RoBétArmé Project: Human-robot collaborative construction system for shotcrete digitization and automation through advanced perception, cognition, mobility and additive manufacturing skills.

The importance of construction automation has grown worldwide, aiming to deliver new machineries for the automation of roads, tunnels, bridges, buildings and earth-work construction. This need is mainly driven by (i) the shortage and rising costs of skilled workers, (ii) the tremendous increased needs for new infrastructures to serve the daily activities and (iii) the immense demand for maintenance of ageing infrastructure. Shotcrete (sprayed concrete) is increasingly becoming popular technology among contractors and builders, as its application is extremely economical and flexible as the growth in construction repairs in developed countries demand excessive automation of concrete placement. Even if shotcrete technology is heavily mechanized, the actual application is still performed manually at a large extend. RoBétArméEuropean project targets the Construction 4.0 transformation of the construction with shotcrete with the adoption of breakthrough technologies such as sensors, augmented reality systems, high-performance computing, additive manufacturing, advanced materials, autonomous robots and simulation systems, technologies that have already been studied and applied so far in Industry 4.0. The paper at hand showcases the development of a novel robotic system with advanced perception, cognition and digitization capabilities for the automation of all phases of shotcrete application. In particular, the challenges and barriers in shotcrete automation are presented and the RoBétArmésuggested solutions are outlined. We introduce a basic conceptual architecture of the system to be developed and we demonstrate the four application scenarios on which the system is designated to operate.

The RoBétArmé European project targets the Construction 4.0 transformation of the construction with shotcrete with the adoption of breakthrough technologies such as sensors, augmented reality systems, high-performance computing, additive manufacturing, advanced materials, autonomous robots and simulation systems, technologies that have already been studied and applied so far in Industry 4.0. This paper showcases a case study on which novel robotic systems will be developed for the automation of shotecrete application. The outcomes of this research can be widely used in other application technologies related to the construction domain.

Behavior adaptation for mobile robots via semantic map compositions of constraint-based controllers.

Specifying and solving Constraint-based Optimization Problems (COP) has become a mainstream technology for advanced motion control of mobile robots. COP programming still requires expert knowledge to transform specific application context into the right configuration of the COP parameters (i.e., objective functions and constraints). The research contribution of this paper is a methodology to couple the context knowledge of application developers to the robot knowledge of control engineers, which, to our knowledge, has not yet been carried out. The former is offered a selected set of symbolic descriptions of the robots' capabilities (its so-called "behavior semantics") that are translated in control actions via "templates" in a "semantic map"; the latter contains the parameters that cover contextual dependencies in an application and robot vendor-independent way. The translation from semantics to control templates takes place in an "interaction layer" that contains 1) generic knowledge about robot motion capabilities (e.g., depending on the kinematic type of the robots), 2) spatial queries to extract relevant COP parameters from a semantic map (e.g., what is the impact of entering different types of "collision areas"), and 3) generic application knowledge (e.g., how the robots' behavior is impacted by priorities, emergency, safety, and prudence). This particular design of, and interplay between, the application, interaction, and control layers provides a structured, conceptually simple approach to advance the complexity of mobile robot applications. Eventually, industry-wide cooperation between representatives of the application and control communities should result in an interaction layer with different standardized versions of semantic complexity.

Dynamic Semantic World Models and Increased Situational Awareness for Highly Automated Inland Waterway Transport.

Automated surface vessels must integrate many tasks and motions at the same time. Moreover, vessels as well as monitoring and control services need to react to physical disturbances, to dynamically allocate software resources available within a particular environment, and to communicate with various other actors in particular navigation and traffic situations. In this work, the responsibility for the situational awareness is given to a mediator that decides how: 1) to assess the impact of the actual physical environment on the quality and performance of the ongoing task executions; 2) to make sure these tasks satisfy the system requirements; and 3) to be robust against disturbances. This paper proposes a set of semantic world models within the context of inland waterway transport, and discusses policies and methodologies to compose, use, and connect these models. Model-conform entities and relations are composed dynamically, that is, corresponding to the opportunities and challenges offered by the actual situation. The semantic world models discussed in this work are divided into two main categories: 1) the semantic description of a vessel's own properties and relationships, called the internal world model, or body model, and 2) the semantic description of its local environment, called the external world model, or map. A range of experiments illustrate the potential of using such models to decide the reactions of the application at runtime. Furthermore, three dynamic, context-dependent, ship domains are integrated in the map as two-dimensional geometric entities around a moving vessel to increase the situational awareness of automated vessels. Their geometric representations depend on the associated relations; for example, with: 1) the motion of the vessel, 2) the actual, desired, or hypothesised tasks, 3) perception sensor information, and 4) other geometries, e.g., features from the Inland Electronic Navigational Charts. The ability to unambiguously understand the environmental context, as well as the motion or position of surrounding entities, allows for resource-efficient and straightforward control decisions. The semantic world models facilitate knowledge sharing between actors, and significantly enhance explainability of the actors' behaviour and control decisions.

Semi-automatic methods for tracking the medial gastrocnemius muscle-tendon junction using ultrasound: a validation study.

NEW FINDINGS: What is the central question of this study? Is the proposed semi-automatic algorithm suitable for tracking the medial gastrocnemius muscle-tendon junction in ultrasound images collected during passive and active conditions? What is the main finding and its importance? The validation of a method allowing efficient tracking of the muscle-tendon junction in both passive and active conditions, in healthy as well as in pathological conditions. This method was tested in common acquisition conditions and the developed software made freely available. ABSTRACT: Clinically relevant information can be extracted from ultrasound (US) images by tracking the displacement of the junction between muscle and tendon. This paper validated automatic methods for tracking the location of muscle-tendon junction (MTJ) between the medial gastrocnemius and the Achilles tendon during passive slow and fast stretches, and active ankle rotations while walking on a treadmill. First, an automatic algorithm based on an optical flow approach was applied on collected US images. Second, results of the automatic algorithm were evaluated and corrected using a quality measure that indicated which critical images need to be manually corrected. US images from 12 typically developed (TD) children, 12 children with spastic cerebral palsy (SCP) and eight healthy adults were analysed. Automatic and semi-automatic tracking methods were compared to manual tracking using root mean square errors (RMSE). For the automatic tracking, RMSE was less than 3.1 mm for the slow stretch and 5.2 mm for the fast stretch, the worst case being for SCP. The tracking results in the fast stretch condition were improved (especially in SCP) by using the semi-automatic approach, with an RMSE reduction of about 30%. During walking, the semi-automatic method also reduced errors, with a final RMSE of 3.6 mm. In all cases, data processing was considerably shorter using the semi-automatic method (2 min) compared to manual tracking (20 min). A quick manual correction considerably improves tracking of the MTJ during gait and allows to achieve results suitable for further analyses. The proposed algorithm is freely available.

Efficient image based method using water-filled balloons for improving probe spatial calibration in 3D freehand ultrasonography.

The ultrasound (US) probe spatial calibration is a key prerequisite for enabling the use of the 3D freehand US technique. Several methods have been proposed for achieving an accurate and precise calibration, although these methods still require specialised equipment. This equipment is often not available in research or clinical facilities. Therefore, the present investigation aimed to propose an efficient US probe calibration method that is accessible in terms of cost, easy to apply and capable of achieving results suitable for clinical applications. The data acquisition was carried out by performing two perpendicular US sweeps over water filled balloon phantoms. The data analysis was carried out by computing the similarity measures between 2D images from the first sweep and the corresponding images of the 3D reconstruction of the second sweep. These measures were maximized by using the Nelder-Mead algorithm, to find the optimal solution for the calibration parameters. The calibration results were evaluated in terms of accuracy and precision by comparing known phantom geometries with those extracted from the US images. The accuracy and the precision after applying the calibration method were improved. By using the parameters obtained from the plane phantom method as initialization of the calibration parameters, the accuracy and the precision in the best scenario was 0.4 mm and 1.5 mm, respectively. These results were in line with the methods requiring specialised equipment. However, the applied method was unable to consistently produce this level of accuracy and precision. The calibration parameters were also tested in a musculoskeletal application, revealing sufficient matching of the relevant anatomical features when multiple US sweeps are combined in a 3D reconstruction. To improve the current results and increase the reproducibility of this research, the developed software is made available.

Medial Gastrocnemius Muscle-Tendon Junction and Fascicle Lengthening across the Range of Motion Analyzed in 2-D and 3-D Ultrasound Images.

Ultrasound imaging modalities offer a clinically viable method to visualize musculoskeletal structures. However, proper data comparison between investigations is compromised because of a lack of measurement error documentation and method standardization. This investigation analyzes the reliability and validity of extracting medial gastrocnemius belly and fascicle lengths and pennation angles in different ankle joint positions, across the full range of motion, in a cohort of 11 children with spastic cerebral palsy and 11 typically developed children. Each of these parameters was extracted from two consecutive acquisitions, using both 2-D and 3-D ultrasound images. The findings suggest that the muscle tendon junction extraction in 2-D images can be a suitable parameter for analyzing medial gastrocnemius muscle length in typically developed children and children with spastic cerebral palsy, although averaging over multiple measurements is recommended to reduce variability. More caution should be taken when performing analyses based on fascicle length.

An innovative solution to reduce muscle deformation during ultrasonography data collection.

BACKGROUND: 3D freehand ultrasound enables the creation of volumetric data. The acquisition of morphological features, such as muscle volume, is influenced by the variations in force applied to the skin with the ultrasound probe. To minimise the deformations, a concave-shaped plastic mount combined with a custom-shaped gel pad was developed for the ultrasound head, named Portico. This study analyses to what extent the Portico reduces muscle deformation and corresponding errors in estimating muscle volume. METHOD: Twenty medial gastrocnemius (MG) muscles were assessed (10 from typically developing children; 10 from children with spastic cerebral palsy). Two repetitions were acquired in each of the following approaches: (1) with the lower leg submerged in a water tank as a non-deformed reference; (2) probe-on-skin (PoS) as the conventional approach and (3) the newly introduced Portico. PoS and Portico data were registered with respect to the ones corresponding in a water tank. An in-house software package (Py3DFreeHandUS) was used to process the data and MG volume was estimated using MeVisLab. The minimal detectable change (MDC) was calculated. RESULTS: With respect to the PoS approach, the Portico reduced muscle deformation by 46%. For both the typically developing and spastic cerebral palsy cohorts, lower MDCs were found when using the Portico. DISCUSSION: Despite the improvements, the Portico did not yield statistically more reliable MG volume estimations than the traditional PoS approach. Further improvement can be attained by optimising the fit between the gel pad and the curvature of the limb, using a larger choice of Portico geometries.

Reliability of a clinical 3D freehand ultrasound technique: Analyses on healthy and pathological muscles.

BACKGROUND AND OBJECTIVE: 3D freehand Ultrasonography is a medical imaging technique that can be used to measure muscle and tendon morphological and structural properties, including volume, lengths and echo-intensity. These properties are clinically relevant in neurological disorders such as spastic cerebral palsy to monitor disease progression and evaluate the effect of treatment. This study presents a methodology for extracting these parameters along with a clinical reliability analysis for the data acquisition and processing. METHODS: The medial gastrocnemius muscles and Achilles tendon of 10 typically developing children and 10 children with spastic cerebral palsy were assessed. An open-source in-house software library developed in Python (Py3DFreeHandUS) was used to reconstruct, into one 3D data set, the data simultaneously acquired from an US machine and a motion tracking system. US images were manually segmented and linearly interpolated by means of a new simplified approach which involved sequentially decreasing the total number of images used for muscle border segmentation from 100% to 5%. Acquisition and processing reliability was defined based on repeated measures from different data processers and from different data acquirers, respectively. RESULTS: When only 10% of the US images were outlined, there was an average underestimation of muscle volume of 1.1% and 1.6% with respect the computation of all the available images, for the typically developing and spastic cerebral palsy groups, respectively. For both groups, the reliability was higher for data processing than for data acquisition. High inter-class correlation coefficient values were found for processing and acquisition reliability, with worst case values of 0.89 and 0.61, respectively. The standard error of measurement, expressed as a percentage of the average volumes, was smaller than 2.6 ml (4.8%) in all cases. CONCLUSIONS: The present analysis demonstrates the effectiveness of applying 3D freehand ultrasonography in a clinical setting for analysing healthy and pathological paediatric muscle.

Can in Vivo Medial Gastrocnemius Muscle-Tendon Unit Lengths be Reliably Estimated by Two Ultrasonography Methods? A Within-Session Analysis.

A clinically feasible method to reliably estimate muscle-tendon unit (MTU) lengths could provide essential diagnostic and treatment planning information. A 3-D freehand ultrasound (3-DfUS) method was previously validated for extracting in vivo medial gastrocnemius (MG) lengths, although the processing time can be considered substantial for the clinical environment. This investigation analyzed a quicker and simpler method using the US transducer as a spatial pointer (US-PaP), where the within-session reliability of extracting the muscle-tendon unit (MTU) and tendon lengths are estimated. MG MTU lengths were extracted in a group of 14 healthy adults using both 3-DfUS and US-PaP. Two consecutive acquisitions were performed per participant, and the data processed by two researchers independently. The intra-class correlation coefficients were above 0.97, and the standard error of measurements below 3.6 mm (1.5%). This investigation proposes that the simplified US-PaP method is a viable alternative for estimating MG MTU lengths.

The reliability and validity of a clinical 3D freehand ultrasound system.

BACKGROUND AND OBJECTIVE: Acquiring large anatomical volumes in a feasible manner is useful for clinical decision-making. A relatively new technique called 3D freehand ultrasonography is capable of this by combining a conventional 2D ultrasonography system. Currently, a thorough analysis of this technique is lacking, as the analyses are dependent on the software implementation details and the choice of measurement systems. Therefore this study starts by making this implementation available under the form of an open-source software library to perform 3D freehand ultrasonography. Following that, reliability and validity analyses of extracting volumes and lengths will be carried out using two independent motion-tracking systems. METHODS: A PC-based ultrasonography device and two optical motion-tracking systems were used for data acquisition. An in-house software library called Py3DFreeHandUS was developed to reconstruct (off-line) the corresponding data into one 3D data set. Reliability and validity analyses of the entire experimental set-up were performed by estimating the volumes and lengths of ground truth objects. Ten water-filled balloons and six cross-wires were used. Repeat measurements were also performed by two experienced operators. RESULTS: The software library Py3DFreeHandUS is available online, along with the relevant documentation. The reliability analyses showed high intra- and inter-operator intra-class correlation coefficient results for both volumes and lengths. The accuracy analysis revealed a discrepancy in all cases of around 3%, which corresponded to 3 ml and 1 mm for volume and length measurements, respectively. Similar results were found for both of the motion-tracking systems. CONCLUSIONS: The undertaken analyses for estimating volume and lengths acquired with 3D freehand ultrasonography demonstrated reliable design measurements and suitable performance for applications that do not require sub-mm and -ml accuracy.

A Novel Method of Quantifying Gait Deviations Using Plantar Pressure Patterns.

BACKGROUND: Comparing the dynamic pedobarographic patterns of individuals is common practice in basic and applied research. However, this process is often time-consuming and complex, and commercially available software often lacks powerful visualization and interpretation tools. METHODS: We propose a simple method for displaying pixel-level pedobarographic deviations over time relative to a so-called reference pedobarographic pattern. This novel method contains four distinct automated preprocessing stages: 1) normalization of pedobarographic fields (for foot length and width), 2) temporal normalization, 3) a pixel-level z-score-based calculation, and 4) color coding of the normalized pedobarographic fields. Group and patient-level comparisons were illustrated using an experimental data set including diabetic and nondiabetic patients. RESULTS: The automated procedure was found to be robust and quantified distinct temporal deviations in pedobarographic fields. CONCLUSIONS: The advantages of the novel method cover several domains, including visualization, interpretation, and education.

Efficacy measures associated to a plantar pressure based classification system in diabetic foot medicine.

AIMS: The concept of 'classification' has, similar to many other diseases, been found to be fundamental in the field of diabetic medicine. In the current study, we aimed at determining efficacy measures of a recently published plantar pressure based classification system. METHODS: Technical efficacy of the classification system was investigated by applying a high resolution, pixel-level analysis on the normalized plantar pressure pedobarographic fields of the original experimental dataset consisting of 97 patients with diabetes and 33 persons without diabetes. Clinical efficacy was assessed by considering the occurence of foot ulcers at the plantar aspect of the forefoot in this dataset. Classification efficacy was assessed by determining the classification recognition rate as well as its sensitivity and specificity using cross-validation subsets of the experimental dataset together with a novel cohort of 12 patients with diabetes. RESULTS: Pixel-level comparison of the four groups associated to the classification system highlighted distinct regional differences. Retrospective analysis showed the occurence of eleven foot ulcers in the experimental dataset since their gait analysis. Eight out of the eleven ulcers developed in a region of the foot which had the highest forces. Overall classification recognition rate exceeded 90% for all cross-validation subsets. Sensitivity and specificity of the four groups associated to the classification system exceeded respectively the 0.7 and 0.8 level in all cross-validation subsets. CONCLUSIONS: The results of the current study support the use of the novel plantar pressure based classification system in diabetic foot medicine. It may particularly serve in communication, diagnosis and clinical decision making.

Children with Spastic Cerebral Palsy Experience Difficulties Adjusting Their Gait Pattern to Weight Added to the Waist, While Typically Developing Children Do Not.

The prevalence of childhood overweight and obesity is increasing in the last decades, also in children with Cerebral Palsy (CP). Even though it has been established that an increase in weight can have important negative effects on gait in healthy adults and children, it has not been investigated what the effect is of an increase in body weight on the characteristics of gait in children with CP. In CP, pre and post three-dimensional gait analyses are performed to assess the effectiveness of an intervention. As a considerable amount of time can elapse between these measurements, and the effect of an alteration in the body weight is not taken into consideration, this effect of increased body weight is of specific importance. Thirty children with the predominantly spastic type of CP and 15 typically developing (TD) children were enrolled (age 3-15 years). All children underwent three-dimensional gait analysis with weight-free (baseline) and weighted (10% of the body weight added around their waist) trials. Numerous gait parameters showed a different response to the added weight for TD and CP children. TD children increased walking velocity, step- and stride length, and decreased double support duration with a slightly earlier timing of foot-off, while the opposite was found in CP. Similarly, increased ranges of motion at the pelvis (coronal plane) and hip (all planes), higher joint angular velocities at the hip and ankle, as well as increased moments and powers at the hip, knee and ankle were observed for TD children, while CP children did not change or even showed decreases in the respective measures in response to walking with added weight. Further, while TD children increased their gastrocnemius EMG amplitude during weighted walking, CP children slightly decreased their gastrocnemius EMG amplitude. As such, an increase in weight has a significant effect on the gait pattern in CP children. Clinical gait analysts should therefore take into account the negative effects of increased weight during pre-post measurements to avoid misinterpretation of treatment results. Overweight and obesity in CP should be counteracted or prevented as the increased weight has detrimental effects on the gait pattern.

A color-code based method for the interpretation of plantar pressure measurements in clinical gait analysis.

Comparing plantar pressure measurements (PPM) of a patient following an intervention or between a reference group and a patient-group is common practice in clinical gait analysis. However, this process is often time consuming and complex, and commercially available software often lacks powerful visualization and interpretation tools. In this paper, we propose a simple method for displaying pixel-level PPM deviations relative to a so-called reference PPM pattern. The novel method contains 3 distinct stages: (1) a normalization of pedobarographic fields (for foot length and width), (2) a pixel-level z-score based calculation and, (3) color coding of the normalized pedobarographic fields. The methodological steps associated to this novel method are precisely described and clinical output illustrated. We believe that the advantages of the novel method cover several domains. The strongest advantage of the novel method is that it provides a straightforward visual interpretation of PPM without decreasing the resolution perspective. A second advantage is that it may guide the selection of a local mapping technique (data reduction technique). Finally, it may be easily used as education tool during the therapist-patient interaction.

Augmented switching linear dynamical system model for gas concentration estimation with MOX sensors in an open sampling system.

In this paper, we introduce a Bayesian time series model approach for gas concentration estimation using Metal Oxide (MOX) sensors in Open Sampling System (OSS). Our approach focuses on the compensation of the slow response of MOX sensors, while concurrently solving the problem of estimating the gas concentration in OSS. The proposed Augmented Switching Linear System model allows to include all the sources of uncertainty arising at each step of the problem in a single coherent probabilistic formulation. In particular, the problem of detecting on-line the current sensor dynamical regime and estimating the underlying gas concentration under environmental disturbances and noisy measurements is formulated and solved as a statistical inference problem. Our model improves, with respect to the state of the art, where system modeling approaches have been already introduced, but only provided an indirect relative measures proportional to the gas concentration and the problem of modeling uncertainty was ignored. Our approach is validated experimentally and the performances in terms of speed of and quality of the gas concentration estimation are compared with the ones obtained using a photo-ionization detector.

A novel device for standardizing marker placement at the calcaneus.

BACKGROUND: The determination of anatomical reference frames in the rearfoot during three-dimensional multisegment foot modeling has been hindered by a variety of factors. One of these factors is related to the difficulty in palpating, or the absence of, anatomical landmarks. A novel device (the Calcaneal Marker Device) aimed at standardizing marker placement at the calcaneus was, therefore, developed and evaluated for its reliability. METHODS: Throughout a random repeated-measures design, the repeatability of calcaneal marker placement was evaluated for two techniques: manual placement and placement using the Calcaneal Marker Device. Translational changes after marker placement and the clinical effect on intersegment angle calculation were quantified. RESULTS: Intraobserver variability was greater in therapist 2 (<5.3 mm) compared with therapist 1 (<2.9 mm). Intraobserver variability was also found to be less than 1.6 mm throughout use of the device. Interobserver variability was found to be significantly higher for the position of markers placed manually (5.8 mm), whereas with the Calcaneal Marker Device, the variability remained lower (<1.3 mm). The effect on the computed intersegment angles followed a similar trend, with variability of 0.4° to 4.0° and 1.0° to 8.7° for CMD and manual placement, respectively. CONCLUSIONS: These findings suggest that variations in marker placement are considerably reduced when the novel Calcaneal Marker Device is used, possibly toward the limits dictated by the fine motor skills of therapists and tissue artifacts.

Classification of forefoot plantar pressure distribution in persons with diabetes: a novel perspective for the mechanical management of diabetic foot?

BACKGROUND: The aim of this study was to identify groups of subjects with similar patterns of forefoot loading and verify if specific groups of patients with diabetes could be isolated from non-diabetics. METHODOLOGY/PRINCIPAL FINDINGS: Ninety-seven patients with diabetes and 33 control participants between 45 and 70 years were prospectively recruited in two Belgian Diabetic Foot Clinics. Barefoot plantar pressure measurements were recorded and subsequently analysed using a semi-automatic total mapping technique. Kmeans cluster analysis was applied on relative regional impulses of six forefoot segments in order to pursue a classification for the control group separately, the diabetic group separately and both groups together. Cluster analysis led to identification of three distinct groups when considering only the control group. For the diabetic group, and the computation considering both groups together, four distinct groups were isolated. Compared to the cluster analysis of the control group an additional forefoot loading pattern was identified. This group comprised diabetic feet only. The relevance of the reported clusters was supported by ANOVA statistics indicating significant differences between different regions of interest and different clusters. CONCLUSION/S SIGNIFICANCE: There seems to emerge a new era in diabetic foot medicine which embraces the classification of diabetic patients according to their biomechanical profile. Classification of the plantar pressure distribution has the potential to provide a means to determine mechanical interventions for the prevention and/or treatment of the diabetic foot.

Pattern description and reliability parameters of six force-time related indices measured with plantar pressure measurements.

BACKGROUND: Functional interpretation of plantar pressure measurements is commonly done through the use of ratios and indices which are preceded by the strategic combination of a subsampling method and selection of physical quantities. However, errors which may arise throughout the determination of these temporal indices/ratio calculations (T-IRC) have not been quantified. The purpose of the current study was therefore to estimate the reliability of T-IRC following semi-automatic total mapping (SATM). METHODS: Using a repeated-measures design, two experienced therapists performed three subsampling sessions on three left and right pedobarographic footprints of ten healthy participants. Following the subsampling, six T-IRC were calculated: Rearfoot-Forefoot_fti, Rearfoot-Midfoot_fti, Forefoot medial/lateral_fti, First ray_fti, Metatarsal 1-Metatarsal 5_fti, Foot medial-lateral_fti. FINDINGS: Patterns of the T-IRC were found to be consistent and in good agreement with corresponding knowledge from the literature. The inter-session errors of both therapists were similar in pattern and magnitude. The lowest peak inter-therapist error was found in the First ray_fti (6.5 a.u.) whereas the highest peak inter-therapist error was observed in the Forefoot medial/lateral_fti (27.0 a.u.) The magnitude of the inter-session and inter-therapist error varied over time, precluding the calculation of a simple numerical value for the error. The difference between both error parameters of all T-IRC was negligible which underscores the repeatability of the SATM protocol. CONCLUSION: The current study reports consistent patterns for six T-IRC and similar inter-session and inter-therapist error. The proposed SATM protocol and the T-IRC may therefore serve as basis for functional interpretation of footprint data.

Repeatability of a 3D multi-segment foot model protocol in presence of foot deformities.

Repeatability studies on 3D multi-segment foot models (3DMFMs) have mainly considered healthy participants which contrasts with the widespread application of these models to evaluate foot pathologies. The current study aimed at establishing the repeatability of the 3DMFM described by Leardini et al. in presence of foot deformities. Foot kinematics of eight adult participants were analyzed using a repeated-measures design including two therapists with different levels of experience. The inter-trial variability was higher compared to the kinematics of healthy subjects. Consideration of relative angles resulted in the lowest inter-session variability. The absolute 3D rotations between the Sha-Cal and Cal-Met seem to have the lowest variability in both therapists. A general trend towards higher σ(sess)/σ(trial) ratios was observed when the midfoot was involved. The current study indicates that not only relative 3D rotations and planar angles can be measured consistently in patients, also a number of absolute parameters can be consistently measured serving as basis for the decision making process.

Repeatability in the assessment of multi-segment foot kinematics.

A recently published systematic review on 3D multi-segment foot models has illustrated the lack of repeatability studies providing evidence for appropriate clinical decision making. The aim of the current study was to assess the repeatability of the recently published model developed by Leardini et al. [10]. Foot kinematics of six healthy adults were analyzed through a repeated-measures design including two therapists with different levels of experience and four test sessions. For the majority of the parameters moderate or good repeatability was observed for the within-day and between-day sessions. A trend towards consistently higher within- and between-day variability was observed for the junior compared to the senior clinician. The mean inter-session variability of the relative 3D rotations ranged between 0.9-4.2° and 1.6-5.0° for respectively the senior and junior clinician whereas for the absolute angles this variability increased to respectively 2.0-6.2° and 2.6-7.8°. Mean inter-therapist standard deviations ranged between 2.2° and 6.5° for the relative 3D rotations and between 2.8° and 7.6° for the absolute 3D rotations. The ratio of inter-therapist to inter-trial errors ranged between 1.8 and 5.5 for the relative 3D rotations and between 2.4 and 9.7 for the absolute 3D rotations. Absolute angle representation of the planar angles was found to be more difficult. Observations from the current study indicate that an adequate normative database can be installed in gait laboratories, however, it should be stressed that experience of therapists is important and gait laboratories should therefore be encouraged to put effort in training their clinicians.