Dynasplint

Almost a year ago, I broke the humerus in my right arm:

True Life: I did this arm wrestling with an old housemate… “Arm wrestling? Sure, I haven’t done that in forever, what’s the worse that could happen?”

While the bone was healing, my arm was in a sling for five weeks.  I learned to be pretty good at one-handed typing with my left hand, since I was submitting my master’s thesis in four weeks.  After getting my arm out of the sling, I had lost quite a bit of my range of motion.  I could not extend my arm because the bicep and connective tissue had become so taught from being held up in the sling for so long:

Shortly after getting out of the sling. (Coke museum in Atlanta with my sister).

I was distraught to see how messed up (and weak) my arm had become.  Fortunately for me, help was on the way IN THE FORM OF TECHNOLOGY.  My physical therapist hooked me up with a Dynasplint rental.  A Dynasplint is basically a medieval torture device in which you crank down on some springs with a key which then forces your arm (or leg or jaw(?) etc) to stop misbehaving, and extend like normal.

The Dynasplint representative said I should have worked up until I was able to wear it all night while sleeping but this thing HURTS LIKE HELL.  The rental was pricey but definitely worth it–I’m pretty sure that the Dynasplint did more to help me regain something close to my original range of motion than sessions with the physical therapist did.  I’ll mention again that it HURTS LIKE HELL.  I don’t think I ever made it much beyond an hour and fifteen minutes wearing the device.  The pain would just increase as time wore on while wearing it too–it was nuts.  I definitely never fell asleep wearing the Dynasplint, but the pain was worth getting my range of motion back.  And, after about five months in the gym, I was back to my pre-break weight lifting strength too.

Getting medieval on my misbehaving arm

Due to the construction of the thing, I couldn’t really tell how the springs in the design worked on your arm.  There might be powerful clock springs in the elbow joints on either side of your arm, and cranking on the key was what tightened them.

The key for tightening the springs is inserted at the “hand end” of the forearm rod

Alternatively, linear springs in the forearm rods may have connected to a feature in the elbow joint which was offset from the center of the elbow pivot point to provide the necessary torque.  I’m just not sure–too much of the hardware was hidden under the rods and joints.  The designers were smart to provide a graduated tension scale in the forearm rods on both sides of the forearm rods in order to allow the user to make sure that the torque was equal on both sides of the arm:

I highly recommend the Dynasplint for anyone fresh off of breaking a bone and is in physical therapy, trying to regain range of motion.  With pain comes gain, and I attribute getting most of my elbow extension back to the Dynasplint.