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.