> ## 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.

# Track and Field: Shot Put

> Biomechanical analysis of shot put throw movements, including events, phases, and discrete metrics.

## Overview

The shot put is a track and field throwing event in which the athlete accelerates a metal ball (the shot) across the throwing circle — using either a glide or spin technique — before releasing it from the shoulder with full extension of the throwing arm.
The thrower drives across the circle with the legs and hips, transferring momentum through the trunk into the arm, and releases the shot at an angle that balances height and distance.
Distance depends on release speed, release angle and height, and how efficiently the lower body's momentum transfers into the throw.

Biomechanical analysis of the shot put can address foot-off and foot-down timing across the circle, trunk and hip-shoulder separation, arm position and trunk lean at release, and release speed, height, and angle.

## Dimensions

Required inputs for processing are not yet defined. When supported, typical dimensions may include:

* **handedness:** the handedness of the athlete \['left', 'right'], which determines throw direction and rotation

## Output Variables

### Generic Outputs

Every capture includes session metadata, standard joint angle/velocity time series, and 3D keypoint positions common to all movements. See [Generic Outputs](/biomechanics/activities/generic_outputs) for the full list.

### Events

| Metric                | Acronym | Description                                               |
| --------------------- | ------- | --------------------------------------------------------- |
| Dominant Foot Off     | DFO     | the instance when the dominant foot leaves the ground     |
| NonDominant Foot Off  | NDFO    | the instance when the nondominant foot leaves the ground  |
| Dominant Foot Down    | DFD     | the instance when the dominant foot touches the ground    |
| NonDominant Foot Down | NDFD    | the instance when the nondominant foot touches the ground |
| Release               | R       | release of the shot                                       |

### Phases and Stages of the Shot Put

| Phase      | Start | End  |
| ---------- | ----- | ---- |
| Entry      | DFO   | NDFO |
| Airborne   | NDFO  | DFD  |
| Transition | DFD   | NDFD |
| Delivery   | NDFD  | R    |

### Discrete Metrics

| Metric                             | Units   | Description                                                              |
| ---------------------------------- | ------- | ------------------------------------------------------------------------ |
| Handedness                         | N/A     | Calculated handedness of the athlete ('right' or 'left')                 |
| Entry Phase                        | seconds | Time between dominant foot off and non-dominant foot off                 |
| Airborne Phase                     | seconds | Time between non-dominant foot off and dominant foot down                |
| Transition Phase                   | seconds | Time between dominant foot down and non-dominant foot down               |
| Delivery Phase                     | seconds | Time between non-dominant foot down and release                          |
| Height at DFO                      | meters  | Height of the shot at dominant foot off                                  |
| Height at NDFO                     | meters  | Height of the shot at non-dominant foot off                              |
| Height at DFD                      | meters  | Height of the shot at dominant foot down                                 |
| Height at NDFD                     | meters  | Height of the shot at non-dominant foot down                             |
| Height at Release                  | meters  | Height of the shot at release                                            |
| Speed at DFO                       | m/s     | Speed of the shot at dominant foot off                                   |
| Speed at NDFO                      | m/s     | Speed of the shot at non-dominant foot off                               |
| Speed at DFD                       | m/s     | Speed of the shot at dominant foot down                                  |
| Speed at NDFD                      | m/s     | Speed of the shot at non-dominant foot down                              |
| Speed at Release                   | m/s     | Speed of the shot at release                                             |
| Path Length                        | meters  | Total path length of the shot from DFO to release                        |
| Release Angle                      | degrees | Angle of shot trajectory at release                                      |
| Airborne Phase Distance            | meters  | Distance travelled by pelvis during airborne phase                       |
| Base of Support Width              | meters  | Width between ankles at non-dominant foot down                           |
| Trunk Flexion at Release           | degrees | Trunk flexion angle at release (forward = positive, backward = negative) |
| Trunk Tilt at Release              | degrees | Trunk tilt angle at release                                              |
| Hip-Shoulder Separation at Release | degrees | Angle between hips and shoulders at release                              |
| Distance                           | meters  | Estimated distance thrown                                                |

## Notes

* Kinematic data typically captured at 240Hz