Dimensions
Required Inputs for processing:- handedness: the handedness of the pitcher [‘left’, ‘right’]
Variables
Output variables from pitching analysis.Events
Automated events break down the pitch into phases or periods of interest. Many metrics occur at specific events.| Event | Description | Column Name |
|---|---|---|
| Initiation | the start of the baseball pitch | initiation_frame |
| Max Knee Raise | the maximum height of the knee during the pitch | max_knee_raise_frame |
| Low Hand | the low point of the throwing hand during the pitch | low_hand_frame |
| Foot Contact | when the front foot contacts the ground | foot_contact_frame |
| Twist | the maximum rotation of the pelvis, trunk, and arm | twist_frame |
| Peak Pelvis Angular Velocity | The instant of pelvis peak angular velocity. | peak_pelvis_velocity_frame |
| Peak Trunk Angular Velocity | The instant of trunk peak angular velocity. | peak_trunk_velocity_frame |
| Peak Arm Angular Velocity | The instant of upper arm peak angular velocity. | peak_arm_velocity_frame |
| Release | the estimated timing of ball release | ball_release_frame |
| Wrist Below Hips | when the wrist is below the hips during the pitch | wrist_below_hips_frame |
Kinematic Sequence Metrics
Assess sequencing and speeds for pitch delivery.| Metric | Units | Description | Column Name |
|---|---|---|---|
| Kinematic Sequence | N/A | Sequence of peak anngular velocities during the pitch. Correct sequence is pelvis-trunk-arm. | kinematic_sequence_order |
| Peak Pelvis Angular Velocity | deg/s | Max angular velocity (twist speed) of the pelvis segment. | peak_pelvis_angular_velocity |
| Peak Trunk Angular Velocity | deg/s | Max angular velocity (twist speed) of the trunk segment. | peak_trunk_angular_velocity |
| Peak Arm Angular Velocity | deg/s | Max angular velocity (twist speed) of the upper arm segment. | peak_arm_angular_velocity |
| Trunk to Arm Speed Up | ratio | Ratio (multiplication factor) of speed increase from trunk to arm. | trunk_to_arm_velocity_speedup |
| Pelvis to Trunk Speed Up | ratio | Ratio (multiplication factor) of speed increase from pelvis to trunk. | pelvis_to_trunk_velocity_speedup |
Movement Flaw Metrics
Movement flaws identify poor or suboptimal mechanics for timing and body positioning during the pitch.| Metric | Units | Description | Column Name |
|---|---|---|---|
| Elbow Hike | N/A | Binary indicator if elbow is above shoulder at foot contact. | elbow_hike |
| Arm Drag | N/A | Binary indicator of late arm motion, occurs if the elbow is above the wrist at foot contact. | arm_drag |
| Forearm Flyout | N/A | Binary indicator of excessive elbow extension prior to ball release. Occurs if elbow angle < 75 deg at foot contact AND < 20 deg at ball release. | forearm_flyout |
| Sway | N/A | Binary indicator of excessive backwards motion, indicated by if the front knee, midpoint of the head, or body center of mass crosses behind the back leg at max front knee raise. | sway |
| Hanging Back | N/A | Binary indicator if the pitcher initially moves backwards (away from the plate) directly after max front knee raise. | hanging_back |
| Closing Front/Back | N/A | Binary indicator of excessive trunk tilt. Occurs if the pitcher’s side-to-side trunk angle relative to pelvis deviates more than 20 degrees from vertical between max knee raise and foot contact events. | closing_front_or_back |
| Flying Open | N/A | Binary indicator of early trunk rotation. Occurs if the trunk angular velocity is peaking before foot contact and X-factor is within 5 deg of 0 at foot contact. | flying_open |
| Late Rise | N/A | Binary indicator of delayed wrist elevation (flip up), ocurring if wrist is below elbow at foot contact. | late_rise |
| Getting Out In Front | N/A | Binary indicator of early trunk forward rotation (greater than -20) at foot contact. | getting_out_in_front |
| Knee Collapse | N/A | Binary indicator of front knee bends excessively (>20 deg) between foot contact and ball release. | knee_collapse |
| High Hand | N/A | Binary indicator of whether sufficient forearm layback occurrs. If the wrist joint center does not get within 10 cm (~4 in) of the elbow joint center veritcal position during the cocking phase, then high hand is present. | high_hand |
| Early Release | N/A | Binary indicator of early ball release - indicated by wrist fore/aft position to lead toe. If wrist is behind toe at release, then its early. | early_release |
Linear Metrics & More
Show distances, positions, and speeds relevant to pitching.| Metric | Units | Description | Column Name |
|---|---|---|---|
| Stride Length | % of height | Length of stride as percentage of athlete height. Calculated between rear foot position at max knee raise and front foot position at foot contact. | stride_length |
| Max Trunk COM Velocity | m/s | Maximum linear velocity of the trunk center of mass during the pitch. | max_trunk_com_velocity |
| Wrist Position to Lead Toe | m | Wrist fore/aft position relative to the lead toe at the instant of release. Positive values indicate release in front of toe, negative values indicate behind. | wrist_fore_aft_lead_toe_at_release |
| Wrist Height at Release | m | Wrist vertical position at the instant of release, relative to rear toe height at the start of the pitch (proxy for mound level). | wrist_height_at_release |
| Handedness | N/A | Handedness of the athlete (‘right’ or ‘left’). | handedness |
| Time to Release | seconds | Time from initiation to ball release. | time_to_release |
Angular Metrics
These metrics describe joint angles and segment angles relative to global or home plate.| Metric | Units | Description | Column Name |
|---|---|---|---|
| Max X Factor | deg | max amount of hip shoulder separation before the acceleration phase | max_x_factor |
| Hip Raise Angle | deg | Maximum flexion angle of the lead hip prior to the pitch. Should occur at max knee raise event. | hip_raise_angle |
| Max Layback Angle | degrees | Maximum trunk extension angle. | max_layback_angle |
| Arm Slot Angle | deg | Abduction angle of the arm (shoulder to wrist) at ball release compared to vertical (adducted). | arm_slot_angle |
| Arm Slot Type | deg | Classification of arm slot angle. | arm_slot_type |
| Trunk Lateral Tilt at Foot Contact | degrees | Lateral trunk tilt at foot contact | trunk_lateral_tilt_at_foot_contact |
| Trunk Lateral Tilt at Release | degrees | Lateral trunk tilt at ball release. | trunk_lateral_tilt_at_ball_release |
| Trunk Forward Tilt at Release | degrees | Forward trunk tilt at ball release. | trunk_forward_tilt_at_ball_release |
| Trunk Angle to Plate Coil | deg | Trunk rotation angle relative to home plate, where facing home plate is 0 degrees. Coil is the max twist angle away from the plate prior to delivery. | trunk_angle_to_plate_coil |
| Trunk Angle to Plate Foot Contact | deg | Trunk rotation angle relative to home plate, where facing home plate is 0 degrees. This metric is the trunk angle at the instant of lead foot contact. | trunk_angle_to_plate_foot_contact |
| Trunk Angle to Plate Release | deg | Trunk rotation angle relative to home plate, where facing home plate is 0 degrees. This metric is the trunk angle at the instant of ball release. | trunk_angle_to_plate_release |
| Pelvis Angle to Plate Coil | deg | Pelvis rotation angle relative to home plate, where facing home plate is 0 degrees. Coil is the max twist angle away from the plate prior to delivery. | pelvis_angle_to_plate_coil |
| Pelvis Angle to Plate Foot Contact | deg | Pelvis rotation angle relative to home plate, where facing home plate is 0 degrees. This metric is the pelvis angle at the instant of lead foot contact. | pelvis_angle_to_plate_foot_contact |
| Pelvis Angle to Plate Release | deg | Pelvis rotation angle relative to home plate, where facing home plate is 0 degrees. This metric is the pelvis angle at the instant of ball release. | pelvis_angle_to_plate_release |
Notes
- Kinematic data typically captured at 240Hz for Baseball Pitching
- All boolean variables (true/false = 1/0) return -1 if metric unable to be calculated.