RCT on foot orthotics for low back pain

Do we really know this?

LLD is one of the very obvious potential causes of LBP that improves when addressed correctly. That is also secondary LBP, not primary. This study make no distinction as Robert pointed out and LBP is a very broad clinical brush.

I would love to hear what the MD says with regard to primary low back pain Carol.

:drinks

 

Good enough for me - thanks Craig.

 

We got a 2mm plate of polyester resin- influence on metatarsphalangeal joint bending stiffness? This will not be biomechanically inert in terms of kinetics at the foot's interface. Viz. it is not a placebo, it's a 2mm polyester resin insole. We do not know the bending stiffness of the 2mm insole used in this study, but we do know that Stefanyshyn DJ and Nigg BM (Influence of midsole bending stiffness on joint energy and jump height performance. Med Sci Sports Exerc. 2000 Feb;32(2):471-6) have previously studied the effect of flat carbon fibre plates on 1st metatarsophalangeal joint extension and it's impact on performance. I doubt that the polyester resin insoles increased the bending stiffness of the shoe soles to the same extent as the carbon fibre plates did in the Nigg study because carbon fibre is likely to have a higher bending stiffness than polyester resin of a similar thickness, however, the addition of the insoles must have altered the bending stiffness of the shoes worn by the control group in this study. Of course, Dananberg has suggested a relationship between metatarsophlangeal joint bending stiffness and lower back pain.

 

What did they manufacture the orthoses out of for the treatment group?

 

I had a spare 1/2 hour at work so I took an Adidas sl76 shoe and measured the forefoot dorisflexory bending stiffness- it took about 8.2N to displace the tip of the toe of the sole vertically upward by 2cm. I then placed a 2mm thick flat polyester resin insole into the shoe and remeasured the amount of force required to displace the same section of the shoe by 2cm. With the insole in situ it took about 13.3N. I used a fairly crude set-up, I can upload photos later if necessary. If I get time, I'll repeat in my proper materials testing machine later in the week.