Aug 2026· Research on Biomedical Engineering· Vol 42· 0 citations· 25 references
TL;DR
The developed device met the objectives of the study, being able to monitor the balance in different difficulties, however, a longer period of volunteer testing is required to determine the effect of the device on long-term balance.
Abstract
The aim of this work was to develop a sensorized wobbleboard capable of changing its type of instability and quantifying the body stability through a dashboard and an exergame. The device was assembled using a wooden disc with load cells attached to it. At the bottom of the disc, three pieces of instability can be attached. In this study, two software applications were developed. The first, was a Dashboard capable of displaying the center of pressure (CoP) path. The other was a WobbleBall game whose goal is to keep the avatar inside a scoring ring whose radius is constantly reduced. To validate this study, two tests were performed, CoP and Volunteers tests. In the CoP test, a set of weights was placed in different positions on the device, and the CoP position calculated by the Dashboard was recorded. In the volunteers test, the balance was compared before and after a session of the WobbleBall game, using all three of the instability pieces developed. The CoP test results showed that the device can point the CoP position within the acceptable error. The result of the test with volunteers showed that there was no significant difference in balance before and after the game session. Additionally, participants achieved better results when playing the game under isolated anteroposterior and lateral instability, while poorer results were observed when playing without instability and with instability in both axes simultaneously. The developed device met the objectives of the study, being able to monitor the balance in different difficulties. However, a longer period of volunteer testing is required to determine the effect of the device on long-term balance.
Introduction The development of a low-cost system for analysis of the hammer throw technique is presented. The system is based on analyzing the information provided by off-the-shelf inertial measurement units (IMUs). Methods Five Spanish national-level hammer throwers (2 women, 3 men) performed 6 trials with homologated implements (4 kg for women, 7.26 kg for men) at the High-Performance Sports Centre (CAR) in Madrid during regular training sessions. The IMUs were positioned at three points on the thrower’s body: right instep, lumbar zone, and wrist. All IMU raw data (angular velocities, linear accelerations, and Euler angles) were processed and visualized using Matlab software to analyze and derive additional parameters. Results After analyzing the patterns of the raw data provided by the IMUs with professional coaches, algorithms for determining the duration of the single and double support phases for each turn were developed and described in the paper. These raw data also allow us to derive additional biomechanical parameters that help characterize the quality of the athlete’s throwing technique (wrist angular velocity and linear acceleration, pelvic tilt, horizontal azimuthal angles, arm elevation angles, and vertical foot acceleration). Validation against a VICON motion capture system showed excellent agreement for phase durations (ICC = 0.977) and angular displacements (ICC = 0.976). Discussion The data obtained using IMUs represent only a subset of the information that can be obtained from a hammer throw using current 3D photogrammetry techniques. However, as the hammer throw is a rotatory movement, a valuable information according to the literature can be obtained from IMUs at very low cost and without access to specialized high-performance centers or biomechanics laboratories. These findings demonstrate that an IMU-based framework constitutes a reliable low-cost solution for coaches and athletes who can benefit from this technology in their regular training sessions.
J. Sánchez-Moreno, D. Moreno-Salinas, Carlos Revuelta-Parra et al.· Frontiers in Bioengineering...· 0 citations
Trunk balance is essential for physical stability, but traditional assessment tools, such as force plates and 3D motion capture systems, can be inaccessible or unsafe for patients unable to stand. This study introduces a seated trunk balance training and assessment system that combines a tilting chair with an Inertial Measurement Unit (IMU). The system features a kinematic design that transmits the user's trunk movements to the chair's seat, allowing for quantitative measurement without the need for body-mounted sensors. A pilot study was conducted to evaluate technical feasibility by comparing a seat-mounted sensor (CS-IMU) with a reference sensor (T12-IMU) attached to the T12 vertebra. Assessment items included Range of Motion (RoM), rotation accuracy, and agility. Results indicated a very high correlation for lateral bending (r = 0.958) and rotation phase angle (r = 0.990), while flexion/extension showed a moderate correlation (r = 0.691). Additionally, agility tasks demonstrated consistent results in the lateral direction (r = 0.806). These findings suggest that the proposed system can effectively quantify multi-dimensional trunk movements in a seated position, making it a valuable tool for high-risk populations, such as patients recovering from acute stroke or spinal cord injuries.
Jeong-Woo Seo, Yeong-Gi Kim· Journal of the Korean Societ...· 0 citations
Posture plays a significant role in the physical health of musicians in general, especially those who play string instruments, such as cellists, for whom the interaction between the trunk, upper limbs, and instrument support requires proper alignment. This study aims to investigate the influence of different chair heights on the posture of a cellist during the performance of a musical scale, using biomechanical analysis through motion capture. One participant who was a beginner on the instrument performed the task under four conditions: seated on the same chair adjusted to heights of 42 cm (23.1% of the participant’s height), 48 cm (26.4%), and 54 cm (29.7%), and in a near-standing position. Joint angles of the shoulder (the primary variable) were analyzed, as well as those of the pelvis and the elbow of the arm holding the bow (secondary variables). No changes in the height of the endpin were considered; that is, it was not adjusted and remained at the same setting for all participant positions. The results showed that chair height has a direct effect on shoulder flexion, with lower mean values observed at the 48 cm chair height and greater demands in the near-standing posture. Thus, within the scope and limitations of this study, it was concluded that chair height can, to some extent, alter the ideal posture of the cellist, impacting comfort, stability, and biomechanical efficiency. Furthermore, the importance of individualized furniture adjustments for musicians is emphasized.
Introduction: Although timbersports are increasing in popularity, much is unknown about the optimal technique to improve accuracy and performance of these sports. The purpose of this study was to investigate biomechanical strategies used in an axe throwing task.
Methods: Participants were recruited from a college timbersports team. Inertial measurement sensors placed on the upper body were used to measure joint angles during three trials of axe throwing. Functional range of motion and release angle in the sagittal plane were computed from the shoulder, elbow, wrist and trunk and compared to the axe’s distance to center, position on the target and handle position.
Results: Shoulder functional range of motion was significantly correlated with distance to center (r = .85, p = .004). and significantly predicted distance to center. Males released the axe with a more extended elbow (Mean = 14.1° + 8.1) than females (M = 31.5° + 9.9). However, this difference may be related to height differences rather than sex differences. Height of the thrower had a significant impact on the correlation of elbow and wrist movement to throwing outcomes.
Conclusions: Shoulder functional range of motion is a significant predictor of axe throwing accuracy. The height of the thrower should be considered when coaching axe throwers on appropriate strategies to improve axe throwing performance.
Amber M. Chelette, J. Stovall, Iris-Sol Santana et al.· Research in Strength and Per...· 0 citations
Upper-limb exoskeletons mounted on wheelchairs represent a promising solution for paraplegic patients, as they can reduce shoulder overload while enabling the performance of daily activities. This paper presents the modeling, functional design, and prototyping of a novel five-degree-of-freedom (5-DoF) upper-limb exoskeleton, developed with a strong emphasis on lightness and biomechanical compatibility to ensure low-effort use by patients. The proposed mechanical architecture is specifically designed to facilitate seamless integration with a wheelchair. Kinematic modeling is performed using Denavit-Hartenberg (DH) parameters and is experimentally validated through motion capture data obtained with an OptiTrack system. The results demonstrate that the joint ranges closely match physiological human motion and confirm the validity of the proposed kinematic model. This work establishes a solid baseline for the development of intelligent control strategies in future research, in which motorization will be introduced to actuate at least one degree of freedom of the system, specifically shoulder abduction.
L. Carbonari, Serenella Terlizzi, Federico Neri et al.· 2026 IEEE/ASME International...· 0 citations
This paper presents the design, development, and preliminary proof-of-concept validation of a compact robotic knee exoskeleton for lower-limb assistive application. The proposed system addresses the trade-off between biomechanical compatibility, structural compactness, and reduced mechanical complexity through a lightweight single-degree-of-freedom architecture incorporating a polycentric knee mechanism. The exoskeleton integrates a compact brushless motor unit directly into the wearable structure, combined with a high-ratio transmission system based on a Capstan-driven architecture and a gear-reduction stage, enabling compact actuation. In addition, an embedded sensing system based on magnetic encoders and inertial measurement units was integrated to enable onboard monitoring of joint kinematics during movement execution. Experimental validation was conducted during representative lower-limb tasks, including walking and sit-to-stand movements. Joint kinematics were analyzed through gait-cycle and task-cycle normalization procedures to evaluate the consistency and repeatability of the measured motion. In addition, a comparative gait analysis was performed to assess the biomechanical impact of the proposed polycentric mechanism during walking by comparing natural walking, polycentric-joint walking, and walking with a locked single-axis configuration. The experimental results demonstrate the functional feasibility of the proposed design and provide preliminary evidence of repeatable kinematic behavior during representative lower-limb tasks. Furthermore, the comparative analysis showed that the polycentric configuration better preserved gait symmetry and reduced compensatory adaptations compared with the locked single-axis configuration. These results highlight the potential of reduced-complexity polycentric architectures for developing compact, wearable knee exoskeletons with improved biomechanical compatibility.
Carla Finocchiaro, Giuseppe Sutera, D. Guastella et al.· Actuators· 0 citations
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