Overview
The single leg jump is a unilateral movement assessment that evaluates an athlete’s ability to generate power and maintain stability on one leg. This movement provides valuable information about lower extremity strength, balance, and neuromuscular control.
Instructions
Stand on one leg (the stance leg as specified by footedness). Dip slightly by bending the stance knee and hip, then jump as high as possible off that leg. Land on the same leg and absorb the landing. Use the specified arm position (arm-swing or hands-on-hips) consistently. Repeat on the other leg when both sides are assessed.Dimensions
Required inputs for processing:- Arm Position: [‘arm-swing’,‘hands-on-hips’]
- Footedness: [‘left’,‘right’]
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
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 | bottom_of_jump_frame |
| 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_bottom |
| Left Valgus Bottom | meters | Left knee valgus at bottom position | left_knee_valgus_at_bottom |
| Right Valgus Landing | meters | Right knee valgus at landing | right_knee_valgus_at_landing |
| Left Valgus Landing | meters | Left knee valgus at landing | 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 | reactive_strength_index_modified |
| Right Eccentric Hip Knee Dominance | ratio | Right hip-knee dominance during eccentric phase (0=hip dominant, 1=knee dominant) | right_eccentric_hip_knee_dominance |
| Left Eccentric Hip Knee Dominance | ratio | Left hip-knee dominance during eccentric phase (0=hip dominant, 1=knee dominant) | left_eccentric_hip_knee_dominance |
| Right Concentric Hip Knee Dominance | ratio | Right hip-knee dominance during concentric phase (0=hip dominant, 1=knee dominant) | right_concentric_hip_knee_dominance |
| Left Concentric Hip Knee Dominance | ratio | Left hip-knee dominance during concentric phase (0=hip dominant, 1=knee dominant) | left_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 | “ |
| Eccentric Velocity | m/s | Average velocity during eccentric phase | “ |
| 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 |
|---|---|---|---|
| Peak Hip Flexion Takeoff | degrees | Maximum hip flexion during takeoff | jumping_hip_peak_flexion_angle |
| Peak Knee Flexion Takeoff | degrees | Maximum knee flexion during takeoff | jumping_knee_peak_flexion_angle |
| Peak Ankle Flexion Takeoff | degrees | Maximum ankle flexion during takeoff | jumping_ankle_peak_flexion_angle |
| Peak Hip Flexion Landing | degrees | Maximum hip flexion during landing | landing_hip_peak_flexion_angle |
| Peak Knee Flexion Landing | degrees | Maximum knee flexion during landing | landing_knee_peak_flexion_angle |
| Peak Ankle Flexion Landing | degrees | Maximum ankle flexion during landing | landing_ankle_peak_flexion_angle |
Joint Velocities
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Peak Hip Extension Velocity Takeoff Concentric | degrees/s | Maximum hip extension velocity during concentric phase | jumping_hip_peak_extension_velocity |
| Peak Knee Extension Velocity Takeoff Concentric | degrees/s | Maximum knee extension velocity during concentric phase | jumping_knee_peak_extension_velocity |
| Peak Ankle Extension Velocity Takeoff Concentric | degrees/s | Maximum ankle extension velocity during concentric phase | jumping_ankle_peak_extension_velocity |
| Peak Hip Flexion Velocity Landing Eccentric | degrees/s | Maximum hip flexion velocity during landing eccentric phase | landing_hip_peak_flexion_velocity |
| Peak Knee Flexion Velocity Landing Eccentric | degrees/s | Maximum knee flexion velocity during landing eccentric phase | landing_knee_peak_flexion_velocity |
| Peak Ankle Flexion Velocity Landing Eccentric | degrees/s | Maximum ankle flexion velocity during landing eccentric phase | landing_ankle_peak_flexion_velocity |
Linear Velocities
| Metric | Units | Description | Column Name |
|---|---|---|---|
| Takeoff Velocity | m/s | Vertical velocity at takeoff | takeoff_velocity |
| 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 |
Notes
- Kinematic data typically captured at 120Hz for Jumping