SFMA Back Bend
Biomechanical analysis of SFMA back bend movement assessment, including shoulder flexion and hip extension range of motion.
SFMA Back Bend
Overview
The SFMA (Selective Functional Movement Assessment) back bend assessment evaluates the range of motion and quality of movement in the spine during backward bending. This assessment measures the ability to achieve sufficient shoulder flexion and hip extension while maintaining proper alignment and identifying any compensations.Discrete Metrics
| Metric | Data Type | Units | Description |
|---|---|---|---|
| MaxShoulderFlexion | Float | degrees | Maximum shoulder flexion angle (average of left & right) |
| ShoulderFlexionROM | Float | degrees | Range of shoulder flexion motion (average of left & right) |
| MaxHipExtension | Float | degrees | Maximum hip extension angle (average of left & right) |
| HipsPassToes | Boolean | - | Whether hips move forward past toes |
| ShouldersPassHeels | Boolean | - | Whether shoulders move backward past heels |
| HipsToToesDistance | Float | meters | Horizontal distance from hips to toes at maximum reach. Positive value indicates reaching past mark, negative value indicates insufficient reach. |
| ShouldersToHeelsDistance | Float | meters | Horizaontal distance from shoulders to heels at maximum reach. Positive value indicates reaching past mark, negative value indicates insufficient reach. |
| ShoulderCompensation | Boolean | - | Whether shoulder compensation occurred (> 10° reduction in shoulder flexion) |
| Functional | Boolean | - | Whether movement is functional (meets all criteria) |
Notes
- All angular measurements follow ISB conventions
- Kinematic data typically captured at 240Hz for stability activities
- Functional movement requires:
- Shoulder flexion ROM ≥ 165°
- Hips pass in front of toes
- Shoulders pass behind heels
- No shoulder compensation (a 10° reduction in shoulder flexion when nearing peak extension)