The NIH Toolbox is an incredible resource for physical and occupational therapists. NIH has developed population based norms for the 2 Minute Walk Test, grip, and 4 Meter Walk Test. PROMIS and NeuroQOL are a part of this initiative. PROMIS and NeuroQOL have great questionnaires that can be used to help you gather information on the youth you work with. I especially love the pain and fatigue questionnaires.
The intent, though, of NIH Toolbox is to share all of these tools via an iPad app that costs $500. The manuals for each tool are available freely, online, and with it, are the norms.
As I share Fit4Work, I have been promoting use of these types of norms, but as I update my book I ran in to a huge stumbling block: Derivatives of the norms have been published as norms for 2 Minute Walk Test and grip for children and adults. To complicate matters, the NIH norms include samples for English and Spanish speaking people. The numbers are definitely different for these groups, and the NIH averages are different than the 2 studies I previously cited. So the question is, which norms should we be using?
1.It is best practice when you want to compare a person to a normative population, the person needs to belong to that population for age, gender, socioeconomic and other factors. We know that 6 Minute Walk Test varies widely based on the population.
2.Our tools are only so sensitive...on the 2 Minute Walk Test I am looking at total feet walked and not including fractions of a foot. My grip dynamometer does not report fractions.
3. When using a dynamometer these norms are for a Jamar Grip dynamometer, not other kinds. When I questioned the vendor of a dynamometer with a digital output, they claimed the dynamometer reported within 2 pounds...when the expectation is under 20 pounds, 2 pounds is more than 10% which is too high for me.
4. In the dynamometer article I noticed that they removed some of the data points for those who were more than 2.5 standard deviations, and where other data was missing. Frankly, if I am comparing to a normative sample I think those should be included. Additionally, the demographic of youth I work with include many from Asia and the Middle East.
So what do I suggest? Use your clinical reasoning skills:
Grip dynamometry can be used to rule in a cause of impairment, but just because you don't have a normal score does not mean you can't grip, it means that you could not do that test. We have youth who just can't follow test directions but have a subjectively strong grip when asked to do other things.
For walking tests, these are great outcomes measures so you can demonstrate improvement.
If I had a Spanish speaking student I would consider the Spanish norms, but I would also have to administer in Spanish which I cannot.
So I think that I am going to use my clinical judgment to cautiously interpret my results using the NIH norms. These are population based, and the population is matched for age, sex, and socioeconomic variables. I am going to include all 3 in the new book so that you can use your clinical judgment as well :)