--- id: sumo_deadlift name: Sumo Deadlift status: complete category: exercise pattern: [hinge] equipment: [barbell] difficulty: technical_complexity: 3 strength_prerequisite: 3 mobility_prerequisite: 3 muscles: - id: erector_spinae role: primary - id: biceps_femoris role: primary - id: gluteus_maximus role: primary - id: vastus_lateralis role: primary - id: vastus_medialis role: secondary - id: semitendinosus role: secondary - id: adductor_magnus role: secondary - id: adductor_longus role: secondary - id: multifidus role: secondary - id: gastrocnemius role: secondary - id: rhomboids role: stabilizer - id: trap_upper role: stabilizer - id: forearm_flexors role: stabilizer # Hanen 2025 (doi: 10.3389/fbioe.2025.1597209): n=30, experienced male lifters, 85% 1RM. # Values are median %MVC (IQR); stored as mean_pct_mvc with sd: null. # Phase 1 = lift-off to mid-pull (knee level); Phase 2 = mid-pull to lockout. # Escamilla 2002 (doi: 10.1097/00005768-200204000-00019): n=13, collegiate football players, # 12-RM intensity. Values are mean %MVIC. # Do NOT average across studies — intensity and populations differ. muscle_activation_studies: - source_id: hanen_2025 doi: "10.3389/fbioe.2025.1597209" n: 30 population: "experienced male lifters" condition: load_pct_1rm: 85 phase: concentric stance: sumo notes: "Phase 1: lift-off to knee level" measurements: - {muscle: biceps_femoris, mean_pct_mvc: 71.3, sd: null} - {muscle: gluteus_maximus, mean_pct_mvc: 71.2, sd: null} - {muscle: vastus_lateralis, mean_pct_mvc: 63.3, sd: null} - {muscle: erector_spinae, mean_pct_mvc: 74.7, sd: null} - source_id: hanen_2025 doi: "10.3389/fbioe.2025.1597209" n: 30 population: "experienced male lifters" condition: load_pct_1rm: 85 phase: concentric stance: sumo notes: "Phase 2: knee level to lockout" measurements: - {muscle: biceps_femoris, mean_pct_mvc: 69.9, sd: null} - {muscle: gluteus_maximus, mean_pct_mvc: 74.2, sd: null} - {muscle: vastus_lateralis, mean_pct_mvc: 40.0, sd: null} - {muscle: erector_spinae, mean_pct_mvc: 67.0, sd: null} - source_id: escamilla_2002 doi: "10.1097/00005768-200204000-00019" n: 13 population: "collegiate football players" condition: load: "12-RM" phase: concentric stance: sumo measurements: - {muscle: vastus_lateralis, mean_pct_mvc: 48.0, sd: null} - {muscle: vastus_medialis, mean_pct_mvc: 44.0, sd: null} joint_rom_required: hip_flexion_deg: 39.9 knee_flexion_deg: 38.1 ankle_dorsiflexion_deg: 15.0 hip_abduction_deg: 7.9 hip_external_rotation_deg: 15.4 notes: > ROM values represent movement occurring during Phase 1 (Hanen 2025). The wide stance requires substantial hip abduction and external rotation mobility — a common limiting factor for athletes with restricted hip mobility. source: "hanen_2025" strength_curve: type: descending sticking_point: null peak_force_position: bottom notes: > Torque demands peak at lift-off. Vastus lateralis demand drops significantly from Phase 1 (63.3% MVC) to Phase 2 (40.0% MVC), confirming quadriceps dominance during the initial drive with hip extensors taking over through lockout. source: "hanen_2025" injury_risk: joint_stress: lower_back: moderate knee: moderate hip: moderate common_injuries: - structure: hip_adductors mechanism: groin_strain risk_factors: [extreme_foot_flare, inadequate_hip_mobility, rapid_load_increase] - structure: lumbar_disc mechanism: flexion_under_load risk_factors: [poor_bracing, trunk_forward_collapse] - structure: medial_knee mechanism: valgus_stress risk_factors: [knees_caving_inward, weak_hip_abductors] contraindications: - acute_hip_labral_tear - acute_groin_strain - acute_lumbar_herniation variations: [] progressions: [] alternatives: [] sources: - source_id: hanen_2025 title: "Biomechanical analysis of conventional and sumo deadlift" author: "Hanen NC, Ben Mansour K, Ertel GN, Duchene Y, Gauchard GC" year: 2025 doi: "10.3389/fbioe.2025.1597209" credibility: rct - source_id: escamilla_2002 title: "An electromyographic analysis of sumo and conventional style deadlifts" author: "Escamilla RF, Francisco AC, Kayes AV, Speer KP, Moorman CT" year: 2002 doi: "10.1097/00005768-200204000-00019" credibility: rct --- # Sumo Deadlift The sumo deadlift is a barbell hinge-pattern exercise performed with a wide foot stance — typically two to three times hip-width — and feet rotated outward approximately 40–45°. This stance positions the hips closer to the bar, producing a more upright trunk angle and a shorter moment arm from the bar to the lumbar spine compared to the conventional deadlift. ## Execution 1. Set feet very wide, near the collars of the barbell, toes flared 40–45° 2. Bend at the hips and grip the bar inside the legs with a pronated, mixed, or hook grip; arms vertical 3. Inhale and brace hard; drive the knees outward over the toes before initiating the pull 4. Drive through the floor by spreading the feet apart; keep the chest up and the bar close 5. Extend hips and knees simultaneously; lock out by driving hips into the bar at the top ## What the EMG Data Shows At 85% 1RM in experienced male lifters (Hanen 2025), the sumo deadlift shows distinct phase-specific activation: **Phase 1 (floor to knee):** Erector spinae leads at 74.7% MVC, followed closely by biceps femoris (71.3%), gluteus maximus (71.2%), and vastus lateralis (63.3%). All major posterior chain muscles are near-maximally recruited during this demanding initial drive. **Phase 2 (knee to lockout):** Gluteus maximus increases slightly to 74.2% MVC while vastus lateralis drops sharply to 40.0% MVC. The sumo deadlift transitions to a glute-dominant lockout with quadriceps contribution diminishing rapidly after bar clearance of the knees. At 12-RM intensity (Escamilla 2002), sumo VL (48% MVIC) and VM (44% MVIC) exceeds conventional (VL 40%, VM 36%), confirming greater quadriceps demand during the drive phase. Medial gastrocnemius is lower in sumo (19%) than conventional (26%) — the wider stance reduces sagittal-plane calf stabilization demand. ## Biomechanical Distinctions from Conventional Deadlift The wide stance creates two mechanical advantages: 1. **Reduced spinal moment arm**: Positioning the hips closer to the bar shortens the horizontal distance from the load to the lumbar spine, reducing shear forces on the vertebrae by roughly 8–10% compared to conventional. 2. **Multi-planar loading**: The sumo generates significantly greater frontal-plane hip abduction moments (7.9° vs 3.0° in conventional, Hanen 2025) and transverse-plane hip external rotation (15.4° vs 8.9°), recruiting hip adductors and external rotators in addition to standard sagittal-plane hip extensors. Biceps femoris and gluteus maximus peak values are comparable between sumo and conventional styles, invalidating the myth that one is categorically superior for posterior chain development. The key difference is distribution: sumo is quadriceps-dominant early in the pull; conventional maintains higher hamstring and erector demand throughout. ## Variations | Variation | Key difference | Best for | |-----------|----------------|----------| | Conventional deadlift | Narrower stance; greater trunk lean | Maximum hip extensor and erector demand | | Semi-sumo | Intermediate stance; moderate foot flare | Athletes with moderate hip mobility | > For system-specific training applications, see each system's lens entry.