Objective: The purpose of this study was to investigate knee alignment and foot structure in futsal players with and without hamstring shortness.
Methods: In this descriptive - comparative study, 30 men athlete (18- 25 years) were recruited. They were assigned into two groups of 15 subjects with and without hamstring shortness. The hamstring shortness, knee and foot alignment were respectively measured by the goniometer, the ruler and caliper. After checking the normality of the data, (with Shapiro-Wilk test) independent samples t-test, were used to analyze of data at a significance level of P < 0.05.
Results: The findings indicate that there is a significant difference between the navicular drop in both groups, with and without hamstring shortness with the difference being lower in athletes with hamstring shortness (P= 0.002); but there is not any significant difference between the distances between Femur Condylar in both groups (P> 0.05).

Conclusion: It seems that, navicular drop is not common among athletes with hamstring shortness.