NGS-Panel Diagnosis Developed for the Differential Diagnosis of Idiopathic Toe Walking and Its Application for the Investigation of Possible Genetic Causes for the Gait Anomaly.

Idiopathic toe walking (ITW) describes a condition affecting approximately 4.5% of children. Toe walking is an accompanying symptom for many hereditary disorders. This retrospective study uses next-generation sequencing-panel-diagnosis to investigate the feasibility of genetic testing to research the possible genetic causes of ITW and for differential diagnosis. Data were taken from our inhouse database, the minimum age for participants was 3 years. Underlying neurological or orthopaedic conditions were tested for and ruled out prior to diagnosing ITW. Patients, who experienced complications before, during or immediately after birth, children with autism, and patients toe walking less than 50% of the time were excluded. Eighty-nine patients were included in the study, in which 66 (74.2%) patients were boys and 23 (25.8%) girls. Mean age at testing was 7.7 years (range: 3-17 years). Fifteen of the 89 patients included in the study (16.9%) had a genetic variant identified as likely pathogenic or pathogenic by the genetics laboratory. Additionally, we found 129 variants of uncertain significance. About 65.2% of patients showed a pes cavus foot deformity, 27% of patients reportedly had at least one relative who also displayed the gait anomaly, and 37.1% had problems with their speech development. Despite the limitations of the sample size and the scope of our genetic testing targets, our results indicate that research into the genetic causes of ITW could better our understanding of the causes of ITW in otherwise healthy children, to help develop novel methods to detect serious conditions early. ITW could be an early onset symptom for further hereditary conditions.

Ankle Kinematics Characterization in Children with Idiopathic Toe Walking: Does the Foot Model Change the Clinical Evaluation?

Idiopathic toe walking (ITW) is a gait deviation characterized by forefoot contact with the ground, sometimes observed in children, that alters ankle kinematics, possibly leading to health-related issues. When studying foot and ankle gait deviations, the adoption of a single-segment foot model entails a significant simplification of foot and ankle movement, and thus may potentially mask some important foot dynamics. Differences in ankle kinematics between single- (conventional gait model, PiG, or Davis) and multi-segment (Oxford foot model, OFM) foot models were investigated in children with ITW. Fourteen participants were enrolled in the study and underwent instrumented gait analysis. Children were asked to walk barefoot and while wearing a foot orthosis that modified the ankle movement pattern toward a more physiological one without blocking foot intrinsic motion. ITW gait abnormalities, e.g., the absence of heel rocker and the presence of anticipated forefoot rocker, were found/not found according to the foot model. Walking conditions significantly interacted with the foot model effect. Finally, the different characterization of gait abnormalities led to a different classification of ITW, with a possible impact on the clinical evaluation. Due to its closer adhesion to ankle anatomy and to its sensitivity to ITW peculiarities, OFM may be preferable for instrumented gait analysis in this population.

Impact of Gait Events Identification through Wearable Inertial Sensors on Clinical Gait Analysis of Children with Idiopathic Toe Walking.

Idiopathic toe walking (ITW) is a gait deviation characterized by forefoot contact with the ground and excessive ankle plantarflexion over the entire gait cycle observed in otherwise-typical developing children. The clinical evaluation of ITW is usually performed using optoelectronic systems analyzing the sagittal component of ankle kinematics and kinetics. However, in standardized laboratory contexts, these children can adopt a typical walking pattern instead of a toe walk, thus hindering the laboratory-based clinical evaluation. With these premises, measuring gait in a more ecological environment may be crucial in this population. As a first step towards adopting wearable clinical protocols embedding magneto-inertial sensors and pressure insoles, this study analyzed the performance of three algorithms for gait events identification based on shank and/or foot sensors. Foot strike and foot off were estimated from gait measurements taken from children with ITW walking barefoot and while wearing a foot orthosis. Although no single algorithm stands out as best from all perspectives, preferable algorithms were devised for event identification, temporal parameters estimate and heel and forefoot rocker identification, depending on the barefoot/shoed condition. Errors more often led to an erroneous characterization of the heel rocker, especially in shoed condition. The ITW gait specificity may cause errors in the identification of the foot strike which, in turn, influences the characterization of the heel rocker and, therefore, of the pathologic ITW behavior.

Effects of wearing a foot orthosis on ankle function in children with idiopathic toe walking during gait.

Background: Idiopathic toe walking (ITW) is a gait deviation characterized by forefoot contact with the ground, possibly enhancing the risk of falling and causing Achilles' tendon shortening and psychological discomfort. Between possible treatments, foot orthosis may limit ITW when worn. With these premises, the effects of a novel foot orthosis (A.Dyn.O.®) on ankle function were analyzed in children with ITW during gait. Methods: Twenty-one children were recruited in the study after ITW diagnosis. At follow-up assessment after a habituation period of at least two weeks, participants walked in barefoot condition and while wearing A.Dyn.O.®. Kinetics and kinematics were derived from a multi-segment foot model using an optoelectronic system. Gait spatiotemporal parameters, ankle kinetic and kinematic and rockers timing were analyzed. Lastly, ITW severity was classified according to Alvarez classification. Differences between conditions were verified with paired t-test. Statistical parametric mapping was used to evaluate differences in the entire kinematic and kinetic waveforms. Findings: Wearing A.Dyn.O.®, step cadence was reduced, step length, stance phase and stride duration increased; physiological heel rocker was present, thus postponing the timing of ankle and forefoot rockers; ankle dorsiflexion angular excursion, range of motion, maximal dorsiflexor and plantarflexor moments together with maximal power absorption and production were all amplified. Interpretation: While wearing it, A.Dyn.O.® limited gait deviations typical of ITW and improved ITW severity classification for most of the participants. These findings suggest that the use of A.Dyn.O.® may assist ITW treatment, preventing children from toe walking and thus limiting its side effects.

Adherence to serial casting protocols for idiopathic toe walking: A quality improvement initiative.

PURPOSE: This initiative aimed to assess adherence to Scottish Rite for Children's serial casting protocol for children with idiopathic toe walking (ITW), factors related to adherence, and outcomes after education regarding the protocol. METHODS: 60 patients aged 7.1±2.7 years who completed serial casting were examined at baseline phase (n = 30) and post-education phase (n = 30). Protocols include weekly serial casting for 4 to 6 weeks to achieve 10° of ankle dorsiflexion (ADF) passive range of motion (PROM) with knees extended (KE), assessing the foot posture index (FPI-6) and single leg stance (SLS). Baseline phase evaluated adherence to protocols. Education phase evaluated factors related to adherence and education regarding serial casting findings. Post-education phase evaluated the impact of the education phase. RESULTS: Serial casting averaged 4.8±1.5 weeks (n = 60). ADF PROM was measured with 100% adherence. ADF PROM KE averaged -10.7° pre-cast and significantly improved to +6.5° post-cast (n = 60), and it significantly improved post-cast post-education (p = 0.04). FPI-6 and SLS adherence significantly improved post-cast post-education. FPI-6 total score averaged +5.3 at baseline and +5.8 post-cast (n = 35). CONCLUSION: Education of staff in serial casting protocols improved adherence and patient outcomes. Patients with ITW and ADF PROM KE -10° benefit from serial casting to improve PROM and to allow for orthotic use post-casting.

Serial ankle casts for patients with idiopathic toe walking: effects on functional gait parameters.

PURPOSE: The aim of the present study was to investigate the functional effects on gait parameters of serial ankle casts for patients with idiopathic toe walking (ITW), in comparison with an unremarkable control group. METHODS: A prospective trial with a pre-test-post-test control group design included ten patients with ITW and ten healthy matched children. Children with ITW underwent serial casting to stretch the plantar flexors, with two 14-day periods with walking plaster casts set at the maximum available ankle dorsiflexion. Both groups were assessed clinically and using a functional gait analysis before and after serial casting, as well as at a six-month follow-up visit. RESULTS: The normalized plantar heel force increased from 5% pre-interventionally to 79% at the follow-up. The upper ankle-joint angle and the base angle also demonstrated significant changes. Normalized compound action potentials of the medial heads of the gastrocnemius were reduced by 70%. None of these parameters demonstrated any significant differences at the follow-up examination in comparison with the healthy control group. Variations in the displacement of the knee joint on the sagittal plane and of the center of gravity in the transverse plane did not show any significant differences in comparison with the control group. CONCLUSION: The reduction of muscle tone and lengthening of the ankle plantar flexors led to persistent increased active ankle dorsiflexion with significant long-term improvement of functional kinematic parameters. No significant difference in the gait analysis was found between the ITW group and healthy children six months after treatment.Level of Evidence: Level II - Therapeutic.

WEARABLE SENSOR-BASED GAIT CLASSIFICATION IN IDIOPATHIC TOE WALKING ADOLESCENTS.

Idiopathic toe walking on the balls of the feet is commonly found in children. Many toddlers who are just beginning to walk show signs of toe walking, but when toe walking persists after two years of age, the child's risk of falling increases as well as the risk of other developmental delays. Idiopathic toe-walking is estimated to occur in 7 to 24% of children. In order to address the problem of toe walking and assess improvements due to intervention, one needs to identify heel-toe gait versus toe-toe gait in natural environments of idiopathic toe walkers. The aim of this study was to investigate if learning algorithms utilizing triaxial accelerometers and gyroscopes from wearable sensors could detect and differentiate heel-toe gait versus toe-toe gait. In this study, 5 adolescents (13± 5 years) patients with idiopathic toe walking characteristics wore inertial sensor at L5 - S1 joint. New interventions can be designed for idiopathic toe walking population, but currently, it is a challenge to quantify the efficiency of toe-walking intervention. In recent times, with the advancement of machine learning classification methods and powerful computing, longitudinal data from wearable sensors can be used to accurately classify gait abnormalities. The aim of this study was to investigate machine learning methods to classify toe-toe walking versus heel-toe walking using data from a single inertial sensor. We found that k-means clustering was successful in differentiating toe walking with that of typical walking signals. We found that some of the linear variability based features such as standard deviation, Root Mean Square (RMS), and kurtosis contained most of the variability among the data and could therefore distinguish toe-toe gait versus heeltoe gait through clustering. The k-means cluster provided an 82% accuracy score with a specificity of 83% and sensitivity of 86%. We further utilized Recurrent Convolution Neural Network (RNN) such as Long Short-Term Memory (LSTM). The LSTM model was another classification method that was used to distinguish between toe-toe gait and heel-toe gait. Wearable sensors integrated with machine and deep learning algorithms have the capability to transform current on-going therapy methods and monitor patients longitudinally for their improvement in gait. These novel learning-based techniques could successfully classify toe walking gait and help in estimating the efficacy of the treatment in idiopathic toe walking adolescents.