> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uplift.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Tennis Overhand Serve: Normative Ranges

> Full percentile reference tables (5th–95th) for tennis overhand serve metrics, broken out by competition level.

This page collects the complete normative reference tables for the tennis overhand serve — the full 5th–95th percentile range for each competition level, drawn from the same normative dataset that backs the [Normative Ranges](https://docs.uplift.ai/biomechanics/normative-ranges.md) guide. See that page for how to interpret these tables.

Each competition-level dataset was built by pooling all valid serve sessions per athlete, selecting the single session closest to that athlete's overall average across all metrics, then re-analyzing with the latest biomechanical analysis software and removing sessions that failed Uplift's quality assurance tests. Unlike baseball, the tennis dataset currently only supports **Youth**, **Professional**, and **Broad (All Levels)** populations — College and High School brackets are not yet available.

## Youth Sample

Reference dataset built from 50 unique youth athletes (227 valid serve sessions before selecting one representative session per athlete) performing a serve in 2025.

### Kinematic Sequence – Forward (Serve Direction) Angular Velocities & Speedups

Prefer higher velocities and speedup factors for better performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Peak Torso Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-torso-forward-angular-velocity) | 147 | 160 | 184 | 206 | 234 | 256 | 264 | deg/s |
| [Peak Upper Arm Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-upper-arm-forward-angular-velocity) | 653 | 680 | 805 | 887 | 997 | 1073 | 1120 | deg/s |
| [Peak Forearm Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-forearm-forward-angular-velocity) | 746 | 776 | 858 | 976 | 1101 | 1212 | 1256 | deg/s |
| [Forward Trunk Arm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/forward-trunk-arm-speedup) | 3.22 | 3.38 | 3.80 | 4.32 | 4.91 | 5.45 | 5.88 | ratio |
| [Forward Upper Arm Forearm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/forward-upper-arm-forearm-speedup) | 0.80 | 0.85 | 0.97 | 1.09 | 1.25 | 1.41 | 1.54 | ratio |

### Kinematic Sequence – Twist Angular Velocities & Speedups

Prefer higher velocities and speedup factors for better performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Peak Pelvis Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-pelvis-twist-angular-velocity) | 190 | 215 | 284 | 366 | 446 | 495 | 512 | deg/s |
| [Peak Torso Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-torso-twist-angular-velocity) | 253 | 282 | 335 | 379 | 417 | 450 | 473 | deg/s |
| [Peak Upper Arm Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-upper-arm-twist-angular-velocity) | 214 | 270 | 333 | 411 | 495 | 566 | 628 | deg/s |
| [Twist Trunk Arm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/twist-trunk-arm-speedup) | 0.60 | 0.71 | 0.89 | 1.10 | 1.35 | 1.60 | 1.75 | ratio |
| [Twist Pelvis Torso Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/twist-pelvis-torso-speedup) | 0.70 | 0.78 | 0.87 | 1.05 | 1.26 | 1.58 | 1.71 | ratio |

### Loading Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Loading Phase Max Knee Flexion Front Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-knee-flexion) | 50 | 53 | 59 | 68 | 78 | 85 | 89 | deg |
| [Loading Phase Max Knee Flexion Back Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-knee-flexion) | 42 | 53 | 65 | 70 | 81 | 87 | 93 | deg |
| [Loading Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-trunk-tilt) | -29 | -25 | -21 | -15 | -11 | -6 | -1 | deg |
| [Loading Phase Pelvis Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-pelvis-tilt) | -9 | -8 | -6 | -3 | 0 | 1 | 2 | deg |
| [Loading Phase Shoulder Hip Separation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-shoulder-hip-separation) | 0 | 3 | 11 | 19 | 29 | 35 | 40 | deg |
| [Loading Phase Ball Release Angle](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-ball-release-angle) | 76 | 95 | 105 | 122 | 137 | 152 | 156 | deg |
| [Trunk Coil](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/trunk-coil) | -142 | -138 | -130 | -119 | -111 | -104 | -99 | deg |
| [Pelvis Coil](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/pelvis-coil) | -132 | -129 | -122 | -113 | -108 | -99 | -87 | deg |
| [Trunk Stretch](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/trunk-stretch) | 124 | 137 | 151 | 160 | 171 | 181 | 186 | deg |
| [Pelvis Stretch](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/pelvis-stretch) | 86 | 102 | 118 | 130 | 144 | 158 | 164 | deg |
| [Release Phase Elbow Angle](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/release-phase-elbow-angle) | 1 | 2 | 7 | 19 | 27 | 40 | 44 | deg |
| [Max Front Knee Valgus (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/max-front-knee-valgus) | -0.041 | -0.036 | -0.029 | -0.021 | -0.016 | -0.009 | -0.006 | × height |
| [Max Back Knee Valgus (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/max-back-knee-valgus) | -0.023 | -0.021 | -0.017 | -0.011 | -0.006 | -0.004 | -0.003 | × height |

### Cocking and Acceleration Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Cocking Phase Max Shoulder External Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-external-rotation) | 154 | 163 | 170 | 179 | 188 | 194 | 199 | deg |
| [Cocking Phase Shoulder Hyperangulation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-hyperangulation) | 136 | 141 | 146 | 155 | 163 | 172 | 178 | deg |
| [Cocking Phase Max X Factor](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-max-x-factor) | -6 | 0 | 9 | 17 | 26 | 35 | 38 | deg |
| [Cocking Phase Shoulder Horizontal Abduction](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-horizontal-abduction) | 61 | 68 | 75 | 87 | 98 | 102 | 104 | deg |
| [Acceleration Phase Max Knee Extension Velocity Front Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-knee-extension-velocity) | 238 | 269 | 298 | 345 | 381 | 414 | 431 | deg/s |
| [Acceleration Phase Max Knee Extension Velocity Back Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-knee-extension-velocity) | 182 | 223 | 304 | 351 | 394 | 420 | 433 | deg/s |
| [Acceleration Phase Max Elbow Extension Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-elbow-extension-velocity) | 852 | 920 | 1037 | 1155 | 1251 | 1329 | 1422 | deg/s |

### Contact Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Contact Phase Elbow Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-elbow-flexion) | 29 | 31 | 39 | 46 | 53 | 60 | 63 | deg |
| [Contact Phase Shoulder Abduction](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-shoulder-abduction) | 103 | 106 | 113 | 123 | 129 | 135 | 139 | deg |
| [Contact Phase X Factor](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-x-factor) | -8 | -5 | -1 | 3 | 8 | 14 | 16 | deg |
| [Contact Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-tilt) | 29 | 31 | 34 | 38 | 42 | 46 | 47 | deg |
| [Time to Contact](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/time-to-contact) | 0.60 | 0.72 | 0.80 | 0.91 | 1.00 | 1.11 | 1.17 | s |
| [Contact Phase Trunk Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-flexion) | 1 | 4 | 10 | 14 | 20 | 30 | 32 | deg |
| [Contact Phase Trunk Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-rotation) | -40 | -38 | -33 | -24 | -12 | -5 | -2 | deg |
| [Contact Phase Pelvis Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-pelvis-rotation) | -43 | -42 | -38 | -33 | -25 | -19 | -14 | deg |
| [Contact Phase Wrist Height (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-wrist-height-normalized) | 1.14 | 1.16 | 1.19 | 1.22 | 1.24 | 1.27 | 1.28 | × height |
| [Contact Phase Wrist Velocity (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-wrist-velocity-normalized) | 761 | 800 | 829 | 858 | 889 | 921 | 932 | unconfirmed |

### Landing Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Finish Phase Trunk Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/finish-phase-trunk-flexion) | 35 | 40 | 45 | 50 | 55 | 63 | 67 | deg |
| [Finish Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/finish-phase-trunk-tilt) | -15 | -12 | -7 | -1 | 4 | 8 | 13 | deg |
| [Forward Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-forward) | 0.072 | 0.151 | 0.270 | 0.361 | 0.440 | 0.509 | 0.538 | × height |
| [Open-Side Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-open-side) | -0.033 | 0.000 | 0.089 | 0.176 | 0.263 | 0.346 | 0.384 | × height |
| [Vertical Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-vertical) | 0.095 | 0.112 | 0.129 | 0.148 | 0.168 | 0.192 | 0.202 | × height |

## Professional Sample

Reference dataset built from 32 unique professional athletes (300 valid serve sessions before selecting one representative session per athlete) performing a serve in 2025.

### Kinematic Sequence – Forward (Serve Direction) Angular Velocities & Speedups

Prefer higher velocities and speedup factors for better performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Peak Torso Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-torso-forward-angular-velocity) | 168 | 180 | 198 | 216 | 237 | 263 | 277 | deg/s |
| [Peak Upper Arm Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-upper-arm-forward-angular-velocity) | 696 | 764 | 837 | 924 | 1031 | 1088 | 1116 | deg/s |
| [Peak Forearm Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-forearm-forward-angular-velocity) | 637 | 772 | 921 | 1041 | 1142 | 1281 | 1325 | deg/s |
| [Forward Trunk Arm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/forward-trunk-arm-speedup) | 3.29 | 3.38 | 3.74 | 4.22 | 4.81 | 5.27 | 5.42 | ratio |
| [Forward Upper Arm Forearm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/forward-upper-arm-forearm-speedup) | 0.57 | 0.76 | 0.98 | 1.16 | 1.31 | 1.45 | 1.54 | ratio |

### Kinematic Sequence – Twist Angular Velocities & Speedups

Prefer higher velocities and speedup factors for better performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Peak Pelvis Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-pelvis-twist-angular-velocity) | 190 | 253 | 334 | 382 | 414 | 446 | 461 | deg/s |
| [Peak Torso Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-torso-twist-angular-velocity) | 259 | 275 | 316 | 353 | 391 | 425 | 441 | deg/s |
| [Peak Upper Arm Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-upper-arm-twist-angular-velocity) | 182 | 225 | 304 | 381 | 462 | 572 | 620 | deg/s |
| [Twist Trunk Arm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/twist-trunk-arm-speedup) | 0.56 | 0.69 | 0.90 | 1.07 | 1.28 | 1.55 | 1.77 | ratio |
| [Twist Pelvis Torso Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/twist-pelvis-torso-speedup) | 0.70 | 0.74 | 0.84 | 0.94 | 1.07 | 1.48 | 1.75 | ratio |

### Loading Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Loading Phase Max Knee Flexion Front Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-knee-flexion) | 53 | 56 | 61 | 67 | 77 | 86 | 88 | deg |
| [Loading Phase Max Knee Flexion Back Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-knee-flexion) | 56 | 62 | 71 | 78 | 85 | 89 | 93 | deg |
| [Loading Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-trunk-tilt) | -30 | -28 | -26 | -23 | -19 | -14 | -12 | deg |
| [Loading Phase Pelvis Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-pelvis-tilt) | -11 | -9 | -7 | -5 | -4 | -1 | 1 | deg |
| [Loading Phase Shoulder Hip Separation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-shoulder-hip-separation) | 5 | 7 | 10 | 16 | 23 | 31 | 34 | deg |
| [Loading Phase Ball Release Angle](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-ball-release-angle) | 71 | 89 | 100 | 116 | 132 | 144 | 157 | deg |
| [Trunk Coil](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/trunk-coil) | -139 | -136 | -129 | -122 | -116 | -109 | -104 | deg |
| [Pelvis Coil](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/pelvis-coil) | -130 | -129 | -125 | -117 | -111 | -101 | -88 | deg |
| [Trunk Stretch](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/trunk-stretch) | 128 | 135 | 146 | 155 | 162 | 170 | 173 | deg |
| [Pelvis Stretch](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/pelvis-stretch) | 94 | 103 | 113 | 125 | 135 | 142 | 146 | deg |
| [Release Phase Elbow Angle](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/release-phase-elbow-angle) | 2 | 5 | 14 | 27 | 36 | 41 | 45 | deg |
| [Max Front Knee Valgus (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/max-front-knee-valgus) | -0.039 | -0.035 | -0.028 | -0.022 | -0.014 | -0.008 | -0.006 | × height |
| [Max Back Knee Valgus (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/max-back-knee-valgus) | -0.021 | -0.019 | -0.015 | -0.011 | -0.007 | -0.005 | -0.004 | × height |

### Cocking and Acceleration Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Cocking Phase Max Shoulder External Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-external-rotation) | 169 | 172 | 180 | 187 | 192 | 196 | 199 | deg |
| [Cocking Phase Shoulder Hyperangulation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-hyperangulation) | 138 | 145 | 154 | 160 | 168 | 176 | 184 | deg |
| [Cocking Phase Max X Factor](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-max-x-factor) | 4 | 6 | 9 | 16 | 23 | 31 | 33 | deg |
| [Cocking Phase Shoulder Horizontal Abduction](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-horizontal-abduction) | 84 | 88 | 93 | 98 | 104 | 109 | 111 | deg |
| [Acceleration Phase Max Knee Extension Velocity Front Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-knee-extension-velocity) | 265 | 281 | 314 | 343 | 393 | 435 | 444 | deg/s |
| [Acceleration Phase Max Knee Extension Velocity Back Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-knee-extension-velocity) | 238 | 262 | 326 | 367 | 404 | 439 | 465 | deg/s |
| [Acceleration Phase Max Elbow Extension Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-elbow-extension-velocity) | 787 | 913 | 1058 | 1126 | 1192 | 1283 | 1338 | deg/s |

### Contact Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Contact Phase Elbow Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-elbow-flexion) | 24 | 27 | 31 | 37 | 44 | 49 | 54 | deg |
| [Contact Phase Shoulder Abduction](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-shoulder-abduction) | 118 | 123 | 128 | 135 | 142 | 146 | 148 | deg |
| [Contact Phase X Factor](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-x-factor) | -4 | -2 | 2 | 5 | 10 | 15 | 19 | deg |
| [Contact Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-tilt) | 24 | 26 | 30 | 33 | 36 | 40 | 42 | deg |
| [Time to Contact](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/time-to-contact) | 0.30 | 0.65 | 0.86 | 0.97 | 1.04 | 1.10 | 1.15 | s |
| [Contact Phase Trunk Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-flexion) | -2 | -1 | 4 | 9 | 12 | 16 | 19 | deg |
| [Contact Phase Trunk Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-rotation) | -55 | -51 | -39 | -32 | -25 | -20 | -12 | deg |
| [Contact Phase Pelvis Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-pelvis-rotation) | -71 | -59 | -45 | -40 | -35 | -30 | -25 | deg |
| [Contact Phase Wrist Height (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-wrist-height-normalized) | 1.19 | 1.21 | 1.23 | 1.25 | 1.27 | 1.29 | 1.30 | × height |
| [Contact Phase Wrist Velocity (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-wrist-velocity-normalized) | 718 | 744 | 807 | 835 | 860 | 877 | 890 | unconfirmed |

### Landing Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Finish Phase Trunk Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/finish-phase-trunk-flexion) | 27 | 32 | 39 | 46 | 52 | 58 | 61 | deg |
| [Finish Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/finish-phase-trunk-tilt) | -15 | -12 | -7 | -1 | 6 | 11 | 15 | deg |
| [Forward Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-forward) | 0.163 | 0.205 | 0.269 | 0.370 | 0.455 | 0.531 | 0.616 | × height |
| [Open-Side Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-open-side) | -0.032 | 0.001 | 0.060 | 0.167 | 0.291 | 0.371 | 0.433 | × height |
| [Vertical Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-vertical) | 0.114 | 0.118 | 0.130 | 0.158 | 0.180 | 0.203 | 0.255 | × height |

## Broad Sample (All Levels)

Reference dataset built from 82 unique athletes (527 valid serve sessions before selecting one representative session per athlete) performing a serve in 2025, pooled across all competition levels.

### Kinematic Sequence – Forward (Serve Direction) Angular Velocities & Speedups

Prefer higher velocities and speedup factors for better performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Peak Torso Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-torso-forward-angular-velocity) | 147 | 165 | 190 | 211 | 235 | 259 | 270 | deg/s |
| [Peak Upper Arm Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-upper-arm-forward-angular-velocity) | 651 | 723 | 825 | 905 | 1018 | 1085 | 1117 | deg/s |
| [Peak Forearm Forward Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-forearm-forward-angular-velocity) | 676 | 764 | 875 | 1013 | 1130 | 1251 | 1307 | deg/s |
| [Forward Trunk Arm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/forward-trunk-arm-speedup) | 3.27 | 3.38 | 3.76 | 4.29 | 4.89 | 5.42 | 5.84 | ratio |
| [Forward Upper Arm Forearm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/forward-upper-arm-forearm-speedup) | 0.71 | 0.80 | 0.97 | 1.13 | 1.30 | 1.45 | 1.55 | ratio |

### Kinematic Sequence – Twist Angular Velocities & Speedups

Prefer higher velocities and speedup factors for better performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Peak Pelvis Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-pelvis-twist-angular-velocity) | 190 | 224 | 305 | 376 | 422 | 462 | 494 | deg/s |
| [Peak Torso Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-torso-twist-angular-velocity) | 256 | 279 | 324 | 364 | 401 | 435 | 461 | deg/s |
| [Peak Upper Arm Twist Angular Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/peak-upper-arm-twist-angular-velocity) | 191 | 238 | 320 | 397 | 492 | 594 | 660 | deg/s |
| [Twist Trunk Arm Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/twist-trunk-arm-speedup) | 0.59 | 0.70 | 0.90 | 1.09 | 1.32 | 1.66 | 1.92 | ratio |
| [Twist Pelvis Torso Speedup](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/twist-pelvis-torso-speedup) | 0.70 | 0.76 | 0.85 | 0.98 | 1.18 | 1.56 | 1.73 | ratio |

### Loading Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Loading Phase Max Knee Flexion Front Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-knee-flexion) | 51 | 54 | 60 | 68 | 78 | 85 | 89 | deg |
| [Loading Phase Max Knee Flexion Back Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-knee-flexion) | 52 | 56 | 67 | 75 | 84 | 89 | 93 | deg |
| [Loading Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-trunk-tilt) | -29 | -28 | -25 | -20 | -14 | -9 | -5 | deg |
| [Loading Phase Pelvis Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-pelvis-tilt) | -11 | -9 | -7 | -5 | -2 | 0 | 2 | deg |
| [Loading Phase Shoulder Hip Separation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-shoulder-hip-separation) | 2 | 5 | 10 | 17 | 25 | 34 | 37 | deg |
| [Loading Phase Ball Release Angle](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/loading-phase-ball-release-angle) | 71 | 91 | 104 | 118 | 135 | 149 | 157 | deg |
| [Trunk Coil](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/trunk-coil) | -141 | -138 | -129 | -122 | -113 | -106 | -100 | deg |
| [Pelvis Coil](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/pelvis-coil) | -132 | -129 | -124 | -116 | -109 | -99 | -86 | deg |
| [Trunk Stretch](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/trunk-stretch) | 127 | 136 | 147 | 156 | 166 | 174 | 180 | deg |
| [Pelvis Stretch](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/pelvis-stretch) | 86 | 102 | 115 | 127 | 138 | 148 | 155 | deg |
| [Release Phase Elbow Angle](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/release-phase-elbow-angle) | 1 | 3 | 11 | 22 | 34 | 41 | 47 | deg |
| [Max Front Knee Valgus (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/max-front-knee-valgus) | -0.040 | -0.035 | -0.028 | -0.021 | -0.014 | -0.008 | -0.006 | × height |
| [Max Back Knee Valgus (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/max-back-knee-valgus) | -0.022 | -0.020 | -0.015 | -0.011 | -0.007 | -0.005 | -0.004 | × height |

### Cocking and Acceleration Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Cocking Phase Max Shoulder External Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-external-rotation) | 155 | 167 | 174 | 183 | 191 | 196 | 199 | deg |
| [Cocking Phase Shoulder Hyperangulation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-hyperangulation) | 132 | 141 | 149 | 158 | 165 | 174 | 181 | deg |
| [Cocking Phase Max X Factor](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-max-x-factor) | 0 | 3 | 9 | 17 | 24 | 33 | 36 | deg |
| [Cocking Phase Shoulder Horizontal Abduction](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/cocking-phase-shoulder-horizontal-abduction) | 60 | 72 | 86 | 95 | 101 | 107 | 110 | deg |
| [Acceleration Phase Max Knee Extension Velocity Front Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-knee-extension-velocity) | 251 | 272 | 307 | 345 | 389 | 428 | 440 | deg/s |
| [Acceleration Phase Max Knee Extension Velocity Back Leg](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-knee-extension-velocity) | 211 | 250 | 312 | 359 | 396 | 430 | 448 | deg/s |
| [Acceleration Phase Max Elbow Extension Velocity](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/acceleration-phase-elbow-extension-velocity) | 787 | 902 | 1049 | 1136 | 1220 | 1312 | 1352 | deg/s |

### Contact Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Contact Phase Elbow Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-elbow-flexion) | 25 | 28 | 34 | 41 | 49 | 57 | 63 | deg |
| [Contact Phase Shoulder Abduction](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-shoulder-abduction) | 106 | 112 | 122 | 129 | 138 | 144 | 147 | deg |
| [Contact Phase X Factor](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-x-factor) | -5 | -3 | 1 | 5 | 10 | 15 | 18 | deg |
| [Contact Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-tilt) | 23 | 27 | 31 | 35 | 39 | 43 | 46 | deg |
| [Time to Contact](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/time-to-contact) | 0.31 | 0.67 | 0.82 | 0.94 | 1.03 | 1.12 | 1.18 | s |
| [Contact Phase Trunk Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-flexion) | -2 | 1 | 6 | 10 | 15 | 21 | 28 | deg |
| [Contact Phase Trunk Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-trunk-rotation) | -53 | -45 | -37 | -30 | -21 | -10 | -5 | deg |
| [Contact Phase Pelvis Rotation](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-pelvis-rotation) | -66 | -51 | -42 | -37 | -31 | -23 | -19 | deg |
| [Contact Phase Wrist Height (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-wrist-height-normalized) | 1.15 | 1.18 | 1.21 | 1.24 | 1.26 | 1.28 | 1.29 | × height |
| [Contact Phase Wrist Velocity (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/contact-phase-wrist-velocity-normalized) | 704 | 745 | 813 | 843 | 869 | 899 | 917 | unconfirmed |

### Landing Phase

Deviations from center indicate atypical positioning, not necessarily poor performance.

| Variable | 5% | 10% | 25% | 50% | 75% | 90% | 95% | Units |
| - | :-: | :-: | :-: | :-: | :-: | :-: | :-: | - |
| [Finish Phase Trunk Flexion](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/finish-phase-trunk-flexion) | 29 | 35 | 42 | 48 | 55 | 61 | 65 | deg |
| [Finish Phase Trunk Tilt](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/finish-phase-trunk-tilt) | -16 | -12 | -7 | -1 | 5 | 11 | 14 | deg |
| [Forward Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-forward) | 0.065 | 0.160 | 0.261 | 0.362 | 0.446 | 0.519 | 0.574 | × height |
| [Open-Side Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-open-side) | -0.037 | 0.000 | 0.073 | 0.169 | 0.277 | 0.354 | 0.411 | × height |
| [Vertical Displacement (Normalized)](https://docs.uplift.ai/biomechanics/activities/tennis/metrics/displacement-vertical) | 0.108 | 0.117 | 0.130 | 0.154 | 0.179 | 0.200 | 0.237 | × height |


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