The grip width during a row modifies muscle recruitment: a narrow grip targets back thickness more (latissimus dorsi and middle trapezius), while a wide grip engages the middle trapezius and posterior deltoids more.

noli's read

The biomechanical analysis of muscle recruitment based on grip width is a classic topic in sports science. Studies, such as the one published in the *Journal of Electromyography and Kinesiology* (electromyographic/observational), confirm that arm position and elbow angle effectively alter tension on muscle fibers. It is established that a wide grip, by increasing arm abduction, recruits the muscles of the rear shoulder and upper back more. The claim that a narrow grip promotes 'thickness' is a bodybuilding convention rather than a strict physiological concept, but it rests on the consistent idea that the path of the elbow along the body favors the latissimus dorsi. Enzo, however, simplifies the mechanisms slightly, as recruitment is rarely exclusive: almost all back muscles work in both variants. The analysis is therefore scientifically consistent in its practical intent, even if it simplifies muscle activations that are always collaborative.

the sources

No named source held this one up — that absence is part of the verdict.