Poster Session III, July 15th 2010 — Abstracts Inertial sensors in sports: application to vertical jumps

Abstract Countermovement jump (CMJ) height is typically estimated by applying the equation of free-fall to the motion of the centre of mass (CM) during the flight phase. In field setting, this is generally done using optical cells/contact mats. The reliability of the estimate is strongly affected by the subject's expertise in executing the jump. Wearable inertial measurement units (IMU), containing 3D accelerometers and gyroscopes, can provide similar information regardless to execution constraints. However, the interpretation of signals still requires the development of computational techniques and of models embodying the specific motor task. This study aims to verify whether IMU can be used to assess CMJ performance. Twenty-eight college students (67±13 kg, 1.73±0.09 m) performed 5 CMJ, with a 3-min rest in between. A wireless IMU (Sensorize, Italy) was placed using an elastic belt around the trunk at L5 level. Sensor accelerations, influenced by trunk bending, were expressed in a global reference system using the gyroscopes. Flight time (T) was identified when the vertical acceleration (az) was lower than gravity. Subsequent numerical integration of az provided velocity and height of the centre of mass at take-off. These quantities and the ballistic law of motion were used to estimate jump height (H). A stereophotogrammetric system (Vicon MX, UK) and a force plate (Bertec, USA) were used to obtain reference values for H (Hr) and T (Tr). ANOVA for repeated measurements ( p 0.05 ) and Pearson's correlation coefficient evaluated statistical differences between H and Hr and T and Tr, respectively. Intra-individual reliability was assessed by means of the Intraclass Correlation Coefficient (ICC). IMU and reference values were highly correlated (H: r = 0.9 ; T: r = 0.9 ) and presented no statistical difference for both H and T. Relevant differences were 2±8% and 4±3% for H and T, respectively. High intra-subject IMU reliability was found (ICCJ=0.834, ICCT=0.868). This study showed how the combination of a 3D accelerometer and gyroscope can lead to an accurate and repeatable estimate of jump height. CMJ height estimate does not suffer from any assumption about the performed task and it is not affected by the subject's expertise (reliable for elderly and young populations). Furthermore, since the IMU is worn by the athlete, vertical jumps can be performed on any surfaces such as grass, sand, springboards, etc

SPATIO-TEMPORAL PARAMETERS AND INSTANTANEOUS VELOCITY OF SPRINT RUNNING USING A WEARABLE INERTIAL MEASUREMENT UNIT

INTRODUCTION: Wearable inertial measurement units (IMU) provide movement-related data without any space limitation or cumbersome setup. They can be proficiently used to perform an in-field biomechanical analysis of sprint running providing information useful for performance optimisation and injury prevention. Mechanical key quantities characterizing sprint running performance are instantaneous velocity and displacement of the athlete (Cavagna et al., 1971). However, the process of determining velocity and position by numerical integration of acceleration is jeopardized by the noise characterizing the signal of micro-machined accelerometers (Thong et al., 2002). The aim of this study was to compensate these errors by reducing the integration interval, taking advantage of a priori known laws of motion, and by cyclically determining the initial conditions of the integration process, in order to yield reliable spatio-temporal parameters during sprint running. METHODS: A male subject (26 yrs, 73 kg, 1.73 m) performed 7 in-lab sprints, starting from a standing position. Due to limited lab volume (12*9*4 m) only the first 3 steps were considered. 3D linear acceleration and orientation of a wearable IMU positioned on the upper back trunk (MTx, Xsens; m=30g) were collected and the following parameters were estimated over each cycle: 1) stance time (ST); 2) centre of mass progression displacement (d); 3) variation of vertical and progression velocity (Δvv, Δvp). Reference data were obtained as follows: ST from a contact-sensitive mat (stance 1) and two force platforms (Bertec) (stance 2-3); Δv and d from stereophotogrammetry (Vicon MX, Plug-in-Gait protocol). The average of the absolute percentage difference (eabs%=|(reference-inertial)*100/reference|), referred to as error (e%), was calculated for each parameter. RESULTS: Reference and sensor estimates and percentage error are reported in Table 1. DISCUSSION AND CONCLUSION: The obtained Δv percentage errors are consistent with respect to the literature (Vetter et al., 2008). Even though these errors still increase at each stance phase, the methodology is sensitive to the variations of velocity determined by the reference measurement system. As regards ST and d, no similar previous study has been reported. However since the methodology relies on the identification of foot contact timings for reducing the integration interval, small errors in the determination of these parameters, are encouraging. Future developments concern in-field sprint running experimental sessions

Prevalence of Baker's cyst in patients with knee pain: an ultrasonographic study

The objectives of this study are to investigate the prevalence of Baker's cyst (BC) in patients with knee pain, and to assess the correlation between BC and severity of osteophytes and joint effusion. A retrospective study was conducted on a group of patients with knee pain referred to our outpatient clinic for ultrasonography of the knee between January 2010 and February 2011. Patients underwent an ultrasonographic exam of the knees to assess the presence of marginal femorotibial osteophytosis, joint effusion and BC. A dichotomous score was assigned to each item (1 present, 0 absent) and severity of US signs of osteoarthritis and joint effusion were also graded semiquantitatively. Collected data were processed using logistic regression analysis to evaluate the correlation between degree of osteophytosis and joint effusion and BC. Patients affected by inflammatory joint conditions or with history of joint surgery or recent trauma were excluded. A total of 399 patients with knee pain were studied (299 women), in the age range 18-89 years (mean 56.2, SD 16.3 years). 293 patients (73.4%) showed sonographic features of osteoarthritis and 251 (62.9%) joint effusion. BC was found in 102 patients (25.8%) together with a positive association with sonographic features of osteoarthritis and joint effusion. Our data show a prevalence of BC of 25.8% in a population of patients with knee pain, and suggest that BC is positively related to osteoarthritis and joint effusion. Ultrasonographic examination of knee is worthwhile in patients with painful osteoarthritis or evidence of effusion

Ultrasound in the diagnosis of calcium pyrophosphate dihydrate deposition disease. A systematic literature review and a meta-analysis

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SAT0625 Ultrasound assessment of joints and enthesis in a cohort of patients affected by ochronosis: how common is inflammation?

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Post-graduate medical education in public health: The case of Italy and a call for action

Public health technical expertise is of crucial importance to inform decision makers\u2019 action in the field of health and its broader determinants. Improving education and training of public health professionals for both practice and research is the starting point to strengthen the role of public health so that current health challenges can be efficiently tackled. At the Association of Schools of Public Health in the European Region (ASPHER) Deans\u2019 & Directors\u2019 2017 Annual Retreat, we presented the structure and management of public health training system in Italy, and we reported recent data on Italian public health specialists\u2019 educational experience, employment opportunities and job satisfaction. Public health training in Italy is implemented in the context of the post-graduate medical education residency programme in Hygiene and Preventive Medicine, delivered by 34 University-based Schools of Public Health. We report relatively high employment rates across the county and wide spectrum of career opportunities for young public health specialists. However, job security is low and training expectations only partially met. We call upon other Schools of Public Health to scale up the survey within the broad ASPHER community in a shared and coordinated action of systematically collecting useful data that can inform the development of public health education and training models, their implementation and fruitful interaction with population health, health systems and services

Effectiveness of Golimumab as Second Anti-TNFα Drug in Patients with Rheumatoid Arthritis, Psoriatic Arthritis and Axial Spondyloarthritis in Italy: GO-BEYOND, a Prospective Real-World Observational Study

In this prospective observational study, data were collected from 34 rheumatology clinics in Italy in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) who started golimumab (GLM) as a second anti-TNFα drug. The primary objective was to evaluate the effectiveness of GLM after 6 months. Changes in quality of life using the EQ-5D-5L were also assessed. A total of 194 patients aged 53.2 ± 12 years started GLM as a second anti-TNF drug: 39 (20.1%) with RA, 91 (46.9%) with PsA and 64 (32.9%) with axSpA. After 6 months of GLM treatment, 68% of RA patients achieved low disease activity (LDA; DAS28-CRP ≤ 3.2), 31.9% of PsA patients achieved minimal disease activity and 32.5% of axSpA patients achieved LDA (ASDAS-CRP < 2.1). Good/moderate EULAR response was achieved in 61.9% and 73.8% of patients with RA and PsA, respectively, and 16% of axSpA patients achieved a 50% improvement in BASDAI. Across all indications, improvements in disease activity measures and EQ-5D-5L domains were observed over 6 months. The main reasons for GLM interruption were lack/loss of efficacy (7.2%) or adverse events (2%). This study confirms the effectiveness of GLM as a second-line anti-TNF for the treatment of RA, PsA and axSpA in a real-world setting in Italy

Relationship between the prevalence of subclinical tenosynovitis and treatment in patients with RA in clinical remission: STARTER study

Objective: This study is a sub-analysis from the patient cohort of the STARTER (Sonographic Tenosynovitis Assessment in RheumaToid arthritis patiEnts in Remission) study. The aim was to evaluate differences in ultrasound-detected joint and/or tendon involvement between patients receiving therapies based on a combination of conventional synthetic DMARDs (csDMARDs) and biologic DMARDs (bDMARDs) and those who were treated with either csDMARDs or bDMARDs in monotherapy. Material and methods: Four hundred and twenty-seven consecutive patients with a diagnosis of RA were recruited between October 2013 and June 2014. They were divided into three subgroups based on their therapy at baseline: patients with bDMARD in monotherapy, patients with csDMARD in monotherapy and patients in combination therapy (csDMARD + bDMARD). At baseline, 6 months and 12 months, a clinical examination (28 joint count) and an ultrasound evaluation were performed in each patient. A score of grey-scale (GS) and power Doppler (PD) synovitis and tenosynovitis was calculated based on the OMERACT scoring systems. Results: Two hundred and fifty-six patients completed the observation period: 48 patients from the bDMARD group (18.75%), 152 patients from the csDMARD group (59.38%) and 56 patients from csDMARD + bDMARD group (21.88%). The analysis showed that GS tenosynovitis and PD tenosynovitis are better controlled in combination therapy than they are ith csDMARD alone (P=0.025 and P=0.047, respectively); for PD synovitis, there was a better response in those who were treated with the combination therapy when compared with the patients receiving csDMARD (P=0.01) or bDMARD (P=0.02) alone. Conclusions: The analysis showed a lower prevalence of subclinical inflammatory manifestations detected with ultrasound imaging in those patients treated with the combination therapy than in those in monotherapy