Trunk Inclination Estimate During the Sprint Start Using an Inertial Measurement Unit: A Validation Study

The proper execution of the sprint start is crucial in determining the performance during a sprint race. In this respect, when moving from the crouch to the upright position, trunk kinematics is a key element. The purpose of this study was to validate the use of a trunk-mounted inertial measurement unit (IMU) in estimating the trunk inclination and angular velocity in the sagittal plane during the sprint start. In-laboratory sprint starts were performed by five sprinters. The local acceleration and angular velocity components provided by the IMU were processed using an adaptive Kalman filter. The accuracy of the IMU inclination estimate and its consistency with trunk inclination were assessed using reference stereophotogrammetric measurements. A Bland-Altman analysis, carried out using parameters (minimum, maximum, and mean values) extracted from the time histories of the estimated variables, and curve similarity analysis (correlation coefficient > 0.99, root mean square difference < 7 deg) indicated the agreement between reference and IMU estimates, opening a promising scenario for an accurate in-field use of IMUs for sprint start performance assessment

Estimation of temporal parameters during sprint running using a trunk-mounted inertial measurement unit

This research was supported by a grant of the Universit a Italo-Francese (Call Vinci) awarded to E. Bergamini.The purpose of this study was to identify consistent features in the signals supplied by a single inertial measurement unit (IMU), or thereof derived, for the identification of foot-strike and foot-off instants of time and for the estimation of stance and stride duration during the maintenance phase of sprint running. Maximal sprint runs were performed on tartan tracks by five amateur and six elite athletes, and durations derived from the IMU data were validated using force platforms and a high-speed video camera, respectively, for the two groups. The IMU was positioned on the lower back trunk (L1 level) of each athlete. The magnitudes of the acceleration and angular velocity vectors measured by the IMU, as well as their wavelet-mediated first and second derivatives were computed, and features related to foot-strike and foot-off events sought. No consistent features were found on the acceleration signal or on its first and second derivatives. Conversely, the foot-strike and foot-off events could be identified from features exhibited by the second derivative of the angular velocity magnitude. An average absolute difference of 0.005 s was found between IMU and reference estimates, for both stance and stride duration and for both amateur and elite athletes. The 95% limits of agreement of this difference were less than 0.025 s. The results proved that a single, trunk-mounted IMU is suitable to estimate stance and stride duration during sprint running, providing the opportunity to collect information in the field, without constraining or limiting athletes’ and coaches’ activities

ESTIMATE OF TRUNK INCLINATION DURING FAST MOVEMENTS BY INERTIAL SENSING

The purpose of this study was to identify a reliable algorithm to estimate the inclination of a trunk-mounted inertial measurement unit (IMU) during fast movements and to test its subject- and task-specificity. Ten amateur football players performed three times the approach phase of the drive block technique and a fast sit-to-stand-to-sit task. IMU data were processed using an ad hoc adaptive Kaman filter, and pitch angular displacements were obtained and compared to stereophotogrammetric reference estimates. Tuning of the algorithm parameters was performed and relevant accuracy was tested in terms of root mean squared difference (RMSD) and correlation coefficient. Strong correlation (>0.978) were observed for both motor tasks, together with RMSD smaller than 4.4±1.7 deg. The tuned algorithm proved to be neither subject- nor task-specific (p>0.05)

Iron Metabolism in the Disorders of Heme Biosynthesis

Given its remarkable property to easily switch between different oxidative states, iron is essential in countless cellular functions which involve redox reactions. At the same time, uncon- trolled interactions between iron and its surrounding milieu may be damaging to cells and tissues. Heme—the iron-chelated form of protoporphyrin IX—is a macrocyclic tetrapyrrole and a coordina- tion complex for diatomic gases, accurately engineered by evolution to exploit the catalytic, oxygen- binding, and oxidoreductive properties of iron while minimizing its damaging effects on tissues. The majority of the body production of heme is ultimately incorporated into hemoglobin within mature erythrocytes; thus, regulation of heme biosynthesis by iron is central in erythropoiesis. Additionally, heme is a cofactor in several metabolic pathways, which can be modulated by iron- dependent signals as well. Impairment in some steps of the pathway of heme biosynthesis is the main pathogenetic mechanism of two groups of diseases collectively known as porphyrias and congenital sideroblastic anemias. In porphyrias, according to the specific enzyme involved, heme precursors accumulate up to the enzyme stop in disease-specific patterns and organs. Therefore, different por- phyrias manifest themselves under strikingly different clinical pictures. In congenital sideroblastic anemias, instead, an altered utilization of mitochondrial iron by erythroid precursors leads to mito- chondrial iron overload and an accumulation of ring sideroblasts in the bone marrow. In line with the complexity of the processes involved, the role of iron in these conditions is then multifarious. This review aims to summarise the most important lines of evidence concerning the interplay be- tween iron and heme metabolism, as well as the clinical and experimental aspects of the role of iron in inherited conditions of altered heme biosynthesis

Successful Pregnancy Outcome after Laparoscopic Cerclage in a Patient with Cervicovaginal Fistula

Obstetric fistula usually originates from obstructed labor or, less often, from invasive maneuvers on the genital tract or the pregnant uterus. Overall, it is a rare finding in the obstetric practice of high income countries. In this report we describe the case of a successful term pregnancy in a patient with a history of recurrent late miscarriage due to a large cervical fistula of traumatic origin, connecting the uterine cavity and the posterior vaginal fornix. A combined approach of laparoscopic cerclage and transvaginal fistula repair effectively restored cervical competence and created the conditions for a viable birth in a subsequent pregnancy. This unusual cause of cervical incompetence may be included in the indications which benefit from an abdominal cerclage carried out as a minimally invasive procedure in the nonpregnant state

Development of a wearable framework for body center of mass acceleration assessment in people with transfemoral amputation

The biomechanical study of the body center of mass (BCoM) may reveal crucial information about gait impairment in people with amputation (Al Abiad et al. 2020). The 3D kinetics of the BCoM are usua..

Definition of an optimal model based on segments' contribution for the estimation of the acceleration of the center of mass in people with lower-limb amputation

In the context of rehabilitation of people with amputation, gait analysis provides information about gait alterations. In that perspective, the body center of mass (BCoM) trajectory, or its derivat..

Engaging with stakeholders for initiating agroecological transition in Living Landscapes: Six guiding principles

In the Agroecology initiative, work package 1 (WP1) is responsible for ALL establishment. From the very beginning, during the initiative kick-off workshop in March 2022, the country leads of the seven countries in which the initiative operates agreed with WP1 coordination that the ALLs could not be established by applying a standard approach or methodology. Indeed, differences in the current state, trajectory, and human resources in terms of advancing agroecology and implementing multistakeholder approaches in each country need to be considered. Also, by its very design, the Agroecology Initiative intends to have strong national and local partners in each country, which are to contribute to developing the Initiative’s objectives and local implementation strategy. It was hence decided collectively that the ALL establishment could best be guided through the identification of common engagement principles that each country team could use flexibly to shape and guide its approach and related actions. In other words, considerations and principles presented in this guide may apply differently in each country and it is up to each country team to decide how to make use of them for achieving their objectives. Following this rationale, this document presents the six guiding principles that were eventually identified. After introducing each principle, the document presents generic steps and specific considerations or suggestions for their operationalization/implementation

AN INERTIAL SENSORS-BASED METHOD FOR PHASES AND EVENTS IDENTIFICATION IN PARA-ROWING: TOWARDS AN ON-WATER PERFORMANCE ASSESSMENT

The aim of this study is to propose and validate an inertial sensors-based methodology for the para-rowing stroke cycles segmentation. One non-disabled athlete performed two para-rowing set-ups, simulating PR1 (arms and shoulders-AS) and PR2 (trunk and arms-TA) conditions. Catch and finish events of each stroke cycle were identified on the signals measured by three sensors located on the right forearm (FA), upper arm (UA), and on the trunk (T). Accuracy was quantified by identifying the same events on the 3D trajectory of one right hand-located marker. UA and FA sensors data lead to a more accurate detection of stroke events with respect to the T sensor (average error: 28.8ms, 29.0ms, 56.9ms). The present results open promising scenarios on the application of inertial sensors in para-rowing for real-time performance-related feedback to athletes and coaches