1,721,014 research outputs found
Countermovement jump performance assessment using a wearable 3D inertial measurement unit
No full textThe aim of this study was to validate a wearable inertial measurement unit (IMU), containing a 3D accelerometer and gyroscope, for the estimation of countermovement jump height. The absolute vertical acceleration of the IMU positioned on the back of the participant at L5 level, compensated for trunk rotations, was used to obtain jump height by applying the equation of free-fall to the motion of the IMU. The methodology was tested on 28 participants performing five countermovement jumps each. A reference value for this quantity was obtained using stereophotogrammetry (35.4 cm, s = 4.9). Jump height scores obtained using the proposed methodology (35.9 cm, s = 5.5) presented no significant difference with respect to stereophotogrammetry (P = 0.61). A low bias of 0.6 cm confirmed the accuracy of the estimate, which also showed a high (r = 0.87) and significant (P < 0.0001) correlation with reference values. Furthermore, without compensating accelerations for trunk rotation, jump height was largely underestimated (P < 0.0001) (bias: -12.7 cm) and poorly associated (r = 0.31) with stereophotogrammetry. The results of this study show that the estimation of jump height using inertial sensors leads to accurate results when the measured accelerations are corrected for trunk rotations
Trends Supporting the In-Field Use of Wearable Inertial Sensors for Sport Performance Evaluation: A Systematic Review
Get PDFRecent technological developments have led to the production of inexpensive, non-invasive, miniature magneto-inertial sensors, ideal for obtaining sport performance measures during training or competition. This systematic review evaluates current evidence and the future potential of their use in sport performance evaluation. Articles published in English (April 2017) were searched in Web-of-Science, Scopus, Pubmed, and Sport-Discus databases. A keyword search of titles, abstracts and keywords which included studies using accelerometers, gyroscopes and/or magnetometers to analyse sport motor-tasks performed by athletes (excluding risk of injury, physical activity, and energy expenditure) resulted in 2040 papers. Papers and reference list screening led to the selection of 286 studies and 23 reviews. Information on sport, motor-tasks, participants, device characteristics, sensor position and fixing, experimental setting and performance indicators was extracted. The selected papers dealt with motor capacity assessment (51 papers), technique analysis (163), activity classification (19), and physical demands assessment (61). Focus was placed mainly on elite and sub-elite athletes (59%) performing their sport in-field during training (62%) and competition (7%). Measuring movement outdoors created opportunities in winter sports (8%), water sports (16%), team sports (25%), and other outdoor activities (27%). Indications on the reliability of sensor-based performance indicators are provided, together with critical considerations and future trends
Measurement and extraction of motion-related quantities in sport
No full textHuman movement analysis technology, including stereophotogrammetric motion capture, 2D and 3D video camera reconstruction, global navigation satellite and local positioning systems (GNSS, and LPS), and magneto-inertial sensors (MIMUs) has revolutionized the field of sports by providing scientists, coaches, and athletes with invaluable insights into athletes’ movement patterns. Thanks to movement analysis, feedback on biomechanical inefficiencies may be obtained to optimize sports techniques and prevent the risk of injuries, and athletes’ performances may be compared among peers or over time, aiding in the evaluation of training interventions and performance progression. This chapter spans from describing laboratory assessments, performed with motion capture in controlled conditions, to in-field assessments, performed in ecological conditions by 2D/3D video analysis, positioning systems and MIMU technologies allowing the digital reconstruction of the movement.
Due to their massive spread in the sports context, particular attention is devoted to MIMUs integrating accelerometers, gyroscopes, and magnetic sensors. Their working principles and a battery of tests useful for their metrological characterization, as well as their calibration refinement process, are given. Sensor characteristics and good-practice procedures of relevance in the sport context are also detailed. General indications on how to extract the main biomechanical kinematic parameters contributing to objective performance monitoring/evaluation or to musculoskeletal injury assessment are provided either using sensor signals directly (temporal parameters, phase segmentation and angular velocity or linear acceleration) or through computation/modelling (3D absolute or relative orientation, namely joint kinematics, or the linear velocity or position). Thereafter, a detailed analysis of joint angles, body positions, and biomechanical patterns during sporting activities is enabled, allowing the definition of key performance indicators according to ad hoc technical analyses. Finally, running, being the sports activity that has undergone the most extensive research and enjoys the highest level of popularity, has been selected as the prime example for in-field analysis of signal processing and feature extraction. The attention is focused on the identification and the biomechanical comparison of different foot strike patterns due to their possible close relationship with running-related injuries
Comparison of regression models for interdistance estimate between two BLE devices based on RSSI
No full textElbow joint kinematics during cricket bowling using magneto-inertial sensors: A feasibility study
No full textMagnetic and inertial measurement units (MIMUs) may provide an accessible, three-dimensional, in-field alternative to laboratory-restricted marker-based motion capture. Existing upper limb MIMU models have predominantly been validated with low-velocity motion and their suitability for use with sport-based movements remains relatively untested. We propose a MIMU system approach to enable the estimation of anatomically meaningful and participant-specific elbow kinematics with considerations for use with cricket bowling. A novel standardised elbow reference posture of 90 degrees flexion and 0 deg pronation, and functional definition of elbow joint axes of rotation calibrated the MIMU method model before it was validated across three experiments: (1) simple elbow rotations with a mechanical linkage; (2) low-velocity elbow rotations in human participants; and (3) low-medium velocity sport-based movements in human participants. The proposed MIMU method demonstrated high elbow kinematic measurement agreement when compared with a criterion measure across all three conditions. However, during experiment 3, sensor components neared their measurement capacity and the MIMU method elbow flexion measurement variability increased. We conclude that the proposed MIMU method can estimate anatomically referenced, participant-specific joint angles, however, the hardware specifications of currently available systems may limit application in high-velocity/acceleration situations, preventing the measurement of cricket bowling in-field for now
Muscle coordination strategies during Functional Reach across multiple directions in healthy individuals
No full textPurpose. Understanding the neuromuscular strategies underlying postural stability is crucial for evaluating motor control and balance. This study examines muscle coordination during several variations of the Functional Reach (FR)—unilateral Functional Reach (uniFR), bilateral Functional Reach (biFR), and Lateral Reach (LR)—in healthy young adults. This study aims to establish a reference baseline for these tasks and assess whether fundamental motor control strategies are preserved across FR variations, despite distinct biomechanical demands and directional stability components. Methods. Seventeen healthy young adults performed ten repetitions for each FR task. Muscle synergies were derived using non-negative matrix factorization on surface electromyography (EMG) data recorded from eight muscles on each side of the body. Results. Results revealed that fewer synergies were required for anterior-posterior stability (uniFR and biFR), while medial-lateral control entailed in LR required an additional synergy. Despite the directional tuning of muscle contributions, both anterior-posterior and medial-lateral balance control relied on similar underlying motor functions, thus engaging the same muscle synergies in varying combinations. Furthermore, a greater similarity in muscle synergy structure and robustness was observed between uniFR and biFR compared to LR, suggesting a shared neural control strategy. Moreover, the LR task exhibited higher variability, reflecting a more complex and less standardized motor control process. Conclusion. Our findings indicate that similar motor functions are recruited across different balance tasks, with directionally tuned muscle synergies. This offers a deeper insight into the muscle coordination strategies during reaching tasks, providing a novel framework for evaluating the effects of aging or pathological conditions on neuromuscular control
A functional calibration protocol for ankle plantar-dorsiflexion estimate using magnetic and inertial measurement units: Repeatability and reliability assessment
Get PDFThe ankle joint complex presents a tangled functional anatomy, which understanding is fundamental to effectively estimate its kinematics on the sagittal plane. Protocols based on the use of magnetic and inertial measurement units (MIMUs) currently do not take in due account this factor. To this aim, a joint coordinate system for the ankle joint complex is proposed, along with a protocol to perform its anatomical calibration using MIMUs, consisting in a combination of anatomical functional calibrations of the tibiotalar axis and static acquisitions. Protocol repeatability and reliability were tested according to the metrics proposed in Schwartz et al. (2004) involving three different operators performing the protocol three times on ten participants, undergoing instrumented gait analysis through both stereophotogrammetry and MIMUs. Instrumental reliability was evaluated comparing the MIMU-derived kinematic traces with the stereophotogrammetric ones, obtained with the same protocol, through the linear fit method. A total of 270 gait cycles were considered. Results showed that the protocol was repeatable and reliable for what concerned the operators (0.4 +/- 0.4 deg and 0.8 +/- 0.5 deg, respectively). Instrumental reliability analysis showed a mean RMSD of 3.0 +/- 1.3 deg, a mean offset of 9.4 +/- 8.4 deg and a mean linear relationship strength of R2 = 0.88 +/- 0.08. With due caution, the protocol can be considered both repeatable and reliable. Further studies should pay attention to the other ankle degrees of freedom as well as on the angular convention to compute them
Editorial: Highlights in sports science, technology and engineering 2021/22
No full textNo abstract available
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