Overview
The squat jump is a fundamental movement assessment that involves jumping from a static squat position without a countermovement. This movement is commonly used in athletic assessment and training as it provides valuable information about an athlete’s explosive power and lower extremity function.
Instructions
Start in a squat position with knees bent (typically to about 90°). Hold briefly without moving, then jump as high as possible without any preliminary dip. Land softly on both feet. Use the specified arm position (arm-swing or hands-on-hips) consistently for the trial.Dimensions
Required inputs for processing:- Arm Position: [‘arm-swing’,‘hands-on-hips’]
Phases of the Jump
| Phase | Start | End |
|---|---|---|
| Jumping | Initiation | Takeoff |
| Jumping Eccentric | Initiation | Bottom |
| Jumping Concentric | Bottom | Takeoff |
| Landing | Landing | Termination |
| Landing Eccentric | Landing | Landing Bottom |
| Landing Concentric | Landing Bottom | Termination |
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 for the full list.Events
| Event | Description | Column Name |
|---|---|---|
| Initiation | the start of the jump - when the person begins to move downward | jump_initiation_frame |
| Bottom | the lowest point of the pelvis before the jump | “ |
| Takeoff | the instant of leaving the ground | takeoff_frame |
| Peak Height | the instant when maximum height reached | “ |
| Landing | the instant of ground contact | jump_landing_frame |
| Landing Bottom | the lowest point of the pelvis after the jump | “ |
| Termination | end of the movement - when the person returns to normal standing position | “ |
Distance Metrics
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Jump Height | meters | Maximum height reached during the jump | jump_height |
| Right Valgus Bottom | meters | Right knee valgus at bottom position | right_knee_valgus_at_landing |
| Left Valgus Bottom | meters | Left knee valgus at bottom position | left_knee_valgus_at_landing |
| Right Valgus Landing | meters | Right knee valgus at landing | “ |
| Left Valgus Landing | meters | Left knee valgus at landing | “ |
| Right Valgus Landing Bottom | meters | Right knee valgus at landing bottom | right_knee_valgus_at_landing_bottom |
| Left Valgus Landing Bottom | meters | Left knee valgus at landing bottom | left_knee_valgus_at_landing_bottom |
| Right Valgus Landing Full | meters | Maximum right knee valgus during landing | “ |
| Left Valgus Landing Full | meters | Maximum left knee valgus during landing | “ |
| Right Displacement | meters | Lateral displacement during landing | “ |
| Forward Displacement | meters | Forward displacement during landing | “ |
Movement Flags and Other Metrics
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Knees Track | binary | Binary indicator if knees track properly (1=yes, 0=no) | “ |
| Hips Feet Stationary | binary | Binary indicator if hips and feet remain stationary | “ |
| High Jump Height | binary | Binary indicator if jump height exceeds 14 inches | “ |
| Stiff Knee Landing | binary | Binary indicator of stiff knee landing | “ |
| Flight Time | seconds | Time from takeoff to landing | “ |
| RSI Mod | N/A | Reactive Strength Index Modified | “ |
| Eccentric Hip Knee Dominance | ratio | Hip-knee dominance during eccentric phase (0=hip dominant, 1=knee dominant) | “ |
| Concentric Hip Knee Dominance | ratio | Hip-knee dominance during concentric phase (0=hip dominant, 1=knee dominant) | concentric_hip_knee_dominance |
| Landing Hip Knee Dominance | ratio | Hip-knee dominance during landing phase (0=hip dominant, 1=knee dominant) | landing_hip_knee_dominance |
| Landing Stiffness Index | N/A | Index of landing stiffness | “ |
| Landing Stiffness Index Level | N/A | Classification of landing stiffness | “ |
| Kinematic Sequence | N/A | Sequence of peak velocities during the jump | “ |
| Kinematic Sequence Array | N/A | Array representation of kinematic sequence | “ |
Joint Angles
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Left Peak Hip Flexion Takeoff | degrees | Maximum left hip flexion during takeoff | jumping_left_hip_peak_flexion_angle |
| Right Peak Hip Flexion Takeoff | degrees | Maximum right hip flexion during takeoff | jumping_right_hip_peak_flexion_angle |
| Left Peak Knee Flexion Takeoff | degrees | Maximum left knee flexion during takeoff | jumping_left_knee_peak_flexion_angle |
| Right Peak Knee Flexion Takeoff | degrees | Maximum right knee flexion during takeoff | jumping_right_knee_peak_flexion_angle |
| Left Peak Ankle Flexion Takeoff | degrees | Maximum left ankle flexion during takeoff | jumping_left_ankle_peak_flexion_angle |
| Right Peak Ankle Flexion Takeoff | degrees | Maximum right ankle flexion during takeoff | jumping_right_ankle_peak_flexion_angle |
| Left Peak Hip Flexion Landing | degrees | Maximum left hip flexion during landing | landing_left_hip_peak_flexion_angle |
| Right Peak Hip Flexion Landing | degrees | Maximum right hip flexion during landing | landing_right_hip_peak_flexion_angle |
| Left Peak Knee Flexion Landing | degrees | Maximum left knee flexion during landing | landing_left_knee_peak_flexion_angle |
| Right Peak Knee Flexion Landing | degrees | Maximum right knee flexion during landing | landing_right_knee_peak_flexion_angle |
| Left Peak Ankle Flexion Landing | degrees | Maximum left ankle flexion during landing | landing_left_ankle_peak_flexion_angle |
| Right Peak Ankle Flexion Landing | degrees | Maximum right ankle flexion during landing | landing_right_ankle_peak_flexion_angle |
Joint Velocities
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Left Peak Hip Flexion Velocity Takeoff Eccentric | degrees/s | Maximum left hip flexion velocity during eccentric phase | “ |
| Right Peak Hip Flexion Velocity Takeoff Eccentric | degrees/s | Maximum right hip flexion velocity during eccentric phase | “ |
| Left Peak Knee Flexion Velocity Takeoff Eccentric | degrees/s | Maximum left knee flexion velocity during eccentric phase | “ |
| Right Peak Knee Flexion Velocity Takeoff Eccentric | degrees/s | Maximum right knee flexion velocity during eccentric phase | “ |
| Left Peak Ankle Flexion Velocity Takeoff Eccentric | degrees/s | Maximum left ankle flexion velocity during eccentric phase | “ |
| Right Peak Ankle Flexion Velocity Takeoff Eccentric | degrees/s | Maximum right ankle flexion velocity during eccentric phase | “ |
| Left Peak Shoulder Flexion Velocity Takeoff Concentric | degrees/s | Maximum left shoulder flexion velocity during concentric phase | “ |
| Right Peak Shoulder Flexion Velocity Takeoff Concentric | degrees/s | Maximum right shoulder flexion velocity during concentric phase | “ |
| Left Peak Hip Extension Velocity Takeoff Concentric | degrees/s | Maximum left hip extension velocity during concentric phase | jumping_left_hip_peak_extension_velocity |
| Right Peak Hip Extension Velocity Takeoff Concentric | degrees/s | Maximum right hip extension velocity during concentric phase | jumping_right_hip_peak_extension_velocity |
| Left Peak Knee Extension Velocity Takeoff Concentric | degrees/s | Maximum left knee extension velocity during concentric phase | jumping_left_knee_peak_extension_velocity |
| Right Peak Knee Extension Velocity Takeoff Concentric | degrees/s | Maximum right knee extension velocity during concentric phase | jumping_right_knee_peak_extension_velocity |
| Left Peak Ankle Extension Velocity Takeoff Concentric | degrees/s | Maximum left ankle extension velocity during concentric phase | jumping_left_ankle_peak_extension_velocity |
| Right Peak Ankle Extension Velocity Takeoff Concentric | degrees/s | Maximum right ankle extension velocity during concentric phase | jumping_right_ankle_peak_extension_velocity |
| Left Peak Hip Flexion Velocity Landing Eccentric | degrees/s | Maximum left hip flexion velocity during landing eccentric phase | landing_left_hip_peak_flexion_velocity |
| Right Peak Hip Flexion Velocity Landing Eccentric | degrees/s | Maximum right hip flexion velocity during landing eccentric phase | landing_right_hip_peak_flexion_velocity |
| Left Peak Knee Flexion Velocity Landing Eccentric | degrees/s | Maximum left knee flexion velocity during landing eccentric phase | landing_left_knee_peak_flexion_velocity |
| Right Peak Knee Flexion Velocity Landing Eccentric | degrees/s | Maximum right knee flexion velocity during landing eccentric phase | landing_right_knee_peak_flexion_velocity |
| Left Peak Ankle Flexion Velocity Landing Eccentric | degrees/s | Maximum left ankle flexion velocity during landing eccentric phase | landing_left_ankle_peak_flexion_velocity |
| Right Peak Ankle Flexion Velocity Landing Eccentric | degrees/s | Maximum right ankle flexion velocity during landing eccentric phase | landing_right_ankle_peak_flexion_velocity |
| Left Peak Hip Extension Velocity Landing Concentric | degrees/s | Maximum left hip extension velocity during landing concentric phase | “ |
| Right Peak Hip Extension Velocity Landing Concentric | degrees/s | Maximum right hip extension velocity during landing concentric phase | “ |
| Left Peak Knee Extension Velocity Landing Concentric | degrees/s | Maximum left knee extension velocity during landing concentric phase | “ |
| Right Peak Knee Extension Velocity Landing Concentric | degrees/s | Maximum right knee extension velocity during landing concentric phase | “ |
| Left Peak Ankle Extension Velocity Landing Concentric | degrees/s | Maximum left ankle extension velocity during landing concentric phase | “ |
| Right Peak Ankle Extension Velocity Landing Concentric | degrees/s | Maximum right ankle extension velocity during landing concentric phase | “ |
Linear Velocities
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Takeoff Velocity | m/s | Vertical velocity at takeoff | takeoff_velocity |
| Eccentric Velocity | m/s | Average velocity during eccentric phase | “ |
| Peak COM Velocity Takeoff Eccentric | m/s | Maximum center of mass velocity during eccentric phase | “ |
| Peak COM Velocity Takeoff Concentric | m/s | Maximum center of mass velocity during concentric phase | jumping_com_peak_velocity |
| Peak COM Velocity Landing Eccentric | m/s | Maximum center of mass velocity during landing eccentric phase | landing_com_peak_velocity |
| Peak COM Velocity Landing Concentric | m/s | Maximum center of mass velocity during landing concentric phase | “ |
Notes
- Kinematic data typically captured at 120Hz for Jumping