The back muscles are located along the entire backside of the body, from the base of the spine to the back of the neck.
This group of muscles is responsible for posture control, pulling, and lifting objects, and are often trained at a variety of angles.
A strong back not only helps to increase overall strength, but it can contribute to a more v-shaped physique, more defined back muscles, and a healthier posture.
When training “back”, workouts typically will target the below back muscles:
Latissimus Dorsi (Lats)
The lats are a large muscle group that spans the entire back. They run from the base of the spine (at the hips) to the back of the shoulders, in a “V” shape.
Due to the angles of attachment (diagonal) of the muscle fibres, the back needs to be targeted with both horizontal and vertical pulling movements.
Horizontal pulling movements are typically any type or row (45-90 degrees bent over row).
Vertical pulling movements are any movement where the arms are overhead and pulling towards the body (pull-ups, lat pulldowns).
Due to the fact that there are not any vertical pulling exercises you can do with dumbbells, developing a balanced back will be challenging. This is why mastering pull-ups is key.
Trapezius (Traps)
The traps run along the entire spine (up the middle of the back), and span out across the upper back and shoulders (and back of the neck).
The upper traps are most visible (top of the shoulders/back of the neck), whereas the lower and middle traps lie underneath the lats and are much less visible.
To target the upper traps, lifters rely on shrugging movements, whereas the middle and lower traps are often indirectly trained during most back exercises (and are therefore not usually needed to be trained directly).
Rhomboids and Scapular Stabilizers
These muscles can be found around and in between the shoulder blades, and are responsible for stabilising the shoulder blades and providing support as they move (which protects the shoulders)
Training these small muscle groups often is done indirectly through training the back, however, sometimes you will need to isolate them with more target exercises (such as Y raises) or focus harder on contracting them during other movements (such as squeezing the shoulder blades together during rows)
Serratus
The serratus muscle runs underneath the armpit on a diagonal angle. This helps stabilize the shoulder blades but also assists in both pressing and pulling movements.
Targeting this muscle is done by exercises such as straight arm pulldowns (cables) or pullovers.
In dumbbell-only workouts, dumbbell pullovers will be your only serratus-focused movements, and also the closest you will be able to get to training the lats from a vertical angle.
Erectors (Lower Back)
The erectors run vertically along the lower back and are responsible for extending the trunk. Additionally, these muscles help to provide stability and support during most movements to ensure the spine does not flex or bend under loads.
Most bent-over rows, deadlifts, and squats will train the lower back, however when looking to truly isolate these muscle fibres with dumbbells (and not just train the legs in the process), then you will need to look at doing dumbbell flexion rows or bent over rows in which your back is parallel to the floor (90 degrees).