Forget individual studies… they don’t count for much. Rather, let’s look at the meta-analyses (or “metas”). Metas are studies of all the studies available and will quickly tell you if something works. Or at least its the best tool we have to come as close as possible to “the truth.”
The granddaddy of all metas, the Cochrane review, has looked at splinting after stroke. The review states,
“Nine studies with a total of 1391 participants investigated the effects of splinting. The mean effect of splinting on joint mobility was 0°”
After stroke there are a number of reasons that you’re supposed to splint the wrist/hand/fingers. Here is the logic:
The survivor tends to posture with the wrist and fingers flexed (bent at the wrist and the fingers in a fist) Why do survivor’s posture like that? It has to do with the brain injury. Because the brain is no longer in full control, the stronger of the two muscle groups takes over. Imagine you have a ping pong paddle in your hand… what movement do you think is stronger, the wrist extended (like the follow through in a ping pong backhand), or the wrist forward (like the follow through in a ping pong forehand)? It’s actually the forehand/ flexion posture. OK, that’s why the wrist flexes (down, towards the forearm). What about the fingers? Same thing… the moment of the fingers to close the fingers (fist) is stronger than the movement to open the hand.
But why does this natural posture in survivors suggest to therapists that the hand and wrist be splinted? In some ways, it has to do with the same philosophy that scientific medicine has about treating everything. If she has a fever, try to cool the her down. If she can’t sleep, give her sleeping meds. If she’s nauseous, give her a pill to reduce the nausea. Of course, there is the opposite view. For instance we know that the immune system works better when the body is feverish, so maybe we should let the fever run its course. If someone can’t sleep, maybe there is a reason and the person should exercise. If there is nausea, maybe what the body is trying to rid itself of…should.
Let’s get back to splinting of the wrist/hand… What does the joint want to do? Flex. So the scientific perspective would be: do the opposite-extend. What keeps joints in an extended position? Splints. So when therapists splint, they’re taking the scientific medical perspective. But as shown by the Cochrane meta, above, the science disagrees.
One last thing; I’m sure I will hear it from the pro-splinting lobby. Please save your time if you have anecdotal “splinting worked great for me” “evidence.” Unless you are willing to collect data using high reliability/validity outcome measures and have that data accepted as a result of the peer reviewed process, it is not evidence. On the other hand, you may just be an outlier and splinting did work on you. I’d suggest, however, if you do think it worked on you, you establish that it did in fact, work. What and how did you measure? Was your measurement accurate? Was your test valid and reliable? These are the things we sweat in research. In fact, I’d suggest that if you are measuring the two things splints purport to effect, range of motion and spasticity (i.e. goniometery and the modified Ashworth), that you have a partner given that both of these tests have to be done by someone other than the tested.