Icommend the critical review of this study, and the commenter raises some good points, most important being that exhaustive research is needed to compare pad styles and sagittal plane alignment. Although just 6° difference in sagittal plane alignment resulted from pad differences, it is important to remember that this was a significant amount (p < 0.05). Attempts were made to reduce the likelihood of confounds through sample selection criteria and study design. However, considering the numerous variables not accounted for in the study (i.e., maturity status between groups, age, and variance in curve magnitude), the results may indeed have been influenced by confounds.
As for the location, size, and placement of the thoracic pads, I might clarify by saying that standard methods taught at the Boston Brace course were used. For instance, the course teaches to extend the thoracic pad up to the rib just below the apical vertebrae. The pictures included in the published article show a typical placement of both the L-pad and the PL-pad.
I think it is important to take a step back and observe the principles of force systems at work with regard to pad styles, rather than dissect the information into different styles of TLSOs. The conclusions from the study stated that “The anteriorly directed force from the PL pad created an undesired moment on the spine. This evidence should be considered for IS curves that are hypokyphotic or at risk of becoming hypokyphotic. For cases of scoliosis and concomitant hyperkyphosis, the forces of the PL pad would encourage a more normal kyphotic angle by straightening the spine in the sagittal plane.”
In my opinion, the PL pad should be used solely in the case of hyperkyphotic scoliosis curves, but I would like to retract this statement from the published study. The commenter makes a strong case that more research is needed before making such a conclusive statement.
Zach Harvey CPO