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This study aimed to quantify and compare the upper limb angular kinematics and its contributions to the racket head speed between the cross-court (CC) and inside-out (IO) attacking tennis forehand of elite tennis players in a competitive environment. A new approach was used to study the forehand drive with mini-inertial sensors of motion capture to record the kinematic data. Six strokes in each direction per participant (72 shots in total) were chosen for analysis. Upper limb kinematics were calculated in the Visual 3D platform (Visual 3D Professional V5.01.21, C-motion, Germantown, MD, USA). The method used to calculate the upper limb’s contributions was performed with MATLAB software and used the segment’s (upper arm, forearm and hand) angular velocities and their respective displacement vectors obtained through the inertial sensors. Upper limb kinematics demonstrated a higher shoulder rotation in the IO direction with significant differences at the end of the backswing, which could be a key factor in distinguishing the two directions of the shot. Results also demonstrated that the horizontal flexion of the upper arm (around the shoulder joint) was primarily responsible for the racket velocity in the anteroposterior direction (48.1% CC and 45.2% IO), followed by the extension of the forearm (around the elbow joint) (17.3% CC and 20.9% IO) and the internal rotation of the upper arm (around the shoulder joint) (15.6% CC and 14.2% IO). No significant differences were shown in the contributions of upper limbs to the racket head velocity between the two directions of the shot. Tennis coaches and players should develop a specific training programme to perform higher angular velocities in these specific joint rotations.

There are advantages in using inertial measurement unit systems (IMUS) for biomechanical analysis when compared to 2D/3D video-based analysis. The main advantage is the ability to analyze movement in the natural performance environment, preserving the ecological validity of the task. Coaches can access accurate and detailed data in real time and use it to optimize feedback and performance. Efforts are needed to validate the accuracy of IMUS. We assess the accuracy of the IMUS Xsens MVN Link system using an optoelectronic system (OS) as a reference when measuring 3D joint angles during the gymnastics round-off back handspring technique. We collected movement kinematics from 10 participants. The coefficient of multiple correlation (CMC) results showed very good and excellent values for the majority of the joint angles, except for neck flexion/extension (F/E). Root mean square errors (RMSE) were below/near 10°, with slightly higher values for shoulder (12.571°), ankle (11.068°), thorax-thigh F/E (21.416°), and thorax–thigh internal/external rotation (I/E) (16.312°). Significant SPM-1D {t} differences for thorax–thigh abduction/adduction (A/A), neck, thorax–thigh, knee, shoulder and ankle F/E were demonstrated during small temporal periods. Our findings suggest that the Xsens MVN Link system provides valid data that can be used to provide feedback in training.

Embodying Sound is a performing art project that integrates dance, music and digital technology, it explores a real-time sonification of human motion, captured by inertial sensors, using the XSens system. First and foremost, it is not a demonstration of technical virtuosity, but an attempt to put technology at the service of imagination and creativity. In a world dominated by computation-tending to a dystopic future of "artificial intelligences" [1], we tend to forget that present-day machines cannot really think or feel; Computers do not have purposes, do not love or understand reality the way a living organism does [2]. In this presentation, we explore how technology can act as a mediator between dance and music. The quest of this performative process is to investigate the sound signature of the body. Here we discuss how such phenomenological experience might challenge self-consciousness and the perception of identity. Furthermore, within a more general approach, we question how does this artistic and technological interaction stimulate the expansion of artistic expression, which might result in new aesthetics.

In the last two decades, graffiti has established itself as a visual element of the metropolis in Brazil. It became part of the urban routine, and in a dispute for space has been struggling for public visibility with building colors, traffic signs and other elements of urban communicability. And it does so by changing its intent and original essence. This paper seeks to document the trajectory of graffiti from the mid 1960s to the conclusion of the research, in 2011, following its transformation "from subversive to acclaimed". By means of a visual narrative marked by a selection of 400 photographs taken by the researcher, the city of São Paulo is emphasized, where graffiti is attracting worldwide attention and not only among supporters, sympathizers and specialized publishers. Graffiti has been an interesting field of study for art critics, anthropologists, semiologists, and scholars in general, but the greatest impact of this street art is on the urban scene.