The Lunge test is a weightbearing measurement of ankle joint dorsiflexion. I am a big fan of it and there is some research on it. I spend a lot of time on it during the Clinical Biomechanics Boot Camp where there is a whole lesson on the lunge test. I much prefer the weightbearing lunge test over the non-weightbearing measurements. I also previously wrote that I think the lunge test should be done in footwear as this is more representative of how the foot functions.
When I have a patient try Foot Orthotics, I always do the lunge test in their shoes with the orthotics under the foot to see if they can get the 35-45 degrees at the tibia that we normally expect from the lunge test. If they can not, I then add a heel raise under the rear of the foot orthotic, usually only 3-4mm is all that is needed to get what could be considered that normal range of motion of the lunge test.
This is something that I learnt doing the practical sessions of the Clinical Biomechanics Boot Camps: it was surprising how many had a limited range of motion in the lunge test when doing it barefoot and how many had a normal range of motion when they had their shoes on. The typical shoe has a heel raise of around 10mm which we never used to take into account in the past when we did determine the ankle joint range of motion, by whatever method was used to measure it. I suggest you try it and get a feel for it. Do the lunge test barefoot. Do it again with the shoes on. Do it again with the foot orthotics in the shoe. Do it again with a 2-3mm heel raise under the rear of the orthotic. Get a feel for it. You will see what I mean.
In the past, several clinicians whose opinions I generally respect would say things like, paraphrased: “if your foot orthotics are not working like you would like them to, then add a heel raise“. What I started seeing with this lunge test may be a better way of doing this than just waiting to see if they are not working. It is a shame that this is such an under-researched area and the level of evidence is non-existent and its just based on biological plausibility and is somewhat theoretically coherent. Good research on this could or would have immediate clinical applications. HINT: any researchers want to look further into this?