Introduction
Idiopathic toe walking (ITW) is an exclusionary gait disorder, where a child presents with a limited or absent heel strike [
1,
2]. ITW is diagnosed when all other conditions known to cause toe walking are eliminated [
1,
2]. ITW is estimated to impact 5% of healthy children at 5 years of age [
3], is present in both sexes [
4] and commonly associated with ankle equinus [
5]. Ankle equinus in any population is thought to be a major contributor to lower limb or foot pain [
6], poor motor skills [
7], and low participation in sports and leisure time physical activities [
8]. Physical activity levels however have not yet been examined in children with ITW [
9].
Physical activity is defined as ‘any bodily movement produced by skeletal muscles that results in energy expenditure’ [
10]. Intensity of physical activity can vary from sedentary, through to light, moderate and vigorous intensities which are defined according to their ratio of a person’s resting energy expenditure [
10]. Physical activity is important for prevention of obesity [
11] and bone health [
12]. A child’s physical activity is influenced by a number of modifiable (psychological, cognitive, emotional, healthy diet) and non-modifiable (gender, male parent weight, previous physical activity engagement) factors [
13]. Australian guidelines provide recommendations for minimum amounts of physical activity at varying intensities for children across different age groups. These movement guidelines are for a minimum of 60 minutes of energetic play, which align with moderate to vigorous physical activity (MVPA) for children above the ages of 3 years. These guidelines also recommend several hours of light physical activity (LPA), limiting sedentary recreational screen time to less than 120 minutes per day and block sleep time designed for different age groupings [
13]. Additional recommendations to maximise the impact of physical activity on health include breaking up long periods of sitting, consistent sleep hygiene and an uninterrupted sleep each night [
14]. Meeting these guidelines are not only important for a child’s health but also for their quality of life and psychological wellbeing [
15,
16].
Physical activity intensity and type (including sedentary behaviour) is commonly measured using accelerometery, owing to its convenience and acceptability compared to the criterion standard of indirect calorimetry (oxygen consumption). Accelerometry has been utilised to assess habitual physical activity in children who toe walk from medical conditions such as cerebral palsy and autism. Studies concluded that children who toe walk with these diagnoses were less likely to meet physical activity guidelines compared to typically developing peers [
17,
18]. To our knowledge, there are no studies examining the physical activity level of children with an ITW gait using accelerometry outside of the laboratory or clinical setting.
There remains controversy as to whether ITW should be treated, or left to self-resolve [
1]. Treatment decisions may be based on many factors such as impairment at the foot or ankle, any pain, or a child’s ability to participate, yet the range of these factors are not commonly reported within treatment studies about ITW [
1]. Developing a greater understanding of any burden of disease associated with this condition could assist health professionals and family navigate the varied treatment options and help inform treatment timing decisions. This study aimed to explore any burden ITW has by describing if children with an ITW gait meet Australian 24-hour movement guidelines, and identifying any factors associated with moderate to vigorous physical activity time. Our hypothesis was that children with ITW would not meet the Australian guidelines.
Discussion
This study investigated the physical activity of children with ITW gait against the Australian 24-hour movement guidelines. Participants within this study achieved sufficient physical activity intensity [
14]. This contrasted with our hypothesis, given many children with gait disorders are less physically active than their peers, and do not meet physical activity recommendations [
28,
29]. Finding physical activity levels in this cohort higher than the minimum recommended levels by the guidelines may provide some insights into the less favourable outcomes of management of children with ITW reported by clinicians [
6] and parents [
30]. Higher levels of physical activity in children with ITW may prompt dosage consideration of any prescribed treatment. For example, children with ITW may need to practice a prescribed new movement more frequently than other children who move less in order to establish new movement patterns. This may be particularly pertinent in older children with ITW who may have more ingrained movement patterns.
Although the children within this study all met the physical activity guidelines for MVPA, they generally spent greater than the recommended time in front of screens, and the majority did not meet the sleep guidelines. Increased screen time [
31] and reduced sleep [
31] are risk factors for obesity within children, although prevalence of high BMI was not greater than in the general population for children in this cohort. To our knowledge, sleep variables have not been collected with ITW cohorts before, therefore comparison of this data to similar populations was not possible. Other children who toe walk with diagnoses such as autism, regularly report difficulties with sleep onset, insomnia and sleep disruption [
32]. Further research may consider investigating these sleep variables in children with ITW. It is commonly accepted that some children with ITW display different sensory behaviours to children without toe walking gait, and altered sleep patterns as well as reduced sleep may exist [
7]. Sleep quality and quantity of children with ITW, particularly where uncomfortable interventions such as serial casting may impact sleep hygiene should be considered as part of treatment planning.
Movement and sensory behaviours have been examined in other studies including children with ITW [
7,
33]. These studies report differing behaviours thought to be related to sensory processing challenges and delays in balance and motor skill acquisition in children with ITW compared to typically developing children [
7,
33]. The differing behaviours included exhibiting greater sensory seeking behaviours or increased movement in play, such as falling, spinning or fidgeting. In this study children with ITW recorded increased movement through accelerometry, and unsolicited parent responses indicated high levels of movement all of the time, in alignment with the increase in movement reported in prior studies. In the future, researchers may consider collecting parent or teacher reported sensory processing information to understand any relationship with the elevated physical activity observed in children with ITW gait.
Psychological, cognitive, and emotional barriers are known to influence physical activity in children [
13]. The present results suggest that the ability of children with ITW to participate with their peers may be associated with their level of moderate to vigorous physical activity. This relationship is similar to that seen between physical activity and social functioning in children with cerebral palsy [
34]. The design of the present study does not permit the establishment of a causal link between physical activity enhancing perceived quality of life related to social functioning. Nevertheless, this association is one that researchers and clinicians should consider when designing and delivering interventions to impact either variable. Clinicians may consider asking children about play, friendships, and how they interact with their peers during play, to understand the impact of ITW gait on quality of life outcomes.
Participants with ITW in this study reported lower quality of life (total PedsQL scale score) within all individual functional domains when compared to healthy peers [
22]. In comparison, parents of children with ITW reported their children to have lower quality of life total score and emotional domain lower score only when compared to healthy peers [
22]. In prior research, children with cerebral palsy scored themselves as having lower physical functioning, but higher scores in all psychosocial domains compared to children with ITW in this study [
35]. In comparison, parents of children with cerebral palsy indicated their child had greater problems in most domains of the PedsQL compared to parents of children with ITW [
35]. Similar to children with ITW in this study, children with cerebral palsy and their parents have discordant HRQoL reports using the PedsQL, endorsing PedsQL instructions that encourage both parent proxy and child self-report to be collected. Parent-Proxy Report PedsQL scale scores of children with autism who may also toe walk were also similar to the Parent-Proxy Report scale scores of children with ITW in this study in all domains except social functioning. Whereas parents of children with autism rated their child as having lower quality of life scores than those with ITW [
36]. Whilst not statistically analysed, the scores taken from Child-Self Report reports of children with ITW in this study appear similar to those reported by children with a range of chronic health conditions [
22]. Clinicians should consider using a similar HRQoL lens when providing care for children with ITW gait as they would with children with cerebral palsy, autism, or chronic health conditions when determining treatment decisions. Future research should also consider determining the minimal clinical important difference.
There are several limitations in this study. Non-dominant wrist worn accelerometer is generally favoured in children’s physical activity studies to increase validity of activity intensity [
37], valid wear-time and adherence [
38]. However, it is unknown if this data collection method may overestimate physical activity. Therefore, results presented should be interpreted with caution until replicated in a study with cut points specifically validated in children with ITW gait. A further limitation is the small sample size, as it was calculated based on power estimates relating to the larger study based on a different outcome measure. This, combined with the missing data resulted in minimising statistical analysis and comparisons to normative populations so not to overemphasise or generalise results to the entire ITW population. Future studies with larger sample sizes should enable in-depth analysis of any association between factors known to impact physical activity levels.
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