[Dumbbell Bulgarian Split Squat (Left Leg Bias)]

Total Reps: 11 | Estimated Load: 20kg Total (2x 10kg Dumbbells)

1. Summary

Melissa, the intensity here is commendable, specifically the neuromuscular drive to push through failure on the final rep. However, biomechanically, you are trading spinal stability for concentric output in the final 20% of the set. Your "canister" (rib cage stacked over pelvis) breaks open at Rep 9, leading to lumbar hyperextension to compensate for glute fatigue. With a scoliotic spine, grinding out reps where the primary mover (glute/quad) has handed the load off to the lumbar erectors is a high-risk strategy.

2. Scores & Set Quality

| Metric | Score (1-10) | Notes |

| :--- | :---: | :--- |

| Overall Form | 7/10 | Reps 1-8 were textbook; Reps 9-11 introduced significant shear risk. |

| Spinal Integrity | 6/10 | Loss of anterior core tension leads to "rib flare" and lumbar extension under load. |

| Symmetry | 8/10 | No major valgus collapse; hips remain relatively square until failure. |

| Tempo Control | 9/10 | Excellent eccentric control (2-3s average) until severe fatigue onset. |

| Range of Motion | 10/10 | Knee flexion is deep; full elongation of the glute max is achieved. |

Set Metrics:

RPE: 10 (Maximal Effort / Technical Failure exceeded)
Fatigue Pattern: Gradual decline followed by sudden stability breakdown at Rep 9.
Form Breakdown Rep: Rep 9 (Lumbar compensation begins).
Rep Classification: [1-8] Good, [9-10] Grind, [11] Technical Failure (Completed but hazardous).

3. Rep-by-Rep Analysis

| :--: | :--: | :--: | :--: | :--: | :--- |

| 1 | 2.5s | 1.0s | 10 | 10 | Perfect stacking; tension maintained. |

| 2 | 2.2s | 1.0s | 10 | 10 | Consistent trajectory. |

| 3 | 2.1s | 1.0s | 10 | 10 | Fluid reversal at the bottom. |

| 4 | 2.3s | 1.1s | 10 | 10 | Stable. |

| 5 | 2.4s | 1.1s | 10 | 9 | Slight cervical extension (neck looking up). |

| 6 | 2.4s | 1.2s | 10 | 9 | Velocity begins to decrease. |

| 7 | 2.5s | 1.3s | 10 | 9 | Core bracing visibly challenged. |

| 8 | 2.5s | 1.5s | 10 | 8 | Hip drive slowing; chest starts to rise *after* hips. |

| 9 | 2.6s | 1.8s | 10 | 6 | Breakdown: Rib flare prominent. Lumbar extension initiates drive. |

| 10 | 2.8s | 2.2s | 10 | 5 | Significant "Good Morning" mechanics; excessive forward lean. |

| 11 | 3.0s | 4.5s | 10 | 3 | Critical: Complete loss of stack. Massive grind. Cervical craning. |

4. Biomechanical Details

Joint Angles & Range

Knee: ~135° flexion at bottom (Optimal). Full extension at lockout.
Hip: ~110-120° flexion at bottom. You are achieving maximum glute lengthening.
Ankle: ~20-25° dorsiflexion. Heel remains planted; mobility is sufficient.
Spine: Starts neutral. Progresses to Lumbar Hyperextension (Lordosis increases) significantly from Rep 9 onwards.

Asymmetries

Dominant Side: Left leg drive appears strong, but glute medius stability wavers at the very end.
Imbalances:
Pelvic Tilt: As fatigue sets in, you shift into Anterior Pelvic Tilt (APT) to mechanically shorten the hip flexors and leverage the lower back. This is a common compensation pattern but dangerous for scoliosis.

5. Scoliosis Analysis

Risk Level: Moderate to High (specifically on reps 9-11)

Curvature Flags:
Extension Intolerance: Your failure mechanic involves dumping the pelvis forward and arching the back. If your scoliotic curve involves any rotation, adding axial compression + shear force (from the forward lean) + hyperextension is the "perfect storm" for facet joint irritation.
Rib Flare: At [0:46] and [0:58], your rib cage disconnects from the pelvis. This suggests you are relying on the *passive* structures of the spine (ligaments/facets) rather than *active* Intra-Abdominal Pressure (IAP) to stabilize the load.

Adaptations:
You must constrain your Range of Motion (ROM) or Rep Count to the point where you can maintain a "Ribs Down" position. Once the ribs flare, the set is over for your spine, even if your legs have gas left.

6. Actionable Feedback

🛑 MUST DO (Safety Critical)

KILL THE SET AT REP 9: You have reached *Technical Failure* at rep 9. Reps 10 and 11 provided minimal hypertrophy stimulus relative to the exponential increase in spinal shear force. Do not grind through lumbar extension.
Pack the Neck: Stop looking up at the ceiling when it gets hard (seen clearly at 0:58). Cervical extension reflexively triggers lumbar extension. Keep your chin tucked (double chin cue) to facilitate a neutral thoracic and lumbar spine.

🔧 PERFORMANCE (Technique Fixes)

Sync Hips and Chest: On the concentric drive of the last 3 reps, your hips shoot up first, turning the movement into a split-stance Good Morning. Visualize a string pulling your chest and hips up at the exact same speed.
Re-Brace at Top: Between Reps 9 and 10, you took a breath but didn't clamp the ribs down. Exhale fully to drop ribs, inhale into the back (360° expansion), *then* descend.

💡 COULD DO (Optimization)

Slightly Shorter Stance: Your stance is quite long. Bringing the front foot back 2 inches might reduce the demand on the rear hip flexor and make it easier for you to maintain a neutral pelvis, keeping the load on the front quad/glute rather than the lumbar spine.

7. Key Moments (Timestamps)

| Time | Severity | Event / Observation |