SFMA Squat
Biomechanical analysis of SFMA squat movements, including events, phases, and discrete metrics.
Overview
The SFMA (Selective Functional Movement Assessment) squat is one of seven fundamental movement patterns assessed in individuals experiencing musculoskeletal pain. Unlike a generic squat, the SFMA squat is not just about performing the movement, but about observing its quality and identifying underlying dysfunction. The SFMA squat involves standing with feet shoulder-width apart, toes facing forward, and arms extended forward with palms facing down. The individual then slowly descends as deep as possible into a squat position, aiming to keep heels on the floor, and head and chest facing forward. At the bottom, swing the arms down and back while keeping elbows extended, bringing your hands as close to the floor as possible. Then swing the arms back forward and stand back up to complete the movement. The assessment is highly qualitative, with trained clinicians often observing for specific deviations and compensations. The goal is to determine if any limitations are due to:- Mobility issues: Problems with joint range of motion (e.g., tight ankles, hips, or thoracic spine) or tissue extensibility (e.g., tight muscles).
- Stability/motor control issues: Difficulties with neuromuscular coordination, muscle activation, or maintaining control throughout the movement.
Dimensions
Required inputs for processing:- None
Events
| Metric | Data Type | Description | Column Name |
|---|---|---|---|
| Initiation | Int | the start of the squat | “ |
| Bottom1 | Int | the first instance of maximum squat depth | “ |
| Bottom | Int | the instant of maximum squat depth | “ |
| Ascent Start | Int | the start of upward movement | “ |
| End | Int | the end of the movement | “ |
Discrete Metrics
| Metric | Data Type | Units | Description | Column Name |
|---|---|---|---|---|
| Depth | Float | meters | Vertical displacement of pelvis from start to bottom | squat_depth |
| Maximum Trunk Angle | Float | degrees | Maximum trunk angle relative to vertical | sfma_squat_trunk_peak_angle |
| Maximum Left Hip Angle | Float | degrees | Maximum left hip flexion angle | sfma_squat_left_hip_peak_angle |
| Maximum Right Hip Angle | Float | degrees | Maximum right hip flexion angle | sfma_squat_right_hip_peak_angle |
| Maximum Left Knee Angle | Float | degrees | Maximum left knee flexion angle | sfma_squat_left_knee_peak_angle |
| Maximum Right Knee Angle | Float | degrees | Maximum right knee flexion angle | sfma_squat_right_knee_peak_angle |
| Maximum Left Ankle Angle | Float | degrees | Maximum left ankle flexion angle | sfma_squat_left_ankle_peak_angle |
| Maximum Right Ankle Angle | Float | degrees | Maximum right ankle flexion angle | sfma_squat_right_ankle_peak_angle |
| Wrists Pass Ankles | Int | N/A | Whether wrists move beyond ankles (1) or not (0) | sfma_squat_wrists_pass_ankles |
| Wrists Pass Ankles Distance | Float | meters | Distance between wrists and ankles at maximum wrist height | “ |
| Hips Pass Knees | Int | N/A | Whether hips go below knees (1) or not (0) | sfma_squat_hips_pass_knees |
| Hips Pass Knees Distance | Float | meters | Distance between hips and knees at maximum hip depth | “ |
| Functional | Int | N/A | Whether movement is functional (1) or not (0) based on whether both hips pass knees and wrists pass ankles | sfma_squat_functional |
Notes
- Kinematic data typically captured at 120Hz for Squatting