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Table 2 Mean and standard deviation values for peak lower limb and ball toss kinematics

From: Effects of Lumbar Spine Abnormality and Serve Types on Lumbar Kinematics in Elite Adolescent Tennis Players

  Pars No pars
  Flat Kick Flat Kick
  Female Male Female Male Female Male Female Male
Front knee angle (°) 77.3 ± 8.2 68.2 ± 5.7 78.9 ± 9.5 67.7 ± 5.7 66.6 ± 9.6 67.9 ± 8.0 65.9 ± 8.9 69.2 ± 8.8
Back knee angle (°) 73.0 ± 9.6 79.9 ± 10.2 76.2 ± 11.8 79.3 ± 10.8 77.8 ± 8.5 73.1 ± 11.7 75.4 ± 11.2 73.6 ± 14.3
Front hip extension angular velocity (°/s)* − 186 ± 12.7 − 193.9 ± 76.1 − 198.9 ± 19.4 − 199.2 ± 69.6 − 255.2 ± 54.6 − 214.1 ± 72.3 − 236.3 ± 53.8 − 203.7 ± 66.4
Front knee extension angular velocity (°/s)* − 452.5 ± 28.8 − 462.4 ± 161.3 − 505.8 ± 37.3 − 507.2 ± 158.2 − 581.9 ± 129.1 − 478.7 ± 98 − 633.5 ± 147.4 − 520.7 ± 121.7
Back hip extension angular velocity (°/s)* − 175 ± 34.5 − 230.2 ± 84.8 − 173.5 ± 8.9 − 236.3 ± 90.1 − 291.3 ± 68.6 − 240.1 ± 87.9 − 262.7 ± 86 − 231.6 ± 85
Back knee extension angular velocity (°/s) − 510.1 ± 41.1 − 599.6 ± 149.7 − 510.8 ± 32.8 − 596.8 ± 123.9 − 615.7 ± 107.4 − 557.4 ± 90.4 − 634.1 ± 136 − 568.2 ± 94.9
LHJCL velocity (m/s)* 1.4 ± 0.1 1.4 ± 0.4 1.4 ± 0.1 1.5 ± 0.4 1.6 ± 0.2 1.4 ± 0.2 1.6 ± 0.3 1.5 ± 0.3
RHJCL velocity (m/s) 1.6 ± 0.1 2 ± 0.4 1.8 ± 0.1 2.2 ± 0.4 2 ± 0.2 2 ± 0.2 2.1 ± 0.4 2.2 ± 0.3
Racquet velocity X (m/s)* 32.1 ± 2 37.3 ± 5.3 30.4 ± 1.2 32.8 ± 4.2 34.7 ± 3.2 37.2 ± 5.9 30.3 ± 3.5 31.5 ± 4.9
Racquet velocity Y (m/s) 6.5 ± 1.5 8.3 ± 1.8 8.8 ± 2.1 8.4 ± 2.5 5.6 ± 2.3 6.9 ± 1.9 5.9 ± 2.3 7.7 ± 2
Racquet velocity Z (m/s)* 23.3 ± 1.6 24.7 ± 2.1 22.8 ± 0.9 24.2 ± 2.9 24 ± 3.1 24.3 ± 3.8 22.8 ± 3.3 23 ± 3.7
Toss height (cm) 319 ± 16.0 317.1 ± 33.5 319.1 ± 8.0 315.9 ± 23.0 331.6 ± 20.7 306.5 ± 26.1 332.8 ± 25.2 305.1 ± 25.2
Relative toss height (ratio)^ 0.51 ± 0.01 0.55 ± 0.06 0.51 ± 0.01 0.55 ± 0.05 0.48 ± 0.04 0.54 ± 0.06 0.48 ± 0.05 0.55 ± 0.06
Lateral impact position (cm)* − 24.3 ± 6.0 − 31.1 ± 18.8 − 38.8 ± 11.2 − 44.5 ± 24.1 − 4.5 ± 25.5 − 19.8 ± 21.1 − 25.1 ± 22.0 − 43.0 ± 24.1
Relative lateral impact position (ratio)* − 0.15 ± 0.04 − 0.18 ± 0.1 − 0.24 ± 0.08 − 0.25 ± 0.13 − 0.03 ± 0.16 − 0.12 ± 0.12 − 0.16 ± 0.13 − 0.26 ± 0.14
Forward impact position (cm)*^ − 38.0 ± 13.6 − 53.2 ± 31.8 − 31.1 ± 11.1 − 42.4 ± 12.2 − 42.8 ± 10.8 − 61.6 ± 11.9 − 23.9 ± 13.7 − 38.1 ± 16.1
Relative forward impact position (ratio)*^ − 0.24 ± 0.09 − 0.3 ± 0.18 − 0.2 ± 0.08 − 0.24 ± 0.06 − 0.27 ± 0.07 − 0.37 ± 0.08 − 0.15 ± 0.09 − 0.23 ± 0.09
Impact height (cm) 243.8 ± 5.8 257.7 ± 18.2 242.0 ± 8.0 257.0 ± 19.5 246.0 ± 11.2 250.9 ± 15.8 246.9 ± 12.5 249.1 ± 16.2
Relative impact height (ratio) 0.66 ± 0.02 0.69 ± 0.06 0.67 ± 0.01 0.68 ± 0.02 0.65 ± 0.02 0.66 ± 0.02 0.65 ± 0.02 0.67 ± 0.03
Drop distance (cm)^ 75.2 ± 10.9 59.4 ± 36.4 77.1 ± 3.7 58.9 ± 26.7 85.6 ± 20.8 55.6 ± 24.8 85.9 ± 26.3 56.0 ± 22.0
  1. LHJCL left hip joint center linear, RHJCL right hip joint center linear
  2. *Significant main effect for serve (p< 0.01)
  3. ^Significant main effect for sex (p< 0.01)
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