The Effect of Partial Sleep Deprivation on Ground Reaction Force Components Before and After Fatigue

Background: The combined effects of sleep deprivation and fatigue may increase the risk of injury. Analyzing ground reaction force (GRF) components during activities such as cutting maneuvers provides valuable insights into musculoskeletal function. This study aimed to investigate the effect of partial sleep deprivation on GRF components before and after fatigue.Methods: This semi-experimental study included 14 young women who were evaluated twice, with a 5-day interval between sessions. During the pre-test, participants had full sleep, whereas during the post-test, they experienced partial sleep deprivation (4 hours of sleep at the beginning of the night). In each session, participants performed five attempts without fatigue and three attempts under fatigue. GRF components were measured using a Kistler force plate under all conditions.Results: At the heel contact phase (FZ1), both fatigue (P = 0.012) and fatigue combined with partial sleep deprivation (P = 0.025) significantly reduced the time to reach peak vertical GRF. Moreover, the interaction between fatigue and partial sleep deprivation resulted in a significant decrease in vertical loading rate (P = 0.019). However, no significant differences were observed in the peak GRF or impulse across conditions.Conclusion: The interaction of fatigue and partial sleep deprivation appears to exacerbate injury risk factors, particularly by increasing loading rates and reducing the time to reach peak GRF.