Antônio Eustáquio de Melo Pertence

Muscle stiffness and strength and their relation to hand function in children with hemiplegic cerebral palsy

This study compared the passive stiffness of wrist flexors and the strength of wrist flexors and extensors in three different wrist positions (30 degrees of flexion, neutral, and 30 degrees of extension) between children with cerebral palsy (CP) and typically developing (TD) comparison children. It also examined associations between these characteristics and manual function in children with CP. Eleven children with spastic hemiplegic CP (six females, five males; mean age 8y 5mo [SD 1y 8mo], range 6-11y) and 11 TD children, matched for age and sex, took part in this study. Passive stiffness of muscles was measured as the torque/angle relation during passive motion. Isometric strength tests were performed and the time needed to complete three tasks based on the Jebsen-Taylor Hand Function Test was recorded. Flexor stiffness was higher in the group with CP. Strength of flexors and extensors in the group with CP was lower with the wrist extended. No difference among test positions was found in the TD group. Moderate correlations were observed between manual function and variables related to strength and stiffness of wrist muscles in the group with CP. Children with CP showed muscle alterations coherent with the use of the wrist in flexion. Intervention on these characteristics could have a positive impact on manual function.

On the utilisation of ductile fracture criteria in cold forging

In most cold forging operations, formability is limited by ductile fracture. This paper describes the utilisation of ductile fracture criteria in conjunction with the finite element method to predict when and where material is likely to fracture during cold forging. Several previously published ductile fracture criteria are selected, and their values of critical damage at the levels of deformation at which fracture starts are obtained through a series of experimental upset tests comprising cylindrical, tapered and flanged geometries. The experiments are also used to investigate the validity and the relative accuracy of each criterion under loading conditions of stress and strain similar to those usually found in cold forging.

Late Rearfoot Eversion and Lower-limb Internal Rotation Caused by Changes in the Interaction between Forefoot and Support Surface

BACKGROUND The influence of distal mechanical factors that change the interaction between the forefoot and the support surface on lower-limb kinematics is not well established. This study investigated the effects of the use of lateral wedges under the forefoot on the kinematics of the lower extremity during the stance phase of walking. METHODS Sixteen healthy young adults participated in this repeated-measures study. They walked wearing flat sandals and laterally wedged sandals, which were medially inclined only in the forefoot. One wedged sandal had a forefoot lateral wedge of 5 degrees and the other wedged sandal had a forefoot lateral wedge of 10 degrees. Kinematic variables of the lower extremity, theoretically considered clinically relevant for injury development, were measured with a three-dimensional motion analysis system. The variables were evaluated for three subphases of stance: loading response, midstance, and late stance. RESULTS The 5 degrees laterally wedged sandal increased rearfoot eversion during midstance and the 10 degrees laterally wedged sandal increased rearfoot eversion during mid- and late stances, in comparison to the use of flat sandals. The 10 degrees laterally wedged sandal produced greater internal rotation of the shank relative to the pelvis and of the hip joint, during the midstance, also compared to the use of flat sandals. CONCLUSIONS Lateral wedges under the forefoot increase rearfoot eversion during mid-and late stances and may cause proximal kinematic changes throughout the lower-extremity kinetic chain. Distal mechanical factors should be clinically addressed when a patient presents late excessive rearfoot eversion during walking.

New method of scoliosis assessment: preliminary results using computerized photogrammetry.

Study Design. A new method for nonradiographic evaluation of scoliosis was independently compared with the Cobb radiographic method, for the quantification of scoliotic curvature. Objective. To develop a protocol for computerized photogrammetry, as a nonradiographic method, for the quantification of scoliosis, and to mathematically relate this proposed method with the Cobb radiographic method. Summary of Background Data. Repeated exposure to radiation of children can be harmful to their health. Nevertheless, no nonradiographic method until now proposed has gained popularity as a routine method for evaluation, mainly due to a low correspondence to the Cobb radiographic method. Methods. Patients undergoing standing posteroanterior full-length spine radiographs, who were willing to participate in this study, were submitted to dorsal digital photography in the orthostatic position with special surface markers over the spinous process, specifically the vertebrae C7 to L5. The radiographic and photographic images were sent separately for independent analysis to two examiners, trained in quantification of scoliosis for the types of images received. The scoliosis curvature angles obtained through computerized photogrammetry (the new method) were compared to those obtained through the Cobb radiographic method. Results. Sixteen individuals were evaluated (14 female and 2 male). All presented idiopathic scoliosis, and were between 21.4 ± 6.1 years of age; 52.9 ± 5.8 kg in weight; 1.63 ± 0.05 m in height, with a body mass index of 19.8 ± 0.2. There was no statistically significant difference between the scoliosis angle measurements obtained in the comparative analysis of both methods, and a mathematical relationship was formulated between both methods. Conclusion. The preliminary results presented demonstrate equivalence between the two methods. More studies are needed to firmly assess the potential of this new method as a coadjuvant tool in the routine following of scoliosis treatment.

Muscle co-contraction after anterior cruciate ligament reconstruction: Influence of functional level

BACKGROUND ACL reconstruction is recommended to improve function in subjects with ligament injuries. However, after surgery, some individuals are not able to return to their pre-injury functional level. The mechanisms related to this incapacity are not well understood. STUDY DESIGN Cross-sectional study. METHODS Co-contraction levels were assessed in individuals who returned to their pre-injury functional level and in 10 individuals who were not able to return to full activity after unilateral ACL reconstruction. Electromyography of the vastus lateralis and biceps femoris muscles before and after sudden perturbations applied during the stance phase of walking was used to calculate co-contraction. RESULTS The involved limb had lower co-contraction pre-perturbation than the non-involved limb in both groups (p=0.049). The co-contraction level post-perturbation was significantly higher in the limited return group than in the full return group (p=0.03). CONCLUSION Decreased co-contraction in the involved limb before perturbation may be caused by sensorial changes resulting from surgery or injury. Increased co-contraction levels observed in the limited return group after perturbation may be a compensatory mechanism to make up for possible decreased intrinsic stability of the knee joint. CLINICAL RELEVANCE Increased co-contraction after perturbation does not contribute to knee stability.

Non-invasive methods of computer vision in the posture evaluation of adolescent idiopathic scoliosis

PURPOSE Reviewing techniques for non-invasive postural evaluation of adolescent idiopathic scoliosis (AIS) based on information extraction from images based on computer methods. METHODS The Scopus, Web of Science, MEDLINE, ScieLo and PubMed databases were used, for the period 2011-2015. RESULTS 131 articles were found based on keyword of which 15 articles met the established eligibility criteria. Of these, 4 were based on photogrammetry, and 11 based on laser, structured light, ultrasound, and Moiré projection. In these studies, the methodological quality varied from low to high. CONCLUSIONS The findings indicated diversity in methodologies; 14/15 articles reviewed were limited to the evaluation of the topography of the posterior back. A study, using two-dimensional photogrammetry, presented a whole body postural evaluation. As the asymmetry in AIS can be extended to the whole body, more attention should be given to develop full body assessment techniques to provide important additional data to aid in treatment decisions.

Evaluation of cognitive technologies in geriatric rehabilitation: a case study pilot project

The aim of this study was to develop and evaluate low-cost technology for cognitive rehabilitation in older individuals with dementia and document changes stemming from a clinical case study using these tools. An activity board, a calendar, a routine organizer and a software program were used and evaluated by specialists (n = 7). A pre-post-case study with an elderly male with dementia was undertaken for four months. All rehabilitation resources were classified as appropriate by the specialists. Post-intervention scores demonstrated improvement in cognitive functioning and daily activities at home. There is a need for further research to assess the therapeutic effects in patients with dementia applying equipment and software to improve cognitive function.

Viscoelastic stress relaxation in the hamstrings before and after a 10-week stretching program.

We investigated the viscoelastic stress relaxation response before and after a 10‐week hamstrings static stretch program. Methods: The maximal range of motion (ROMmax) and maximal torque (Torquemax) were assessed before and after a 10‐week stretching program. Six 30‐s static stretches at a predetermined torque were performed, and the relative change in stress relaxation was examined. Results: ROMmax and Torquemax increased by 53% and 82%, respectively (P < 0.001). The relative stress relaxation (RSR) decreased significantly for repetition 1 when comparing the pretest (25%) and posttest (21%) values (P = 0.003). A significant decrease was also observed for repetitions 2 and 3 (P < 0.014), with no significant difference in repetitions 4–6 (P > 0.056). Conclusions: Individuals who participated in a 10‐week hamstrings passive–static stretch program had a reduced RSR response. A higher stretch intensity or longer duration may be necessary to achieve RSRs similar to those reported before the stretch program. Muscle Nerve, 2015 Muscle Nerve 51:761–764, 2015

Accuracy of photogrammetry for detecting adolescent idiopathic scoliosis progression

BACKGROUND The gold standard method of monitoring the evolution of scoliosis has been serial standing, posteroanterior, full-length spine radiographs with curvature measurements using the Cobb method. However, over the course of follow-up, patients can receive high radiation doses. Various studies have shown that repeated exposure to radiation in children and adolescents can be harmful to their health. PURPOSE To determine the accuracy of photogrammetry in evaluating the progression of adolescent idiopathic scoliosis in comparison with radiography. STUDY DESIGN Diagnostic study. PATIENT SAMPLE Ninety adolescents subjected to radiographic follow-up of idiopathic scoliosis. OUTCOME MEASURES The angle of scoliotic curvature was measured using the Cobb radiographic method and photogrammetry. An increase of 5° or more between two radiographic exams was considered a progression of the curvature and was defined as the standard for calculations of sensitivity, specificity, predictive value, and accuracy of the photogrammetric method for measuring scoliosis progression. METHODS Patients were subjected to radiographic and photogrammetric exams concomitantly and were reevaluated after an average of 8.6 months. The exams were analyzed separately and independently by two examiners for progression of scoliosis. RESULTS The measurements of the curves at the beginning of the study were 39.5±16.7° and 39.5±14.3° for radiographic and photogrammetric exams, respectively (p=1.0). At the end of the study, the measurements of the curves were 40.2±16.2° and 41.3±15.1° for the radiographic and photogrammetric exams, respectively (p=.310). The photogrammetric method had an accuracy of 89% (Confidence interval [CI] 95%=82.5-95.5) for the detection of scoliosis progression, with a sensitivity of 94.4% (CI 95%=89.6-99.2), a specificity of 86.7% (CI 95%=79.7-93.7), a positive predictive value of 75.5% (CI 95%=66.6-84.4), a negative predictive value of 97.2% (CI 95%=93.8-100), and a Kappa index of 0.75 (CI 95%=66.1-83.9). The interclass correlation coefficient between the two methods was 0.74 (CI 95%=0.65-0.81; p=0). CONCLUSIONS The photogrammetric method showed good performance for detecting the progression of adolescent idiopathic scoliosis in comparison with the radiographic exam method.

Three-dimensional geometric model of the middle segment of the thoracic spine based on graphical images for finite element analysis

Abstract Introduction : Biomedical studies involve complex anatomical structures, which require specific methodology to generate their geometric models. The middle segment of the thoracic spine (T5-T10) is the site of the highest incidence of vertebral deformity in adolescents. Traditionally, its geometries are derived from computed tomography or magnetic resonance imaging data. However, this approach may restrict certain studies. The study aimed to generate two 3D geometric model of the T5-T10 thoracic spine segment, obtained from graphical images, and to create mesh for finite element studies. Methods : A 3D geometric model of T5-T10 was generated using two anatomical images of T6 vertebra (side and top). The geometric model was created in Autodesk  Maya 3D 2013, and the mesh process in HiperMesh and MeshMixer (v11.0.544 Autodesk). Results : The T5-T10 thoracic segment model is presented with its passive components, bones, intervertebral discs and flavum, intertransverse and supraspinous ligaments, in different views, as well as the volumetric mesh.