September 27, 2015

The Flexion Synergy is Good and Bad

At first, an arm paralyzed by a stroke is limp (Brunnstrom Stage 1).  Stage 2 is exciting because stroke survivors see small limb movements.  In Stage 2 I could fling my hand onto my thigh, but my hand slid off because my arm muscles were too weak to hold it there.  Small movements turn into a synergy (Stage 3).  Synergy means muscles work together, but a stroke creates abnormal synergies that produce only one movement pattern.  This is bad because you cannot change where you place you hand.  The photo shows one version of the flexion synergy that affects the arm.  There are many versions so your movement pattern may look different.  The flexion synergy is also bad because to move one joint you have move the whole arm whether you want to or not.  This is exhausting.  When Stage 3 becomes full blown the hand is fisted and the arm is close to the body.


An electrical stimulation device called NeuroMove that has a biofeedback component and a spring-loaded hand splint called SaeboFlex helped me modify Stage 3 to make it functional.  They helped me retrain my brain to open my hand a few inches so I could receive an object from my sound hand.  Hand-to-hand transfers let me hold an object close to my body so my sound hand can manipulate the object.  Hand-to-hand transfers made me independent in 18 Activities of Daily Living (ADLs).

Brunnstrom Stage 4 brings more shoulder, elbow, and forearm motions that move the hand farther away from the body (photo on left).  My hand is still synergy bound which means I cannot open my hand unless I also move my arm.  My Stage 4 skills are: 1) keeping my hand open when I reach at waist height and
2) partially rotating my forearm to orient my hand to different positions objects require.  Bringing a partially open hand to an object is very important because the non-dominant hand assists the dominant hand thousands of times in a life time.

I was stunned to learn my hand is useful without achieving Stage 5 (relative independence from synergy).  The Neurodevelopmental Treatment Approach (NDT) says the hand needs good shoulder control.  This is true if you want to swing a hammer without hitting your thumb.  Many ADLs do not require this kind of precision.  Why defer hand use when ADLs can make do with emerging arm and hand movements?  As an OT I knew that stroke survivors learn to walk using the extension synergy in the leg, but I was taught the flexion synergy in the arm was bad.  I had to have a stroke to see the flexion synergy in the arm in a more positive light. 

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