--- id: side_lateral_raise name: Side Lateral Raise status: complete category: exercise pattern: [isolation] equipment: [dumbbell] difficulty: technical_complexity: 1 strength_prerequisite: 1 mobility_prerequisite: 1 muscles: - id: deltoid_lateral role: primary - id: deltoid_anterior role: secondary - id: deltoid_posterior role: secondary - id: supraspinatus role: secondary - id: trap_upper role: stabilizer # Multiple studies across different humeral rotation conditions. # Sweeney 2014 used bent-arm (elbow ~90°) variation at 70% 1RM → deltoid_lateral 77% ± 16.1%. # Coratella 2020 shows humeral rotation dramatically shifts anterior vs posterior delt dominance: # External rotation → anterior delt 80%; Internal rotation → posterior delt 85%. # Standard neutral position: lateral delt is primary (30–77% MVIC across studies). muscle_activation_studies: - source_id: campos_2020 doi: "10.1515/hukin-2020-0023" n: 13 population: "resistance-trained males, 60% 1RM, standard neutral" condition: load_pct_1rm: 60 implement: dumbbell phase: full_rep measurements: - {muscle: deltoid_anterior, mean_pct_mvc: 21.2, sd: null} - {muscle: deltoid_lateral, mean_pct_mvc: 30.3, sd: null} - {muscle: deltoid_posterior, mean_pct_mvc: 24.0, sd: null} - source_id: coratella_2020 doi: "10.3390/ijerph17176015" n: 10 population: "competitive bodybuilders, neutral humeral rotation" condition: load_pct_1rm: null implement: dumbbell phase: concentric notes: "Standard neutral grip" measurements: - {muscle: deltoid_anterior, mean_pct_mvc: 36.0, sd: null} - {muscle: deltoid_lateral, mean_pct_mvc: 55.0, sd: null} - {muscle: deltoid_posterior, mean_pct_mvc: 52.0, sd: null} - source_id: coratella_2020 doi: "10.3390/ijerph17176015" n: 10 population: "competitive bodybuilders, external humeral rotation" condition: load_pct_1rm: null implement: dumbbell phase: concentric notes: "Humerus externally rotated — shifts emphasis to anterior deltoid" measurements: - {muscle: deltoid_anterior, mean_pct_mvc: 80.0, sd: null} - {muscle: deltoid_lateral, mean_pct_mvc: 48.0, sd: null} - {muscle: deltoid_posterior, mean_pct_mvc: 36.0, sd: null} - source_id: coratella_2020 doi: "10.3390/ijerph17176015" n: 10 population: "competitive bodybuilders, internal humeral rotation" condition: load_pct_1rm: null implement: dumbbell phase: concentric notes: "Humerus internally rotated — shifts emphasis to posterior deltoid" measurements: - {muscle: deltoid_anterior, mean_pct_mvc: 34.0, sd: null} - {muscle: deltoid_lateral, mean_pct_mvc: 52.0, sd: null} - {muscle: deltoid_posterior, mean_pct_mvc: 85.0, sd: null} - source_id: sweeney_2014 doi: null n: 16 population: "healthy males, 70% 1RM, bent-arm variation" condition: load_pct_1rm: 70 implement: dumbbell phase: full_rep notes: "Bent-arm (elbow ~90°) reduces moment arm and allows heavier load" measurements: - {muscle: deltoid_anterior, mean_pct_mvc: 32.0, sd: 18.5} - {muscle: deltoid_lateral, mean_pct_mvc: 77.0, sd: 16.1} - {muscle: deltoid_posterior, mean_pct_mvc: 33.0, sd: 14.4} joint_rom_required: shoulder_abduction_deg: 90 source: "Sweeney 2014" strength_curve: type: ascending sticking_point: top_third peak_force_position: top notes: "Gravity moment arm increases from 0 at side to maximum at 90° abduction — resistance is lowest at the start and peaks at full parallel position" source: "Kassiano 2023" injury_risk: joint_stress: shoulder: low elbow: low common_injuries: - structure: supraspinatus_tendon mechanism: subacromial_impingement risk_factors: [internal_rotation_past_90_deg, pronated_grip_at_top, pre_existing_impingement] - structure: upper_trapezius mechanism: compensatory_shrug_under_load risk_factors: [load_too_heavy, fatigue, poor_scapular_depression_cue] contraindications: - acute_shoulder_impingement - supraspinatus_tear variations: [] progressions: [] alternatives: [cable_seated_lateral_raise] sources: - source_id: campos_2020 title: "Different Shoulder Exercises Affect the Activation of Deltoid Portions in Resistance-Trained Individuals" author: "Campos, Yuri de Almeida Costa et al." year: 2020 doi: "10.1515/hukin-2020-0023" credibility: rct - source_id: coratella_2020 title: "An Electromyographic Analysis of Lateral Raise Variations and Frontal Raise in Competitive Bodybuilders" author: "Coratella, Giuseppe et al." year: 2020 doi: "10.3390/ijerph17176015" credibility: rct - source_id: sweeney_2014 title: "Dynamite Delts: ACE Research Identifies Top Shoulder Exercises" author: "Sweeney, Samantha; Porcari, John P. et al." year: 2014 doi: null credibility: rct --- # Side Lateral Raise The side lateral raise is the primary open-chain isolation exercise for the lateral deltoid. Performed by abducting the arms from the sides to shoulder height against a dumbbell or cable load, it produces the characteristic shoulder width associated with bodybuilding aesthetics. Despite its apparent simplicity, the lateral raise is highly sensitive to humeral rotation — a single technical variable that shifts the primary load among all three deltoid heads. ## Execution 1. Stand with dumbbells at the sides, arms nearly straight (slight elbow bend to reduce joint stress) 2. Depress the scapulae before initiating — do not allow the traps to shrug as the primary movement 3. Raise the arms to approximately shoulder height (90° abduction), leading with the elbows rather than the hands 4. Keep the thumbs slightly lower than the pinkies throughout (slight internal rotation) to avoid subacromial impingement 5. Lower under control; avoid letting the weight crash back to the starting position ## What the EMG Data Shows Three independent studies establish the lateral deltoid as the primary mover in the standard neutral raise: | Study | Condition | Deltoid Lateral | Deltoid Anterior | Deltoid Posterior | |-------|-----------|-----------------|------------------|-------------------| | Campos 2020 | 60% 1RM, neutral | 30.3% | 21.2% | 24.0% | | Coratella 2020 | Neutral, bodybuilders | 55.0% | 36.0% | 52.0% | | Sweeney 2014 | 70% 1RM, bent-arm | 77.0% ± 16.1% | 32.0% ± 18.5% | 33.0% ± 14.4% | The wide range in lateral deltoid values (30–77%) reflects both load and technique differences. Sweeney 2014 used a bent-arm (elbow 90°) variation at 70% 1RM — shorter moment arm, heavier absolute load, highest values. The Campos 2020 values at 60% 1RM with full extension represent the stricter, lighter version. ## The Humeral Rotation Effect Coratella 2020 is the critical study for programming decisions. The three rotation conditions produced dramatically different activation profiles: | Rotation | Lateral Delt | Anterior Delt | Posterior Delt | |----------|--------------|---------------|----------------| | Neutral | 55% | 36% | 52% | | External | 48% | **80%** | 36% | | Internal | 52% | 34% | **85%** | External rotation primarily recruits the anterior deltoid — a muscle already well-stimulated by pressing. Internal rotation at end-range (above 90°) increases subacromial impingement risk. Keep the thumb-down position only through the middle range; do not force full internal rotation at peak. ## Cable vs Dumbbell Free-weight dumbbells have zero resistance when the arms hang at the sides and peak resistance at 90° abduction. This mismatches the deltoid's strength curve and creates a dead zone at the start. Cable variations from a low pulley provide resistance at longer deltoid lengths. See `cable_seated_lateral_raise` for cable-specific guidance. ## Variations | Variation | Key difference | Best for | |-----------|----------------|----------| | Seated lateral raise | Eliminates leg drive and momentum | Strict isolation | | Cable lateral raise | Constant tension at bottom of range | Lengthened-position loading | | Bent-arm lateral raise | Shorter moment arm; heavier load | Load progression | > For system-specific training applications, see each system's lens entry.