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.
Overview
The forward lunge is a fundamental movement assessment that evaluates an athlete’s ability to perform a stepping motion with proper form and stability.
This movement is commonly used in athletic assessment and training as it provides valuable information about lower extremity strength, balance, and movement patterns.
Instructions
Stand with feet hip-width apart in a neutral stance.
Step forward with one leg, lowering the back knee toward the ground while keeping the trunk upright.
Drop down as far as possible, being careful to not slam your rear knee into the ground.
Push back through the front foot to return to the starting position.
Perform at a natural, controlled pace without pausing at the bottom.
Dimensions
Required inputs for processing:
- Footedness: [‘right’, ‘left’] — indicates the lead (stepping) leg
Output Variables
Events
| Metric | Description | Column Name |
|---|
| Initiation | The start of the lunge when the athlete begins stepping forward | lunge_forward_initiation_frame |
| Bottom | The instant of maximum lunge depth (lowest pelvis position) | lunge_forward_bottom_frame |
| End | The end of the movement when the athlete returns to standing | lunge_forward_end_frame |
Phases
| Phase | Start | End |
|---|
| Eccentric (Descent) | Initiation | Bottom |
| Concentric (Ascent) | Bottom | End |
Knee Metrics
| Metric | Units | Description | Column Name |
|---|
| Right Valgus Bottom | meters | Right knee medial displacement at bottom position | lunge_forward_right_valgus_bottom |
| Left Valgus Bottom | meters | Left knee medial displacement at bottom position | lunge_forward_left_valgus_bottom |
Movement Strategy Metrics
| Metric | Units | Description | Column Name |
|---|
| Right Eccentric Hip-Knee Dominance | ratio | Right lead leg hip-knee dominance during descent (0=hip, 1=knee) | lunge_forward_right_eccentric_hip_knee_dominance |
| Left Eccentric Hip-Knee Dominance | ratio | Left lead leg hip-knee dominance during descent (0=hip, 1=knee) | lunge_forward_left_eccentric_hip_knee_dominance |
| Right Concentric Hip-Knee Dominance | ratio | Right lead leg hip-knee dominance during ascent (0=hip, 1=knee) | lunge_forward_right_concentric_hip_knee_dominance |
| Left Concentric Hip-Knee Dominance | ratio | Left lead leg hip-knee dominance during ascent (0=hip, 1=knee) | lunge_forward_left_concentric_hip_knee_dominance |
Trunk and Joint Angle Metrics
| Metric | Units | Description | Column Name |
|---|
| Max Right Trunk Lean | degrees | Maximum rightward lateral trunk lean during lunge | lunge_forward_max_right_trunk_lean |
| Max Left Trunk Lean | degrees | Maximum leftward lateral trunk lean during lunge | lunge_forward_max_left_trunk_lean |
| Max Right Hip Flexion Angle | degrees | Maximum right hip flexion angle during lunge | lunge_forward_max_right_hip_flexion_angle |
| Max Left Hip Flexion Angle | degrees | Maximum left hip flexion angle during lunge | lunge_forward_max_left_hip_flexion_angle |
| Max Right Knee Flexion Angle | degrees | Maximum right knee flexion angle during lunge | lunge_forward_max_right_knee_flexion_angle |
| Max Left Knee Flexion Angle | degrees | Maximum left knee flexion angle during lunge | lunge_forward_max_left_knee_flexion_angle |
| Max Right Ankle Flexion Angle | degrees | Maximum right ankle dorsiflexion during lunge | lunge_forward_max_right_ankle_flexion_angle |
| Max Left Ankle Flexion Angle | degrees | Maximum left ankle dorsiflexion during lunge | lunge_forward_max_left_ankle_flexion_angle |
Distance Metrics
| Metric | Units | Description | Column Name |
|---|
| Lunge Depth | meters | Vertical pelvis displacement from baseline to bottom | lunge_forward_lunge_depth |
| Stance Length | meters | Anterior–posterior distance between feet at bottom | lunge_forward_stance_length |
| Stance Width | meters | Medial–lateral distance between feet at bottom | lunge_forward_stance_width |
Notes
- Kinematic data typically captured at 60 Hz for lunging
- Lead leg metrics (valgus, hip-knee dominance) are reported for the stepping leg only; the non-lead side is set to NaN
- Trunk and joint angle metrics are computed over the full lunge window (Initiation to End)
- Stance dimensions are measured at the Bottom event, normalized to pelvis orientation
