Goal-Oriented Optimization of Dynamic Simulations to Find a Balance between Performance Enhancement and Injury Prevention during Volleyball Spiking.

Dhruv Gupta,Jody L Jensen,Cyril J Donnelly,Jeffrey A Reinbolt

doi:10.3390/life11070598

Abstract

Performance enhancement and injury prevention are often perceived as opposite sides of a coin, where focusing on improvements of one leads to detriment of the other. In this study, we used physics-based simulations with novel optimization methods to find participant-specific, whole-body mechanics of volleyball spiking that enhances performance (the peak height of the hitting hand and its forward velocity) while minimizing injury risk. For the volleyball spiking motion, the shoulder is the most common injury site because of the high mechanical loads that are most pronounced during the follow-through phase of the movement. We analyzed 104 and 209 spiking trials across 13 participants for the power and follow-through phases, respectively. During the power phase, simulations increased (p < 0.025) the peak height of the hitting wrist by 1% and increased (p < 0.025) the forward wrist velocity by 25%, without increasing peak shoulder joint torques, by increasing the lower-limb forward swing (i.e., hip flexion, knee extension). During the follow-through phase, simulations decreased (p < 0.025) peak shoulder joint torques by 75% elicited by synergistic rotation of the trunk along the pathway of the hitting arm. Our results show that performance enhancement and injury prevention are not mutually exclusive and may both be improved simultaneously, potentially leading to better-performing and injury-free athletes.

Highlights

Enhancing arm swing performance without increasing injury risk during a volleyball spike are two pillars supporting the long-term success of any volleyball attacker
The general kinematic pattern used to enhance performance without increasing the risk of shoulder injury can be described as the forward swinging of the legs with increased hip flexion and knee extension
Five critical coordinates across at least 40% of the participants were observed (Figure 4b). These results show that the trunk rotation with the hitting arm is the primary kinematic pattern that reduces the peak shoulder torques

Summary

Introduction

Enhancing arm swing performance without increasing injury risk during a volleyball spike are two pillars supporting the long-term success of any volleyball attacker. Achieving a balance between performance and injury risk is considered as a difficult training task, as increased performance is coupled with kinematics that are known to underpin musculoskeletal injuries. Kinematic changes are non-linearly associated with both performance [4,5,6] and shoulder injury risk [6,7,8,9,10] during the volleyball spiking motion. For this reason, optimal kinematics may potentially increase performance and decrease injury risk simultaneously [6]. The downstream effects of identifying optimal kinematics could significantly advance the field of athletic training and rehabilitation, and potentially lead to longer injury free careers at a high level of performance for the athletes

Methods

Results

Conclusion