Introduction: Fatigue in aspect of physiology cause the weakness of body function in other to ‎produce power and in term of bio mechanics affects body position in static and dynamic balance ‎during sports activity. Sidestep cutting movements are common in many sports. Sidestep cutting ‎movements commonly used for kinematic and kinetic assessment of knee joint in field of anterior ‎crucial ligament injuries risk factor. The purpose of this study was ‏determine the effect of ‎fatigue on center of pressure to center of mass changes during side ward cutting in the professional ‎athletes.‎
Methodology: 12 Professional athletes (age 24±3 years old, and weight 74.1±19.2 kg) participated ‎in this study. They all had at least 5 years training experience with provincial and national ‎championships. Force plate (Bert, Made in USA) was required to collect the center of pressure ‎data with 500 Hz sample rate. Center of pressure changes to the center of mass was calculated in ‎medial- lateral and anterior-posterior direction by‏ ‏winter inverted pendulum formula. Each subject did ‎‎3 times side ward cutting maneuver with dominant and none dominant limb in normal and fatigue ‎situation (Bruce Protocol up to failure).The normality of data was checked by Kolmogorov- ‎Smirnov normality measure samples and data were analyzed with pair sample t-test to compare ‎variables before and after fatigue, with a significance level of (P≤0.05).‎
Results: Results indicated that fatigue had insignificant effect on center of pressure to the center of ‎mass Medial- lateral direction in none ‏dominant limb (P=0.005). nonetheless there was no significant ‎difference in the dominant limb (P=0.074). also effect of fatigue on center of pressure to the center ‎of mass anterior- posterior direction in both dominant and none dominant limb were significant ‏‎(‎P=000 and ‏P=0.046 respectively).‎
Discussion: According to results of present study, we can conclude that fatigue can effect on ‎center of pressure to center of mass during side ward cutting that led to increasing the risk of lower ‎extremity injuries.‎