Background and Aim: core stability is defined as the ability of muscles to control and maintain the position of the trunk and its movement on the pelvis and lower limbs in order to produce, transfer force and move to the extremities of the body during physical activities. Weakness in central stability leads to impaired energy transfer and reduced sports performance. Also, weakness in the central muscles is related to lower limb injuries. Investigating the effect of central body muscle fatigue on the performance of other organs can provide useful information about the role of central body stability in sports performance. Considering the importance of central stability in sports performance, the purpose of this research is to investigate the effect of central body muscle fatigue on upper limb performance and functional motor screening test scores of male athletes.
Methods: A semi-experimental research approach was used, involving 40 male students aged 19 to 26, selected purposefully and based on availability meeting the inclusion criteria. To assess upper limb function, two tests focusing on upper body and upper limb stability in a closed movement chain were employed. The functional movement screening test was also used to measure movement function before and after inducing fatigue. Data analysis was conducted using Wilcoxon and T-paired statistical tests (p<0.05).
Results: The results from the Wilcoxon test indicated that after the fatigue protocol, individuals exhibited significantly poorer performance in deep squats (P=0.001), In-Line Lunge (P=0.001), Hurdle Step (P=0.001), trunk rotatory stability (P=0.001), and the total scores of the movement screening test (P=0.001). However, there was no significant difference in other subtests between the two measurement stages (P<0.05). The paired sample t-test also revealed that individuals performed poorer in the upper quarter Y balance test (P=0.001) and closed kinetic chain upper extremity stability test (P=0.001) after the fatigue protocol compared to before.
Conclusion: The study shows that core muscle fatigue significantly decreases scores in upper functional tests and motor screening, suggesting the need for endurance exercises targeting core muscles to improve fatigue resistance during prolonged activities.