Dumbbell Lying One Arm Rear Lateral Raise exercise animation (Male)

Dumbbell Lying One Arm Rear Lateral Raise

Target muscle
Deltoid Posterior
Synergist muscles
Deltoid Lateral, Infraspinatus, Teres Minor, Trapezius Lower Fibers, Trapezius Middle Fibers
Equipment
Dumbbell
Body part
Shoulders
Type
Strength

The dumbbell lying one arm rear lateral raise is an isolation exercise for the rear deltoid (posterior deltoid), performed one arm at a time while lying chest-down on a flat bench or on your side. The rear delt does the lifting, with the lateral deltoid, infraspinatus, teres minor, and the lower and middle trapezius assisting. It builds the often-neglected back of the shoulder for better posture and balanced delts.

How to do the Dumbbell Lying One Arm Rear Lateral Raise

  1. 1Lie chest-down on a flat bench (or on your side) holding a single dumbbell in one hand, letting your arm hang straight down toward the floor.
  2. 2Turn your palm to face the bench (neutral or slightly down) and keep a soft, fixed bend of about 10–20° in your elbow.
  3. 3Brace your core and pull your shoulder blade gently toward your spine to set the rear delt.
  4. 4Raise the dumbbell out to the side in a wide arc until your upper arm is roughly level with your torso, leading with your elbow.
  5. 5Keep the movement slow and controlled, squeezing the back of your shoulder at the top without shrugging or twisting your torso.
  6. 6Lower the dumbbell under control along the same path back to the start, resisting gravity the whole way.
  7. 7Complete all your reps on one side, then switch the dumbbell to the other hand and repeat.

Form tips

  • Use a light weight and focus on feeling the rear delt working — this is a small muscle that responds to control, not heavy load.
  • Lead the lift with your elbow rather than your hand to keep tension on the rear delt instead of recruiting the traps.
  • Pause briefly at the top of each rep to maximize the contraction in the back of the shoulder.
  • Keep your neck relaxed and your gaze down so you don't tense your upper traps as you raise the weight.

Common mistakes

  • Swinging or using momentum to throw the dumbbell up, which shifts the work off the rear delt and onto your back and shoulder joint.
  • Going too heavy, which forces you to shrug and rotate the torso and turns the lift into a row instead of a rear-delt raise.
  • Bending and straightening the elbow during the rep, which turns it into a triceps movement and loses tension on the target muscle.
  • Raising the arm well above torso level, which hands the load to the traps and stresses the shoulder rather than isolating the rear delt.

Frequently asked questions

What muscles does the dumbbell lying one arm rear lateral raise work?

It primarily targets the rear (posterior) deltoid, with the lateral deltoid, infraspinatus, teres minor, and the lower and middle trapezius assisting as synergists.

Why do this exercise one arm at a time?

Working a single arm lets you focus fully on the rear delt, fix side-to-side imbalances, and use a full range of motion without your stronger side compensating.

How many sets and reps should I do?

Because the rear delt is a small muscle that favors control over heavy load, 3–4 sets of 12–20 reps per arm with a light dumbbell works well.

What's a good alternative to the lying one arm rear lateral raise?

The bent-over dumbbell reverse fly trains the same rear delt with both arms at once, and reverse pec deck or face pulls are solid machine and cable options.

Where should I feel this exercise?

You should feel it in the back of your shoulder. If you feel it mainly in your upper traps or lower back, lighten the load and lead with your elbow.

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