For any of you that have read my blogs on twitter you are probably aware of the ongoing debates regarding functional and static assessment of the human body.
So, do we need to assess functionally? YES
Do we need to assess using our undergraduate method of active, passive and resisted range of movement (RoM)? Sometimes
Now, I’m not saying you should not assess patients using these basic tests. What I am saying is that they provide little information as to how much movement and strength you have in a particular joint, and it provides no information about how well you can control that motion.
Lets take the ankle (talocrural joint) as an example. As an undergraduate I was taught to look at A, P & RRoM on the plinth, but what does this show me? Is Dorsiflexion limited in an active and passive sense when supine compared to upright. We would look at 15-20’ A+PRoM DF in supine, but how much DF range do you get in a squat? I would suggest much more if we look at getting the knee 10-12cm over the toe as gold standard. Some of this range will obviously come from the mid-tarsal joints unlocking, but you can adjust the test to supinate or inverted the foot therefore isolating the TC joint, and you will still get more range than being supine. In an upright position the body tells me how it deals with gravity and mass which is a much stronger indicator of what the ankle can do when moving. So in this example is there any point in routinely assessing RoM in non-weightbearing? I would say, NO. There are obvious circumstances when this approach is required, neurological assessment etc, but in my opinion if someone can squat and single leg squat that shows me much more about the ankle and negates the use of basic testing.
In general resisted RoM in supine provides little information unless you are suspecting a muscular/tendon tear or ligament sprain. We are isolating muscles and saying they are weak or strong depending on how hard they push back. For most patients these are movements that they have never done before and will not do again outside and rehab or gym setting, so it’s not surprising that exercises/tests such as ‘clams’ are found to be difficult by general public. When was the last time you forcefully externally rotated the hip with the foot off the ground?? (clam)
When we are upright the body does not move with individual muscles, we move and the muscles respond by eccentrically lengthening then concentrically shortening. This happens for many reasons such as energy expenditure and proprioceptive input. The lengthening utilises elastic energy and provides information on change of length, rate of change, compression, position, load etc. Lying down on a plinth provides me with very little of this info, so why do it (with everyone)?
One argument is that it’s quick, easy and gives baseline measurements. But if these measurements do not reflect the action/movement that is the problem is there any point? Would we not get a more accurate picture if we looked at the problem movement and adjusted it to make them successful?
An example of this may be a client with medial knee pain and squatting on one leg is painful with an excessive valgus motion. If the foot is positioned in internal rotation this may limit their knee valgus and pain, if I rotate their trunk to the same side that may help by increasing the eccentric load to the gluteals in the transverse plane. These are just 2 simple ways of assessing someone’s motion and stability in a functional position. In my opinion this provides much more information than testing in a supine position when gravity, ground reaction force, mass and momentum are taken out of the equation.
I am lucky enough to work with a number of golf professionals and use the same approach to assess their movements in the golf swing. A common problem is decreased ability to load the back hip in all 3 planes when the motion is driven by the arms/trunk. What test can I use on a plinth that shows me that? Many times the hip motion is good when isolated but not when movement is coupled with the trunk. This can be used from a performance perspective but also for a treatment strategy by working on the cause of the symptoms rather than just treating the painful bit.
I am not telling anyone not to do these tests, more to think about why you are doing them?
References
-Gray Institute FVDS – Proprioceptors
-GIFT. www.grayinstitute.com
-Nike Golf 360 Performance System
Mark Leyland MCSP FAFS, www.momentum-physio.co.uk, @ Locker 27, Brooklands, Weybridge, Surrey, KT13 0YF
