Single Leg Jump

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.

Example image of a man doing a single leg jump, bottom position

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

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	`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

Get Started

Resources

Biomechanics

Single Leg Jump

Overview

Instructions

Dimensions

Phases of the Jump

Output Variables

Generic Outputs

Events

Distance Metrics

Movement Flags and Other Metrics

Joint Angles

Joint Velocities

Linear Velocities

Notes

​Overview

​Instructions

​Dimensions

​Phases of the Jump

​Output Variables

​Generic Outputs

​Events

​Distance Metrics

​Movement Flags and Other Metrics

​Joint Angles

​Joint Velocities

​Linear Velocities

​Notes

Overview

Instructions

Dimensions

Phases of the Jump

Output Variables

Generic Outputs

Events

Distance Metrics

Movement Flags and Other Metrics

Joint Angles

Joint Velocities

Linear Velocities

Notes