You Might Be Using Hand-Held Dynamometry Incorrectly
by Claire Minshull
Have you got a dynamometer? Do you know how to use it? Do you know its sampling frequency and limitations? Perhaps you’re thinking about purchasing a dynamometer? What’s your preference? What are you basing your decision on?
I have no idea how many hand-held (and other) dynamometers there are on the market now…Scores, probably hundreds. On the one hand (ahem), this is great; measuring muscle force production objectively only used to be achievable by researchers in laboratories or by clinicians in very well-off facilities who could afford a swanky isokinetic dynamometer (which isn’t the ‘gold standard’ by the way).
On the other hand, increased accessibility and commercialisation has meant a lack of attention to detail to really important things that govern how useful, if at all, the data is that you’re collecting. Effectively, we’re all just grabbing these tools off the shelf without proper training on how to use them, and understanding if they’re any good.
Let’s cover some of these critical issues and equip you with some of the knowledge needed to use dynamometry to collect useful data - meaning that you better understand how to create meaningful assessments and understand what the ‘number’ that you see on your device represents.
Just a note here: a lot of what I’m covering is underpinned by statistics and is well known and practiced within the scientific community. However, mindful that a stats lecture will likely be as popular as a hedgehog at a balloon party, I’m going to focus on the practical strategies and skirt over a lot of the stats. I’ll refer out to where you can read more if you’re interested.
What’s in a number?
Just because you have a ‘number’ it doesn’t mean that it’s accurate, reliable or reproducible. Worse, it can guide you into poor decision-making with patients and clients.
Most of you reading this will be testing individuals and looking for changes or differences in intra-individual performance; that is to say, assessing change over time during a rehab programme, or evaluating between-limb differences - in a single person.