3D-Biomechanical Analysis of the Soccer Kick

1. 3D-Biomechanical Analysis of the Soccer Kick

2. Introduction • We chose to look at the biomechanics of the soccer kick • Two different kicks were looked at: • The straight kick • The sweep kick

3. Purpose & Objectives • We sought to look at the angular velocities, moments and powers at the hip and knee joints • The different contributions of the specific muscle groups for each of the kicks

4. Literature reviewed • Majority of previous studies have focused on the kinematics • Very few studies have performed 3-D analysis, those that have did kinematics only • Previous studies found: • hip flexion followed by hip extension moment produces knee extension, not the knee extensors • Knee flexors are active during knee extension to prevent hyperextension (study by D.G.E. Robertson, C. Fernando, M. Hart & F. Beaulieu)

5. Methods • The motion was captured using the Vicon® motion capture system • 5 infrared cameras were used at a sampling rate of 100Hz. The data was filtered using a Woltring GCV filter • A 28-marker set was used as illustrated left

6. Methods • The different kicking styles were analyzed for moment forces and power. • The first style looked at was the straight kick- where the athlete approaches the ball straight on. • The next style was the sweep kick- where the athlete approaches the ball from the side. • Subject was a male 22 year old experienced soccer player • Performed 4 trials of each kick, and we attempted to analyze the best trials

7. Straight Kick • Approaching the ball straight on • Mostly a flexion/extension action • Minimal abduction/adduction

8. Sweep Kick • Approaching the ball at an angle • Substantial abduction/adduction components

9. Joint Power Analysis (Flexion/ Extension) Straight Kick • Hip: Extension is negative Flexion is positive • Knee: Extension is positive Flexion is negative • Moment power(W) Positive = concentric Negative = eccentric

10. Hip: Extension is negative Flexion is positive Knee: Extension is positive Flexion is negative Moment power(W) Positive = concentric Negative = eccentric Joint Power Analysis (Flexion/ Extension) Sweep Kick

11. Hip: Extension is negative Flexion is positive Knee: Extension is positive Flexion is negative Moment power(W) Positive = concentric Negative = eccentric Joint Power Analysis (Abduction/ Adduction) Sweep Kick

12. Analysis Summary • The hip flexors and extensors are responsible for producing the majority of the kicking force • During knee extension, the flexors are active just before strike preventing hyperextension • Hip extensor action just prior to contact is what initiates knee extension

13. Analysis Summary • The abduction/ adduction curves follow a similar path to the flexion/ extension graphs. • The magnitudes of the abduction/ adduction are substantial for the velocities and moments, but much smaller for the powers. • Anatomical structures resist moments thus reducing powers

14. Conclusions and Recommendations • Our results supported the previous studies concerning the powers and forces for flexion/ extension • Our abduction/ adduction results were what we expected based on anatomical predicions • Some studies have shown that the sweep kick produces higher ball velocities, possibly due to the added abduction/ adduction forces of the limb. • Now that more 3D capture technology is available more kinetic studies should be done.