Table 3. Means (standard deviations) for the two grips for backhand topspin and backspin strokes.
Variables Backhand Topspin Backhand Backspin
Shakehand (n=18) Penhold (n=9) Shakehand (n=18) Penhold (n=9)
Ball forward (+) velocity (m/s) 16.13 (0.95) 15.11 (0.78) * 14.63 (1.15) 13.71 (0.92) *
Ball downward velocity (-) (m/s) -2.04 (-0.22) -1.93 (-0.25) -1.61 (-0.18) -1.35 (-0.21)
Peak racket resultant velocity (m/s) 17.04 (1.37) 14.55 (1.18) # 17.86 (1.36) 15.36 (1.09) #
Timing of peak racket resultant velocity (s) 0.13 (0.02) 0.15 (0.02) 0.13 (0.03) 0.16 (0.03) *
Initial trunk left rotation (+) angle (°) 17.83 (6.55) 21.74 (5.34) 16.73 (4.66) 19.36 (5.26)
Final trunk left rotation (+) angle (°) 7.31 (7.35) 17.47 (4.98) # 4.15 (6.45) 14.20 (6.58) #
Trunk left (+) / right (-) rotation angular velocity (°/s) -101.6 (98.04) 2.48 (88.50) * -128.2 (99.14) -15.87 (80.20)
Initial shoulder abduction (-) angle (°) -38.44 (6.75) -34.67 (6.58) -40.28 (6.81) -36.80 (7.33)
Final shoulder abduction (-) angle (°) -30.91 (9.48) -40.91 (8.93) * -27.36 (9.85) -34.84 (8.36)
Shoulder adduction (+) angular velocity (°/s) 112.25 (119.43) 20.15 (100.92) 159.55 (95.72) 76.46 (130.78)
Initial shoulder flexion (-) angle (°) -47.83 (13.01) -45.38 (10.68) -44.08 (14.09) -42.62 (8.78)
Final shoulder flexion (-) angle (°) -84.50 (10.76) -78.58 (13.75) -83.05 (12.19) -79.95 (15.83)
Shoulder flexion (-) angular velocity (°/s) -229.53 (133.71) -315.27 (188.66) -210.28 (122.03) -269.36 (181.77)
Initial shoulder internal rotation (+) angle (°) 66.12 (16.40) 59.82 (14.72) 64.59 (16.95) 55.80 (13.92)
Final shoulder internal (+) rotation angle (°) 55.63 (11.62) 46.92 (14.90) 57.22 (12.09) 45.23 (9.36) *
Shoulder external (-) rotation angular velocity (°/s) -726.02 (202.98) -498.06 (394.52) -829.12 (227.21) -766.64 (332.10)
Initial elbow flexion (-) angle (°) -83.23 (5.73) -84.79 (11.98) -77.10 (8.18) -78.76 (12.77)
Final elbow flexion (-) angle (°) -55.43 (9.39) -62.52 (10.15) -55.52 (9.80) -58.45 (9.78)
Elbow extension (+) angular velocity (°/s) 558.64 (140.19) 619.45 (167.95) 419.42 (176.97) 451.41 (170.42)
Initial forearm pronation (+) angle (°) 87.52 (17.39) 79.95 (13.98) 88.08 (21.00) 85.71 (14.77)
Final forearm pronation (+) angle (°) 74.08 (17.65) 71.33 (13.76) 73.46 (18.76) 72.54 (12.51)
Forearm supination (-) angular velocity (°/s) -422.60 (335.01) -41.91 (309.07) -610.53 (402.54) -319.97 (296.21)
Initial racket adduction (+) / abduction (-) angle (°) -27.72 (16.73) 23.45 (15.63) # -28.86 (17.21) 20.36 (13.85) #
Final racket adduction (+) / abduction (-) angle (°) -21.15 (10.07) 11.17 (10.81) # -20.74 (10.32) 9.38 (9.38) #
Racket adduction (+) / abduction (-) angular velocity (°/s) 328.61 (350.26) -97.80 (146.89) 244.62 (320.05) -82.96 (147.04)
Initial racket flexion (-) angle (°) -47.48 (16.88) -96.10 (21.35) # -47.00 (15.67) -88.87 (27.77) #
Final racket flexion (-) angle (°) -9.93 (12.55) -52.58 (15.11) # -7.03 (12.06) -44.24 (14.01) #
Racket extension (+) angular velocity (°/s) 1252.6 (380.1) 1042.7 (358.2) 1347.1 (447.5) 828.5 (314.4)
Initial racket external rotation (-) angle (°) -66.36 (9.15) -62.41 (9.14) -66.97 (9.27) -58.57 (12.64)
Final racket external rotation (-) angle (°) -70.13 (13.27) -59.96 (9.08) -69.50 (13.58) -61.03 (9.00)
Racket external (-) rotation angular velocity (°/s) -135.58 (203.01) -107.55 (149.48) -201.20 (197.74) -200.29 (111.89)
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 < 0.01,
# p < 0.001.