Background Although the hamstring muscle group gets loaded during the kicking motion, the effect of a previous hamstring injury on the kicking skill has not been studied in detail.

Objective To the study the effect of a previous hamstring injury on the kicking technique, and how gender and limb dominance influences the same.

Design Observational study. Participants were required to kick the ball into a target 7 m away using a four step run-up. Five valid kicks were taken from the dominant and non-dominant limb each.

Setting Laboratory conditions on FIFA approved artificial turf, with a three-dimensional Vicon motion capture system at 200Hz and a Kistler force platform at 1000Hz. with participants belonging to Spanish First (women) and Second (men) Division teams.

Participants 45 professional soccer players (females=26, males=19) who belonged to clubs that had the same number of training sessions and matches per week.

Main Outcome Measurements Ball velocities, kinematic and kinetic data for the hip and knee of the kicking leg in the sagittal plane, and the reaction forces for the ground and the support leg. 3-way ANOVA was used to compare the data.

Results Previously injured female athletes had a lower peak hip velocity in the dominant limb kicks; and a smaller knee flexion angle, and a lower hip flexion velocity in the non-dominant limb kicks.

Conclusions Kicking technique is affected by a previous hamstring injury in females especially in phases where the hamstring muscles are the most active. Differences in male soccer players were not seen. Thus these injuries must be treated differently in male and female soccer players, and whether the injury occurred in the dominant or non-dominant limb. An additional study with a greater number of previously injured athletes would be necessary to provide conclusive results.