Overview
The side lunge is a lateral movement assessment that evaluates an athlete’s ability to step to the side with proper form, stability, and lower extremity control. This movement provides valuable information about hip abductor and adductor strength, lateral knee stability, and frontal-plane movement patterns.
Instructions
Stand with feet hip-width apart in a neutral stance. Step laterally with one leg, shifting your weight onto the stepping leg and lowering into a lateral squat while keeping the trunk upright and the opposite leg straight. Drop down as far as possible while maintaining heel contact on the stepping foot. Push back through the stepping 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 stepping leg and direction
Output Variables
Events
| Event | Short Description | Column Name |
|---|---|---|
| Initiation | Start of the lunge when the athlete begins stepping laterally. | lunge_side_initiation_frame |
| Bottom | Instant of maximum lunge depth (lowest pelvis position). | lunge_side_bottom_frame |
| End | End of the movement when the athlete returns to standing. | lunge_side_end_frame |
Phases
| Phase | Start | End |
|---|---|---|
| Eccentric (Descent) | Initiation | Bottom |
| Concentric (Ascent) | Bottom | End |
Knee Metrics
| Metric | Units | Short Description | Column Name |
|---|---|---|---|
| Right Valgus Bottom | m | Right knee medial displacement at bottom. | lunge_side_right_valgus_bottom |
| Left Valgus Bottom | m | Left knee medial displacement at bottom. | lunge_side_left_valgus_bottom |
Movement Strategy Metrics
| Metric | Units | Short Description | Column Name |
|---|---|---|---|
| Right Eccentric Hip-Knee Dominance | ratio | Right lead leg hip-knee dominance during descent (0=hip, 1=knee). | lunge_side_right_eccentric_hip_knee_dominance |
| Left Eccentric Hip-Knee Dominance | ratio | Left lead leg hip-knee dominance during descent (0=hip, 1=knee). | lunge_side_left_eccentric_hip_knee_dominance |
| Right Concentric Hip-Knee Dominance | ratio | Right lead leg hip-knee dominance during ascent (0=hip, 1=knee). | lunge_side_right_concentric_hip_knee_dominance |
| Left Concentric Hip-Knee Dominance | ratio | Left lead leg hip-knee dominance during ascent (0=hip, 1=knee). | lunge_side_left_concentric_hip_knee_dominance |
Trunk and Joint Angle Metrics
| Metric | Units | Short Description | Column Name |
|---|---|---|---|
| Max Right Trunk Lean | deg | Maximum rightward lateral trunk lean during lunge. | lunge_side_max_right_trunk_lean |
| Max Left Trunk Lean | deg | Maximum leftward lateral trunk lean during lunge. | lunge_side_max_left_trunk_lean |
| Max Right Hip Flexion Angle | deg | Maximum right hip flexion angle during lunge. | lunge_side_max_right_hip_flexion_angle |
| Max Left Hip Flexion Angle | deg | Maximum left hip flexion angle during lunge. | lunge_side_max_left_hip_flexion_angle |
| Max Right Knee Flexion Angle | deg | Maximum right knee flexion angle during lunge. | lunge_side_max_right_knee_flexion_angle |
| Max Left Knee Flexion Angle | deg | Maximum left knee flexion angle during lunge. | lunge_side_max_left_knee_flexion_angle |
| Max Right Ankle Flexion Angle | deg | Maximum right ankle dorsiflexion during lunge. | lunge_side_max_right_ankle_flexion_angle |
| Max Left Ankle Flexion Angle | deg | Maximum left ankle dorsiflexion during lunge. | lunge_side_max_left_ankle_flexion_angle |
Distance Metrics
| Metric | Units | Short Description | Column Name |
|---|---|---|---|
| Lunge Depth | m | Vertical pelvis displacement from baseline to bottom. | lunge_side_lunge_depth |
| Stance Length | m | Anterior–posterior distance between feet at bottom. | lunge_side_stance_length |
| Stance Width | m | Medial–lateral distance between feet at bottom. | lunge_side_stance_width |
Notes
- Kinematic data typically captured at 60 Hz for lunges
- Stepping 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 width is the primary distance measure for the side lunge; stance length is expected to be near zero