Comparison of the Effects of Extremity Fatigue and Mental Fatigue on Balance, Proprioception and Reaction Time

This study aims to understand how different types of fatigue affect balance and reaction time, proprioception, and fine motor in healthy young adults. Fatigue is a common experience in daily life and can arise from physical activity or prolonged mental effort. The study seeks to determine whether fatigue of the upper body, lower body, or mental fatigue from cognitively demanding tasks can negatively affect balance and reaction time, proprioception, and fine motor abilities.

To examine this, participants will undergo controlled fatigue protocols designed to tire specific parts of the body or the mind. the Upper body fatigue will be induced through repeated maximal push-up sets performed until the participant can no longer maintain proper form. Lower body fatigue will be created through repeated maximal 1-minute squat jump sets, with participants touching a low box to ensure standardized depth and proper movement. Mental fatigue will be induced using a 20-minute computer-based cognitive task that alternates between the 2-back working memory task and the numerical Stroop task. These tasks are designed to require continuous attention, mental effort, and inhibitory control. Each type of fatigue will be induced independently, and participants' performance will be measured before and after each fatigue protocol.

Following fatigue induction, participants will complete a series of tests designed to assess balance and reaction time, proprioception, and fine motor abilities. This includes both static and dynamic postural tasks, as well as reaction time and proprioceptive accuracy assessments. By evaluating these measures before and after fatigue, the study will determine how different forms of physical and mental fatigue impact postural stability, sensory processing, and precise motor control.

The study addresses the question: "Do upper body fatigue, lower body fatigue, or mental fatigue reduce balance and reaction time, proprioception, and fine motor performance in healthy young adults?" The hypothesis is that each form of fatigue upper body, lower body, or mental-will meaningfully impair balance and reaction time, proprioception, and fine motor performance compared to non-fatigued conditions.