Goalball is the most popular sport among visually impaired individuals, who highly prioritize engagement in physical activities [
1,
2]. This team sport not only fosters social interaction but also enhances physical fitness and well-being [
3]. Goalball is played with an eye band and a ball which has a buzzer and consists of two stages: defense and attack. During gameplay, all players, regardless of their visual acuity, wear eye band and rely on auditory cues to perceive the ball’s direction and proximity. In the defensive phase, players demonstrate agility by manoeuvring on the field to thwart the opposing team’s attempts to score. Upon gaining possession of the ball, a player transitions to the attaching phase, employing various throwing techniques. These techniques include straight throws without turning, as a bowling shot or rotational throws (360-degree arm rotation) resembling discus throws. In Goalball, ball velocity significantly influences the success rate of scoring attempts, with spinning motions (360-degree arm rotation) often preferred over traditional throws (without turning) for their ability to generate faster and more forceful shots [
4]. The activation levels of certain muscles, such as the flexor and extensor muscles in the arm and hand, directly influence the speed and trajectory of the thrown ball [
5,
6]. In spinning throws, for example, the coordination and synchronization of forearm muscles are essential for executing the rotational movement effectively. Higher activation levels in specific muscle groups, such as the flexor muscles, may contribute to generating greater torque and rotational force, resulting in increased ball velocity. Conversely, in traditional throws, where linear force is heavily applied, the activation patterns of forearm muscles may differ, with emphasis on stabilizing and propelling the ball in a straight trajectory. Therefore, understanding the activation patterns of forearm muscles is crucial for assessing ball velocity, particularly in different throwing techniques such as spinning and traditional throws in sports like Goalball. Surface EMG technology contributes to the assessment and improvement of athletic performance in sports science by providing a non-invasive and simple method for measuring forearm muscle activity which plays a significant role in generating the force required for ball propulsion during throwing movements muscle [
7]. Identifying muscle activation patterns associated with best throwing performance can inform training strategies aimed at improving technique and enhancing ball velocity in sports-related movements. For instance, research in baseball pitching has utilized EMG technology to investigate the role of forearm muscle activation in pitch velocity and accuracy [
8]. Physiological studies show that the muscles in the distal and proximal extremities work synergistically to create a movement pattern [
9]. Although it is important to evaluate muscle activity during shooting to improve the athlete’s shooting performance and sports skills, it is also extremely important that the evaluation method is practical, accessible, and suitable for disability [
10]. The integration of surface EMG with other technologies, such as Bluetooth low energy for real-time data transmission, further enhances its potential for remote monitoring, rehabilitation, and diagnostic techniques. In particular, new state-art wearable EMG devices offer a practical and non-invasive means of assessing muscle activation during dynamic tasks such as throwing movements, by enabling real-time measurement and recording of muscle activity [
11]. Myo armbands, developed by Thalmic Labs as wearable and wireless EMG devices, offer dependable, robust, and low-cost EMG data, which allows humans to interact with computers. It has been used in various applications such as healthcare applications for people with disabilities with mobility problems, hearing-impaired people, multiple sclerosis, and children with motor impairment, upper-limb prostheses, controlling flying drones, robot movements or robotic prosthesis, gaming applications, virtual reality simulations, and human-computer interaction [
12‐
15]. However, its use in determining performance in sports is limited, in particular, in the throwing performance of Goalball players [
16]. To evaluate the relationship between forearm muscle (e.g., the flexors and extensors) activation and ball velocity in the Goalball, The Myo armband, with its capability to detect and interpret muscle activity, could potentially be used in sports performance analysis, including activities like handball or Goalball. It can provide useful information about muscle activation patterns and coordination during Goalball movements, and important factors in throwing performance [
17].
Despite the growing interest in sports biomechanics and adaptive sports, there remains a notable gap in the literature concerning the relationship between forearm muscle activation and ball velocity in Goalball players. While Goalball serves as a prominent sport for visually impaired individuals, limited empirical evidence exists to elucidate the electrophysiological mechanisms underlying best throwing performance in this population. Specifically, the deficiency lies in the absence of comprehensive studies that systematically investigate how variations in forearm muscle activation patterns influence ball velocity during Goalball throwing movements. Understanding the nuanced interactions between muscle activation, throwing technique, and performance outcomes is paramount for developing targeted training interventions aimed at enhancing the effectiveness and efficiency of Goalball players’ throwing mechanics. Furthermore, the lack of empirical research in this area impedes the development of evidence-based training strategies tailored to the unique biomechanical and physiological needs of visually impaired players. By addressing this research deficit, the current study seeks to fill a critical knowledge gap and contribute valuable insights to the field of sports biomechanics and adaptive sports.
Therefore, in this study, we aim to evaluate the electrophysiological performance of forearm muscles in different visual conditions and Goalball penalty throwing techniques using the Myo armband. We hypothesize that flexor muscle group activity will predominate over extensor muscle group activity during shooting performance. Additionally, we hypothesize that spinning throws will confer an advantage over traditional throwing in terms of ball velocity and biomechanics. Lastly, we anticipate that the use of an eye band will adversely affect throwing performance.