One of the factors affecting jump-landing patterns is fatigue. Fatigue is an inevitable component of physical

activity, hence the aim of the present study was to investigate the effect of functional fatigue on landing

mechanics through Landing Error Scoring System (LESS).Fourteen male college students with a mean age of

22±2 years, weight of 68.3±7.2 kg and height of 174±4 were randomly divided into two groups: experimental and

control. Effect of independent variable, fatigue, due to activities resembling athletic training or competition (6-

stations functional fatigue protocol) on dependent variable, landing mechanics, through pre test-post test was

investigated. The independent t-tests and non-parametric U-Mann Whitney test was used for statistical analysis

of data (P < 0.05). The results of the present study indicated the relationship between fatigue and attenuation of

landing mechanics (P=0.02), and therefore an increase in injury risk. Also it was shown that the effect of fatigue

on decreasing knee flexion angle at initial contact was significant (P=0.022). With regard to the results, it can be

concluded that functional fatigue induced by physical activities can alter landing mechanics, and increase loading

of lower extremity joints, particularly the knee. So the risk of injury in these joints may be increased.