ITF Coaches Education Programme Biomechanics of the return of serve

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Christina Baker
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1 ITF Coaches Education Programme Biomechanics of the return of serve Original article: Kleinoder, H. (2001). ITF CSSR, 24, 5-6

2 Introduction Kinematic analysis Feature of biomechanics Uses high-speed cameras operating at 200 to 400 frames per second Delivers information about invisible aspects of human movement co-ordination: The total time budget of the return The quality of the impact on the racket Supports the coach s eye with precise information for: Identifying mistakes Finding out appropriate solutions

3 Considerations to study Most important considerations for coordinating returns on the 1 st and 2 nd serves: The available time budget The time management of the players

4 Racket velocity & segment interaction Mean initial velocity: 1 st serve: 160±15 km/h 2 nd serve: 117±10 km/h Mean time budget for the return on clay: 1 st serve: 900 ms 2 nd serve: 1200 ms

5 Racket velocity & segment interaction Fast courts: time budget decreases by approximately 200 ms. Other aspects that explain the differences: Conditions of ball flight Player strategies (e.g. the position of the receiver)

6 Regulation of movement Players adapt their racket movement to the demands of the approaching ball Shortly before the point of impact the synchronization (sequencing) of maximum segment velocities (i.e. first shoulder, then elbow, wrist and racket) cannot be clearly seen during the return This is in clear contrast to velocity generation on the other strokes (groundstrokes & serve)

7 Absence of maximum segment velocities Unpredictable nature of the return High time pressure under which players are placed (especially during the 1 st serve) Very high demand of precision on the return: 1 st serve return: precision-orientation 2 nd serve return: velocity generation

8 Racket velocity At impact is much lower during 1 st serve returns This is also true for the segment velocities of the arm (shoulder, elbow and wrist). Pro players do not reach maximum racket velocity at impact during service returns

9 Racket velocity Racket velocity decreases during the 1 st serve return and, significantly less, during the 2 nd serve return This variation can be attributed to the variable conditions encountered during competition

10 Reprogramming Very important factor on the return Effective receivers have the ability to reprogram an incorrect decision within a very short time interval I.e: Initially anticipating incorrectly a forehand return but quickly adjust and play a backhand return for a winner (e.g. Sampras)

11 Impact Precision of the return can be measured by the number of off-centre impacts In pro tennis, this number is typically very low

12 Impact Players of lesser standards: Have widespread points of impact, This may contribute to injuries (i.e. tennis elbow). Effects of an off-centre impact: Rapid rotation of the racket (in 35 ms, not even visible to the human eye) Can stress the muscles of the arm.

13 Summary On the basis of these recent research it is highly recommended to: Train anticipatory abilities; Train returns by varying the time pressure imposed on the players in order to improve their time management; Offer tasks for reprogramming (e.g. backhand to forehand return) and; Work to control impact location on the racket

ITF Coaches Education Programme Biomechanics of the forehand stroke

ITF Coaches Education Programme Biomechanics of the forehand stroke Original article: Bahamonde, R. (2001). ITF CSSR, 24, 6-8 Introduction The tennis forehand stroke has changed drastically over the last