Table 2. Means (standard deviations) for the two grips for forehand topspin and backspin strokes.
Variables Forehand Topspin Forehand Backspin
Shakehand (n=18) Penhold (n=9) Shakehand (n=18) Penhold (n=9)
Ball forward (+) velocity (m/s) 16.10 (1.13) 15.89 (1.45) 14.52 (1.10) 14.37 (0.78)
Ball downward velocity (-) (m/s) -1.80 (-0.26) -1.72 (-0.16) -1.41 (-0.27) -1.40 (-0.27)
Peak racket resultant velocity (m/s) 18.62 (1.51) 18.15 (1.33) 18.76 (1.52) 18.37 (1.89)
Timing of peak racket resultant velocity (s) 0.11 (0.01) 0.14 (0.04) * 0.11 (0.02) 0.12 (0.04)
Initial trunk right rotation (-) angle (°) -19.86 (11.76) -11.34 (12.01) -16.35 (12.41) -8.37 (11.94)
Final trunk right rotation (-) angle (°) -5.99 (7.15) -2.33 (7.29) -6.08 (8.13) -2.77 (7.47)
Trunk left (+) rotation angular velocity (°/s) 154.2 (169.0) 145.0 (67.7) 97.1 (193.5) 74.1 (83.5)
Initial shoulder abduction (-) angle (°) -22.51 (8.62) -28.00 (6.88) -21.85 (7.90) -27.25 (8.66)
Final shoulder abduction (-) angle (°) -43.72 (7.64) -48.35 (8.36) -41.16 (6.21) -45.20 (9.05)
Shoulder adduction (+) / abduction (-) angular velocity (°/s) -34.53 (161.52) 42.77 (220.86) -3.78 (166.88) 13.63 (194.06)
Initial shoulder flexion (-) angle (°) -15.40 (19.33) -16.35 (18.39) -14.44 (18.66) -12.73 (20.52)
Final shoulder flexion (-) angle (°) -57.07 (16.81) -60.66 (17.72) -60.61 (17.90) -59.57 (19.60)
Shoulder flexion (-) angular velocity (°/s) -802.5 (268.8) -953.6 (281.8) -775.4 (248.7) -998.6 (332.0)
Initial shoulder external rotation (-) angle (°) -42.62 (10.72) -27.88 (19.81) * -43.50 (10.41) -33.80 (16.52)
Final shoulder internal (+) / external (-) rotation angle (°) -9.88 (14.78) 6.94 (18.63) * -6.84 (13.43) 5.49 (19.35)
Shoulder internal (+) rotation angular velocity (°/s) 1096.6 (237.8) 1082.1 (340.8) 1099.0 (236.3) 1077.1 (336.8)
Initial elbow flexion (-) angle (°) -55.73 (15.11) -56.11 (15.91) -56.54 (16.60) -55.67 (19.46)
Final elbow flexion (-) angle (°) -59.09 (14.74) -53.33 (15.09) -59.89 (14.97) -56.22 (18.18)
Elbow flexion (-) angular velocity (°/s) -72.15 (172.66) -176.18 (149.32) -78.80 (204.59) -191.12 (191.99)
Initial forearm pronation (+) angle (°) 129.6 (18.0) 137.0 (16.2) 130.3 (20.1) 133.0 (17.7)
Final forearm pronation (+) angle (°) 132.4 (14.2) 136.7 (16.7) 133.1 (14.6) 137.6 (16.6)
Forearm pronation (+) angular velocity (°/s) 98.5 (180.7) 213.6 (111.1) 102.1 (210.3) 207.3 (116.8)
Initial racket adduction (+) angle (°) 6.59 (13.96) 44.98 (11.13) # 8.13 (14.38) 45.66 (11.38) #
Final racket adduction (+) / abduction (-) angle (°) 2.66 (12.73) 34.70 (9.28) # 2.35 (13.14) 32.98 (10.20) #
Racket adduction (+) / abduction (-) angular velocity (°/s) -175.6 (75.3) -212.7 (121.5) -191.7 (94.1) -194.9 (108.6)
Initial racket extension (+) / flexion (-) angle (°) 1.99 (19.38) -48.28 (23.87) # 2.35 (21.16) -45.97 (25.84) #
Final racket extension (+) / flexion (-) angle (°) 0.38 (14.17) -33.28 (17.52) # 0.02 (14.20) -33.19 (15.43) #
Racket extension (+) / flexion (-) angular velocity (°/s) -47.8 (102.1) 196.1(99.6) # -26.9 (121.1) 189.1 (116.7) #
Initial racket external rotation (-) angle (°) -28.65 (18.63) -79.10 (15.14) # -28.33 (19.76) -79.17 (17.29) #
Final racket external rotation (-) angle (°) -31.32 (16.16) -72.13 (12.43) # -31.25 (16.79) -70.14 (12.62) #
Racket internal (+) rotation angular velocity (°/s) 13.23 (87.14) 106.88 (78.35) * 16.49 (101.37) 88.21 (90.30)
Initial joint angles were extracted at the initiation of the forward stroke. Final joint angles and angular velocities were extracted at the time of the peak racket resultant velocity.
* p < 0.05,
# p < 0.001.