The effect of anti-pronation foot orthoses on hip and knee kinematics and muscle activity during a functional step-up task in healthy individuals: A laboratory study
Simon Lack Christian Barton, Peter Malliaras, Richard Twycross-Lewis, Roger Woledge, Dylan Morrissey Clinical Biomechanics; Available online 1 December 2013
The orthotics used i this study were Vasyli prefabs. Different orthotics with different design features probably would have given a different results, so no point extrapolating the results of this study to anything.
The results of the study are only applicable to foot orthoses that use the design feature of the type of foot orthoses used in that study. They can not be extrapolated to "foot orthotics" in general and to foot orthotics that use design features different to the one that was used in the study.
quote: "Different orthotics with different design features probably would have given a different results, so no point extrapolating the results of this study to anything".
Would you therefore apply this "logic" to all studies that use either a custom or a pre-fabricated foot orthotic? Also, the use of the term "probably" seems somewhat
non-scientific for you Craig?
Yes. At best custom orthoses studies are a series of n=1 case studies. You could argue the same for prefab studies too. I made this point here: http://www.ncbi.nlm.nih.gov/pubmed/22965220
Would this therefore negate the use of a meta analysis to evaluate the efficacy of the use of foot orthotics in say the treatment of plantar fasciitis or PFP?
Each trial outcome would be bound solely to the use of a particular device making extrapolation between similar studies (but with different foot orthotics) meaningless. Just a thought.
Different orthotic design features have different kinematic and kinetic effects. Foot orthoses with midfoot arch support design features will have different effects to rearfoot medial wedging design features. Doesn't matter of they are custom made or prefabricated - its the design features that they have.
Nope. The the concept of p values is based on probability theory.
Theoretically, yes. What if a study is on, for eg plantar fasciitis and used a foot orthotic design feature that jammed up the windlass mechanism and increased the load in the plantar fascia and did not work. What if another study on plantar fasciitis used a foot orthotic design feature that facilitated the windlass mechanism and lowered the load in the tissue and did work. If you were to do a meta-analysis of those two studies, what would your conclusion be if orthotics worked in plantar fasciitis?