However, it is also possible that pressures in the cross-back orientation measured by Bowles and Steele [5] were falsely high due to overly tight straps.
The standard width strap design in the cross-back orientation (left) and the wide strap design in the vertical strap orientation (right).
The significantly lower strap discomfort and the strap preference of the vertical orientation compared to the cross-back orientation were also in contrast to previous research [5].
Here, a double-stranded oligonucleotide consisting of two primer sequences in back-to-back orientation was designed as an adapter for LM-PCR.
Although the mean static and dynamic mean peak pressure data were not significantly lower in the vertical bra strap orientation compared to the cross-back orientation, participants consistently reported that the vertical orientation did not 'dig in' or 'create pressure or tension on the trapezius muscle' compared to the cross-back orientation.
The higher strap pressures in the cross-back orientation may also have been due to tighter straps in this orientation because the bra straps used in the study were commercially available convertible straps, which do not always allow for the greater distance required between the attachment sites of the bra in the cross-back orientation compared to the vertical orientation.
That is, the straps used by Bowles and Steele [5] were commercially available convertible bra straps of a fixed length, which did not allow for the additional length required to traverse the torso in the cross-back orientation.
It is also recognised that a range of reasons can affect bra strap preference, such as aesthetics and personal preference, which may have resulted in the cross-back orientation being the preferred orientation in the study cohort.
It is also conflicting that the cross-back orientation was the most preferred by the 14 participants when it had the same level of discomfort as the vertical orientation and higher strap pressures.
That is, in the vertical orientation, the strap lays across the bone, which is better designed to tolerate compressive forces relative to the muscle tissue at the cross-back orientation strap/pressure sensor interface (upper trapezius muscle) [28].
