An elbow brace for supporting a wearer's elbow in a desired position when using a portable electronic device to mitigate “tech neck” is made unobtrusive by incorporation into a shoulder bag having a length-adjustable shoulder strap. A flexible bag assembly comprises opposite first and second panels of flexible sheet-like material connected to define an interior compartment having a volume. An upper bag mouth is disposed between edges of the panels, with fastenings connecting its opposite ends of the edges. An elbow-receiving sleeve of flexible sheet-like material is attached in the upper bag mouth and can be opened into a generally frustoconical form, for supporting a bent elbow such that, in use, both forearm and upper arm extend from an outer end elbow-receiving sleeve. In a closed state the elbow-receiving sleeve is flattened such that opposing halves of the elbow-receiving sleeve come together.