The assessment of movement demands and neuromuscular fatigue in female softball players

Softball has experienced an increase in worldwide popularity over the last 15 years, and it is expected to rise following the reinstatement of softball as an Olympic sport in 2021. Previous softball research has primarily focused on the biomechanical characteristics of its athletes. However, there is a current lack of research concerning the movement demands occurring in gameplay and the development of neuromuscular fatigue in softball players during sportspecific movements, training sessions, or in competition play. Prior research has demonstrated that a majority of power generated during a bat swing or overhand throw comes from the lower body, with the hip musculature playing an essential role in stabilisation and kinetic energy transmission. Understanding the development of neuromuscular fatigue, particularly in the hip musculature of softball athletes, will allow coaches and sport scientists to optimise training sessions, athlete monitoring techniques, and recovery methods. Accordingly, the overall aims of this thesis were to 1) describe the movement demands of female softball players during defensive and offensive gameplay, with a focus on the frequency and duration of movements occurring and differences between positional groups; 2) determine the reliability of the ForceFrame Hip Strength Testing System in assessing hip and shoulder strength of female softball players unaccustomed to isolated joint isometric measures; 3) assess changes in isometric hip strength in female softball players caused by a repeated batting protocol; and 4) compare changes in isometric strength of female softball players in training and game settings. The outcomes of this thesis will help to establish a description of the movement demands of softball games, which may optimise future softball training and recovery methods. Additionally, data gathered in this thesis will provide a solid foundation for conceptualising neuromuscular fatigue in softball players. These results will thus allow for a greater understanding of athlete preparation. Study one determined that softball is primarily composed of low intensity activities, like standing or walking, with intermittent periods of high intensity activity (e.g. sprinting, bat swings, high intensity throws). The cumulative effect of these high intensity activities across game durations of two hours or greater, compact tournament schedules and environmental factors may amplify neuromuscular fatigue. Study two concluded that the ForceFrame was a reliable tool in assessing hip and shoulder isometric strength in female diamond-sport athletes, potentially providing sport scientists with a suitable alternative to handheld dynamometers in field-based isometric testing. Study three documented changes in electromyographic amplitude and median frequency, isometric hip strength, and batted ball velocity of female softball players during a repeated batting protocol. Results indicate repeated batting can lead to neuromuscular fatigue and underscores the importance of routine monitoring of softball players in settings with limited recovery. Results of study four demonstrated significant levels of fatigue following softball training and gameplay, as well as evidence of cumulative fatigue in softball players following several games during a multi-day tournament. The results of this study provide the groundwork for determining an appropriate balance between competition-level training and adequate recovery.

Grantor dc:publisher

Edith Cowan University, Research Online, Perth, Western Australia

Year dc:date

2022

Author dc:creator

• Cardwell, Kathryn

• Softball
• isometric strength
• time-motion analysis
• neuromuscular fatigue
• reliability
• Medicine and Health Sciences
• Sports Sciences

Repository record dc:identifier

https://ro.ecu.edu.au/theses/2501

OAI identifier oai:identifier

oai:ro.ecu.edu.au:theses-3503