Component of Ground Reaction Forces in People with Ankle Sprain Compared with Healthy Subjects During Running

Functional ankle sprain is a common injury in different sports. Study of Ground Reaction Forces in different physical activity is associated with the risk of lower extremity injury and has a clinical importance. The objectives of this study were to analyze the GRF, and loading rate during running in ankle sprain compared with healthy subjects.

In this study, 10 healthy men and 10 soccer player with ankle sprain participated. Using two adjacent Kistler force plates (1000Hz) GRF during stance phase of running was measured. Then, maximum GRF, impulse, and loading rate, were obtained. MANOVA was used to analyze the data (α=0.05).

The results showed that there is a significant difference between two groups in ground reaction force of Fz1and Fz2 (p=0.01, p=0.01). On the other hand, there was a significant difference between the two groups in time to peak of components in Fz3 and Fx2 directions (p=0.02, p=0.004). Also, there was a significant difference between the two groups in time to peak of components in Fy1 and Fy2 directions (p=0.04, p=0.04).  The experimental group showed a higher loading rate than the control group (p=0.01).

The results showed that the values of initial reaction force and loading rate in the experimental group were higher than the control group. It seem less foot adaptability increases the loading rate in the experimental group. Since these forces are exacerbating the types of structural damage, therefore, therapists should pay particular attention to reducing these forces by modifying the motor strategy, strengthening the muscles and, even in some cases, prescribing a medical insole.