Table 2
Approximate contributions to impact racquet velocity (%)
Power serve
Topspin forehand (forward direction)
Shoulder
10
15
Upper arm
Horizontal flexion
15
25
Internal rotation
40
40
Forearm
Extension
Negligible
Negligible
Pronation
5
Negligible
Hand
Flexion (palm/ulnar)
30
–
Flexion (palmar/radial)
–
20