calf, two in the proximal third of the lateral and medial gastrocnemius bellies and two distally in the gastroc-soleus complex.14

The children underwent 3D gait analysis and passive range of motion measurement prior to treatment and at three weeks and three, six, and 12 months after injection. Parents also rated their perceptions of the amount of toe walking before treatment and at six- and 12-month follow up (only 11 children were available at 12-month follow up).

At 12-month follow up parents reported that three children had completely stopped toe walking and four had decreased their amount of toe walking by 25% to 50%. In four children the amount of toe walking was unchanged. After six to 12 months, nine of the 14 children for whom data could be assessed experienced improve­ments in toe-walking severity classification.

Gait analysis for the entire group showed all children had a significant improvement in the amount of ankle dorsiflexion achieved in stance; however, Engström noted, almost all the child­ren’s ankles after treatment were still in a plantar flexed position.

“The obvious goal of ceasing toe walking was only occasionally reached,” Engström said. “This is a nonrandomized study with only 15 participants, so it is hard to draw many conclusions, but I am doubt­ful that Botox has a place in management of ITW. We are conducting a randomized controlled trial comparing plaster casting alone with a com­­bination of plaster and Botox that will show more reliable results.”

A 2012 review article by Oetgen at al reported that the results of nonsurgical management of ITW are mixed, but that conservative interventions (including stretching exercises, serial casting, and botulinum toxin injections) have been most successful in patients with a baseline ankle dorsiflexion greater than or equal to 0°.15

Oetgen et al concluded that surgery, which lengthens the triceps surae muscle-tendon complex, should be reserved for patients with fixed equinus contractures or those who do not respond to conservative treatment.

Only one patient in Engström’s study had a fixed equinus contracture; that child eventually underwent surgical lengthening, which produced favorable results.13 Engström’s group reported that they now regard fixed contractures as a contraindication for botulinum injection.14

“The studies with the highest level of evidence support the use of serial casting and surgery, but there is limited evidence these change the gait pattern in the long term,” Williams said. “These interventions do, however, change the length of the gastroc and the soleus and I believe that is an important consideration—we know that adults with a tight gastroc and soleus resulting from other conditions [besides ITW] have more foot pain and a lower quality of life,17-20 and I believe this needs to be considered when treating children who toe walk. I also believe the most conservative treatment options should always be the first port of call.”

Orthotic options

Orthotists have reported good results with AFOs, and, more recently, with even more minimal devices.

Research presented at the American Academy of Orthotists and Prosthetists annual meeting in March, for example, suggested that treating children who are toe walkers with a rigid footplate may yield better long-term outcomes than using an AFO—the traditional and more restrictive orthotic treatment for ITW (See “Off their toes: Lower profile device aids toe walkers”).

The results of that research showed that children who wore a full-length carbon-fiber footplate tended to have a better carryover effect once out of the device than children who wore an articulated AFO that completely blocked plantar flexion at the ankle joint.

Mark Geil, PhD, an associate professor of biomechanics at Georgia State University in Atlanta who presented the results, noted, “The footplate still allows children to toe walk if they try. The better carryover we saw with the less restrictive device led me to what I call ‘the rebellious teenager theory.’”

That is, the more restrictive device resulted in more regression because children don’t accept total restriction as easily as more gentle orthotic encouragement.

Orthotist Kevin Matthews, CO, LO, owner of Advanced Ortho­pe­dic Designs in San Antonio, TX, also prefers the minimalist approach to orthosis design for ITW. He reports excellent success using a custom supramalleolar AFO modified with a plantar flexion stop (Figure 2).

“Walking on their toes feels natural to these children, but when we cue them to walk on their heels, most can do that. So, if they can heel walk and they have normal tone, they’re a candidate for this design,” he said.  “The traditional designs for this condition are hinged AFOs with a plantar flexion stop that goes almost all the way up to the knee. It’s a lot brace of to wear, and it forces the child to walk in a heel-toe gait pattern.”

Matthews, who has fabricated more than 100 pairs of the low-profile SMO for children with ITW, maintains that encouraging rather than forcing the child into a normal gait pattern means patients use their own muscles to walk rather than relying on the brace.

“The SMO helps them establish a new gait pattern on their own and this device is much less visible than a hinged AFO—only about two inches stick out of the back of the shoe and the sides—so it’s not obvious at first glance that the child is wearing a brace,” he said.

Matthews said he had heard about the use of the rigid carbon footplate to treat toe walking, but has been hesitant to try it.

“I have offered it to a few patients, but as yet no takers. It would help to have more information published on the approach. These are not covered by insurance and we charge $60 each,” he said. “The approach makes sense and I feel it may well be a viable option and have told my patients that. My concern is that it doesn’t impact all phases of gait—their [the Georgia State researchers] results are nowhere near as good as I have been getting.”

He is confident enough in the modified SMO design to offer parents a no-risk deal: if parents aren’t happy with device at any point during the six month treatment, he’ll fabricate the more expensive hinged AFO at no cost. He says he’s only had to do this once.

“I replaced it [the SMO] with an AFO on the physical therapist’s recommendation,” he says. “The patient was compensating by flex­ing at the knee to walk on his toes. I was sure he would not continue to do so, but they requested the AFO and I didn’t argue the point.”

Matthews noted, however, that children must wear the SMO during all waking hours to be effective and, if the parents aren’t willing to enforce this wear, the brace is not a good option for their child.

“My goal is to use the minimal intervention that is effective. For children who toe walk, this little brace works superbly,” he said.

REFERENCES

1. Oetgen ME, Peden S. Idiopathic toe walking. J Am Acad Orthop Surg 2012;20(5):292-300.

2. Williams CM, Tinley P, Curtin M. The Toe Walking Tool. A novel method for assessing idiopathic toe walking children. Gait Posture 2010;32(4):508-511.

3. Guclu B, Tanidir C, Mukaddes NM, Unal F. Tactile sensitivity of normal and autistic children. Somatosens Mot Res 2007;24(1-2):21-33.

4. Blakemore SJ, Tavassoli T, Calo S, et al. Tactile sensitivity in Asperger syndrome. Brain Cogn 2006;61(1):5-13.

5. Cascio C, McGlone F, Folger S, et al. Tactile perception in adults with autism: a multidimensional psychophysical study. J Autism Dev Disord 2008;38(1):127-137.

6. Barrow WJ, Jaworski M, Accardo PJ. Persistent toe walking in autism. J Child Neurol 2011;26(5):619-621.

7. Williams CM, Tinley P, Curtin M. Idiopathic toe walking and sensory processing dysfunction. J Foot Ankle Res 2010;3:16

8. Williams CM, Tinley P, Curtin M, Nielsen S. Vibration perception thresholds in children with idiopathic toe walking gait. J Child Neurol 2012 Mar 20. [Epub ahead of print]

9. Williams CM, Tinley P, Curtin M, Nielsen S. Hand preference in children with n idiopathic toe walking gait. Acta Paediatr 2012;101(3):e140-141.

10. Peters M, Reimers S, Manning JT. Hand preference for writing and associations with selected demographic and behavioral variables in 255,100 subjects: the BBC internet study. Brain Cogn 2006;62(2):177-189.

11. Snyder PJ, Harris LJ. Handedness, sex, and familial sinistrality effects on spatial tasks. Cortex 1993;29(1):115-134.

12. Lewis C, Hitch GJ, Walker P. The prevalence of specific arithmetic difficulties and specific reading difficulties in 9- to 10- year-old boys and girls. J Child Psychol Psychiatry 1994;35(2):283-292.

13. Engström P, Van’t Hooft I, Tedroff K. Neuropsychiatric symptoms and problems among children with idiopathic toe-walking. J Ped Orthop 2012 (In press).

14. Engström P, Gutierrez-Farewik EM, Bartonek A, et al.  Does botulinum toxin A improve the walking pattern in children with idiopathic toe-walking? J Child Orthop 2010;4(4):301-308.

15. Jacks Kl, Michels Dm, Smith BP, et al. Clinical usefulness of botulinum toxin in the lower extremity. Foot Ankle Clin 2004;(2):339-348.

16. Brunt D, Woo R, Kim HD, et al. Effect of botulinum toxin type A on gait of children who are idiopathic toe walkers. J Surg Orthop Adv 2004;13(3):149-155.

17. Hill CL, Gill TK, Menz HB, Taylor AW. Prevalence and correlates of foot pain in a population-based study: the North West Adelaide health study. J Foot Ankle Res 2008:1;2.

18. Irving DB, Cook JL, Young MA, Menz HB. Impact of chronic plantar heel pain on health-related quality of life. J Am Podiatr Med Assoc 2008;98(4):283-289.

19. Maskill D, Bohay DR, Anderson JG. Gastrocnemius recession to treat isolated foot pain. Foot Ankle Int 2010;31(1):19-23.

20. Lavery LA, Armstrong DG, Boulton AJ. Ankle equinus deformity and its relationship to high plantar pressure in a large population with diabetes mellitus. J Am Podiatr Med Assoc 2002;92(9):479-482.

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3 Responses to Idiopathic toe walking: Insights on intervention

  1. John young says:

    Some very interesting data,I still think afos work better for itw with some fine tuning you can get a good heel stike.

  2. Randall Hall says:

    I have very little if any plantar flexing due to an spinal injury in 1989. I have been searching for many years for some kind of a brace to help me increase plantar flexing. Please let me know if you have any knowledge that may help me. Thank you, Randall Hall

  3. Elaine Andrews says:

    My 7 year old son has just had Botox injections and two lots of casting for periods of two weeks . He now has night splints to wear as we are due to go on holiday to a hot country. He may need more casts and I anticipate physiotherapy will be ongoing. His gait and toe walking is much improved and he can already achieve a heel strike although the tendency is for him to go up on the balls of his feet. He does not appear to have any obvious neurological condition and I have no concerns about any autistic tendencies but I am interested to know what the long term likelihood of his increased flexibility is.

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