Initial Recommendations for Virtual Reality in Mental Health Care from the American Medical Extended Reality Association.

Baseball bat swing is a high-speed, explosive movement involving a kinetic chain, which requires the efficient transmission of force and energy among the lower extremities, pelvis, torso, upper extremities, and the bat itself (). Key factors influencing swing performance include: lower body force generation and the utilization of ground reaction force (GRF), parameters such as hip-shoulder separation, counter-movement, backswing, torso rotation speed, and the timing of the upper extremities and wrists (). At the outcome level, commonly used assessment metrics include bat velocity, exit velocity, and time to contact (). In the field of sports medicine and performance optimization, effective dynamic warm-ups can improve muscle blood flow, enhance nerve conduction and muscle contraction speed, increase joint range of motion (ROM), and reduce injury risk, thereby creating optimal neuromuscular conditions for high-speed swinging (). In recent years, Whole-Body Vibration (WBV) training has been widely applied in strength and conditioning (). WBV can reinforce reflexes during muscle contraction, inducing the Tonic Vibration Reflex (TVR), which subsequently affects muscle spindle proprioception and alters the length regulation and contraction speed of skeletal muscle fibers (). Previous studies have shown that implementing WBV with stable vibration intensity and protocols can promote muscle adaptation and enhance multiple neuromuscular and physical fitness indicators, including muscle strength and explosiveness, flexibility, body composition, and Delayed Onset Muscle Soreness (DOMS) (). Therefore, incorporating vibration stimulation into a training program helps optimize muscle contraction characteristics and motor output. The positive short-term effects of WBV on lower limb explosiveness have been validated by multiple experiments; for instance, protocols using a frequency of 30 Hz are commonly seen in interventions aimed at enhancing explosiveness. Under various combinations of frequencies (30 to 50 Hz) and amplitudes (2 to 5 mm), the immediate effects of WBV are typically most pronounced immediately after the intervention up to 1 min, and may attenuate after approximately 5 min. All of the above suggest that an appropriate WBV protocol can serve as an acute activation method before sport-specific technical training (; ; ). Furthermore, as a complex kinetic chain movement, baseball bat swing performance is not only dependent on the generation of lower limb explosiveness and ground reaction force (GRF) but also relies on the efficient transmission and synergistic output of energy between the torso and upper extremities (). However, current empirical evidence regarding the inclusion of Whole-Body Vibration (WBV) training in baseball bat swing protocols and the examination of its training effects on improving key technical parameters and kinetic chain efficiency remains relatively limited. Existing research predominantly focuses on general physical fitness items such as jumping, squatting, or lower body strength, with a relative lack of systematic discussion on utilizing WBV as a specific intervention to enhance baseball-specific technical performance (). In addition, the existing literature review is often not sufficiently systematic in explaining the potential application mechanisms of whole-body vibration training (WBV) for baseball batting (e.g., neuromuscular activation, enhanced proprioceptive input, post-activation potentiation–related effects, and improved inter-segmental coordination), which makes it difficult to establish a clear mechanistic pathway from (WBV) stimulus to batting-specific outcomes (; ; ; ; ; ; ; ; ; ; ; ). Moreover, the rationale for selecting 30% 1RM and 50% 1RM as external load gradients in WBV-based protocols has not been clearly articulated in prior work, and the theoretical basis for these specific intensities (e.g., balancing neuromuscular facilitation versus movement quality/fatigue, or aligning with commonly used “light-to-moderate” resistance ranges for power-oriented activation) remains insufficiently justified (; ; ; ; ; ; ; ; ; ; ; ).