Andrea Ancillao

An optoelectronic based approach for handwriting capture

Clinical practice for the evaluation of motor and cognitive capabilities often relies upon writing and drawing tests. A non-invasive method to capture handwriting and analyze data is therefore needed. In this work a method to capture motion of a pen through a mo-cap optoelectronic system was developed, which could solve the limits of systems based on graphic tablets. Four IR passive markers were placed on a pen cap. Once a pen was equipped with the cap, track of tip was computed through a numeric algorithm using the 3D coordinates of markers provided by the optoelectronic system. Some tests were performed to estimate the error in track reconstruction and to compare the new protocol with previous reconstruction methods. The results showed a higher accuracy of the new method. The new protocol also overcomes the problems related to pen grasping and marker covering that affected other methods described in the literature and permits the evaluation of writing and drawing kinematics as well as postural behaviour related to them.

Neuromuscular taping for the upper limb in Cerebral Palsy: A case study in a patient with hemiplegia

Abstract Objective: To assess quantitatively the effects of Neuromuscular Taping (NMT) on the upper limb in a female child with left hemiplegia, due to Cerebral Palsy (CP). Methods: The patient underwent NMT on cervical level, shoulder and hand only of the plegic upper limb, followed by physical therapy. Kinematic data of upper limbs during reaching task were collected before (PRE) and after 2 weeks of treatment (POST). Results: After the intervention, the affected limb improved in terms of movement duration, Average Jerk and Number of Unit Movements indices, indicating a faster, smoother and less segmented movement. Improvements appeared at the ranges of motion of the upper limb joints, both at shoulder and elbow joints. No significant changes were globally displayed for the unaffected arm. Conclusion: NMT seems to be a promising intervention for improving upper limb movement in patients with CP. Further investigations are certainly needed to assess effectively the effects of the intervention in this pathological state.

Motor strategies and motor programs during an arm tapping task in adults with Down Syndrome

Slow movements and atypical patterns of muscle activation are well-known features of Down Syndrome (DS). Some studies attribute these features to a deficit in voluntary motor commands and preprogramming of actions, that lead subjects with DS to be more reliant on feedback control. In the present study, we evaluated the movement strategies of 13 adult subjects with DS and of 22 age-matched controls (N) during an arm tapping task. By means of quantitative motion analysis, our aim was to describe movement differences in DS respect to typical population and provide a means of interpreting such differences in terms of the underlying different control processes. The results highlighted distinct motor strategies for the tapping task in the two groups, with DS relying more on the trunk motion and N relying on the elbow motion to accomplish the task. Furthermore, DS corrected their wrist trajectory more than N subjects, giving shape to multi-peaked velocity profiles. Longer duration of the trials and a higher index of curvature were found in DS. The results suggest that subjects with DS rely more on feedback control, whereas they have problems with movement planning and feed-forward control. The different strategy operated by subjects with DS leads to a different task performance.

The effects of neuromuscular taping on gait walking strategy in a patient with joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type

Objective: In this case study, biomechanical alterations induced by neuromuscular taping (NMT) were quantified, during walking, in a patient with joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type (JHS/EDS-HT). Methods: A female JHS/EDS-HT patient underwent NMT applications over the low back spine and bilaterally to the knee. Quantitative gait analyses were collected before the NMT application and at the end of the treatment (2 weeks after the first application of NMT). Results: At the end of treatment following the NMT application, left step length showed improvements in cadence and velocity, the left knee showed a reduction in its flexed position at initial contact, and the right ankle joint improved its position at initial contact and in the swing phase. Improvements were also found in kinetics, in terms of the ankle moment and power. Conclusions: Results show that NMT seems to be a promising low-cost intervention for improving gait strategy in patients with JHS/EDS-HT. Further investigations are needed to assess the effects of this treatment intervention on pathological symptoms.

Finite element analysis of the stress state produced by an orthodontic skeletal anchorage system based on miniscrews

Aims: The aim of this work is to produce detailed analysis and quantitative results of the stress state induced in an inferior first molar tooth by an orthodontic mesialization system based on a mini-screw, a bracket, and a rubber elastic string. Materials and Methods: The implant was modeled as a non-osteointegrated Ti-6Al-4V standard mini-screw, implanted in the anterior-buccal region of human jaw. 3D realistic models were constructed using data based on micro-computed tomography scans of human teeth as found in the literature. A couple of self-balanced forces of 4 N was applied and finite element method analysis was run and produced an approximate solution, which allowed to display stress distribution over the whole model. Materials′ behavior was assumed elastic and linear. This approximation applies to the 1 st stage of the orthodontic treatments. Results: A detailed qualitative and quantitative analysis of the stress state is presented through images. Results in terms of stresses and displacements were studied to exclude any possibility of bracket debonding, bone failure, and loss of stability of the screw. Results were compared to the ultimate strengths of the bio-materials involved using engineering failure criteria. The actual stress state was found to be lower than the critical values. Conclusion: Results allows to qualitatively see the amount of bone, surronding the mini-screw, and the tooth, that undergoes stress. Furthermore, quantitative analysis of stress could exclude failure in alveolar bone and detachment at the enamel-bracket interface. The applied force and devices were proved to be safe to use for this kind of orthodontic facilities.

Feedback reliance during an arm-tapping task with obstacle avoidance in adults with Down syndrome

Optimal movement control reflects a combination of both feedback and feedforward processes. However, as motor control evolves, feedforward mechanisms become prevailing respect to feedback-based movements, and less reliance on sensory information leads to a decreased number of corrections in the trajectory. In subjects with Down syndrome (DS), the study of the wrist’s trajectory during an arm-tapping task revealed feedback-based corrections designed to reduce the degree of discrepancy between the position of the limb and the target, leading to the assumption that performers with DS have problems with movement planning and feedforward control. The present study was aimed at expanding the evidence about motor control in DS by evaluating the influence of a perturbing factor (an obstacle) on motor control strategies during an arm-tapping task and to clarify if the presence of an obstacle elicited a higher reliance on feedback control in controls and in DS. Sixteen right-handed adults with DS and 21 right-handed, age-matched control subjects (N) were evaluated by means of quantitative motion analysis. The results suggest that the presence of an obstacle elicited changes in the motor strategies of both DS and N, with a destabilizing effect that led subjects to rely more on feedback control. DS showed some aspects of movement efficiency that were in accordance with N strategies, but the prevailing factor of optimization in these subjects remained safety. A focused rehabilitation could help DS subjects to develop more efficient motor strategies in the presence of motor uncertainty and perturbations.

Temporomandibular joint mobility in adult females with Ehlers-Danlos syndrome, hypermobility type (also known as joint hypermobility syndrome)

Context: It is well-known that subjects affected by Ehlers-Danlos Syndrome (EDS), hypermobility type/Joint Hypermobility Syndrome are characterized by severe joint hypermobility with recurrent joint dislocations and chronic pain and biomechanical dysfunction of the temporo-mandibular joint (TMJ). Aims: The study aims to measure TMJ mobility in EDS subjects to quantitatively characterize the TMJ dislocation during specific tasks as well as head adjustments, already documented by literature by observational techniques. Materials and Methods: Female EDS subjects and age matched controls were asked to perform simple opening-closing movements of the mandible. Kinematics data was recorded and analyzed through an optoelectronic motion capture system. Some parameters of the motion were studied: range of motion of the condyles, range of motion of the chin, aperture angle, movement speed, and frequency. Statistical Analysis Used: The statistical t-test was used to compare results from pathological group to the control group. Results: Significant differences, between EDS group and controls, were found for the backward rotation of the head, lateral range of motion of the chin, frequency, and velocity. Results were in accordance with the clinical observations. The results not only confirmed that EDS subjects back-rotate the head while performing the opening-closing task but also quantified the entity of this behavior. Conclusions: The method we proposed is noninvasive and is able to analyze mandible kinematics. It may be used by clinicians to assess the healthy status of TMJ, to quantify mobility, and hypermobility of the mandible and to help diagnosis of TMJ dysfunctions.

Analysis of Knee Strength Measurements Performed by a Hand-Held Multicomponent Dynamometer and Optoelectronic System

The quantification of muscle weakness is useful to evaluate the health status and performance of patients and athletes. In this paper, we proposed a novel methodology to investigate and to quantify the effects induced by inaccuracy sources occurring when using a hand-held dynamometer (HHD) for knee strength measurements. The validation methodology is based on the comparison between the output of a one-component commercial HHD and the outputs of a six-component load cell, comparable in dimension and mass. An optoelectronic system was used to measure HHD positioning angles and displacements. The setup allowed to investigate the effects induced by: the operators ability to place and to hold still the HHD and ignoring the transversal components of the force exchanged. The main finding was that the use of a single component HHD induced an overall inaccuracy of 5% in the strength measurements if the angular misplacements are kept within the values found in this paper (≤15°) and with a knee range of motion ≤22°. Extension trials were the most critical due to the higher force exerted, i.e., 249.4 ± 27.3 versus 146.4 ± 23.9 N of knee flexion. The most relevant source of inaccuracy was identified in the angular displacement on the horizontal plane.

Analysis of gait patterns pre- and post- Single Event Multilevel Surgery in children with Cerebral Palsy by means of Offset-Wise Movement Analysis Profile and Linear Fit Method

Gait analysis is used for the assessment of walking ability of children with cerebral palsy (CP), to inform clinical decision making and to quantify changes after treatment. To simplify gait analysis interpretation and to quantify deviations from normality, some quantitative synthetic descriptors were developed over the years, such as the Movement Analysis Profile (MAP) and the Linear Fit Method (LFM), but their interpretation is not always straightforward. The aims of this work were to: (i) study gait changes, by means of synthetic descriptors, in children with CP that underwent Single Event Multilevel Surgery; (ii) compare the MAP and the LFM on these patients; (iii) design a new index that may overcome the limitations of the previous methods, i.e. the lack of information about the direction of deviation or its source. Gait analysis exams of 10 children with CP, pre- and post-surgery, were collected and MAP and LFM were computed. A new index was designed asa modified version of the MAP by separating out changes in offset (named OC-MAP). MAP documented an improvement in the gait pattern after surgery. The highest effect was observed for the knee flexion/extension angle. However, a worsening was observed as an increase in anterior pelvic tilt. An important source of gait deviation was recognized in the offset between observed tracks and reference. OC-MAP allowed the assessment of the offset component versus the shape component of deviation. LFM provided results similar to OC-MAP offset analysis but could not be considered reliable due to intrinsic limitations. As offset in gait features played an important role in gait deviation, OC-MAP synthetic analysis was proposed as a novel approach to a meaningful parameterisation of global deviations in gait patterns of subjects with CP and gait changes after treatment.

Stereophotogrammetry in Functional Evaluation: History and Modern Protocols

This chapter contains a brief survey on the history of motion analysis and a review of the earliest experiments in biomechanics. The most famous historical works, mainly based on photography, are described. As most of the modern research in functional evaluation and biomechanics is mainly based on the use of optoelectronic systems, the working principle of such systems is reviewed as well as their application and setup in clinical practice. Some modern functional evaluation protocols are reviewed. These include: (i) the quantitative evaluation of physical performance; (ii) the analysis of small movements, such as handwriting or facial expressions; and (iii) other protocols aimed at the clinical diagnosis of motor disorders. Special attention is paid to a common motion analysis exam that is nowadays standardised worldwide: gait analysis. Examples of gait analysis studies on subjects with pathology and follow-up are reviewed, and the clinical interpretation of gait analysis and methods to quantify deviation from normality are discussed in Chap. 3.