Key points:
1. The donor nerve has connected to the recipient muscle and the patient should start to have flickers of movement in the recipient muscle.
2. The recipient muscle is starting to move or nerve activity is noted on EMG.
3. Often the EMG shows nerve activity/connection 1-2 months before movement occurs.
4. Rehabilitation goals during this phase are to develop the ability for the donor nerve to cause a contraction of the target muscle. This often requires high volumes of repetition to establish a new nerve connection.
Information for Patients:
The waiting is over. The donor nerve is connected to the recipient muscle.
It is vital to practice movement patterns specific to your nerve transfers. This helps establish a new brain-body connection that is required to activate nerve and cause the recipient muscle to contract. Just like in the first and second phase, but now you will start to see new movement in your operated hand/arm.
This takes a lot of practice and high volumes of repetition - 1000’s of tries to build the connection between your brain and the transferred nerves to make your muscles contract and move.
Practice the recommended movements for 20-30 mins, 2x per day (at minimum).
If you have had nerve transfers on just one arm and your other arm is more functional, feel free to visualize the movement on the surgical side while performing the same action on your more functional side. This has been shown to strengthen the connection between the brain and your body.
- spinal accessory to suprascapular transfer: squeeze your shoulder blades backward while rotation your hand outward, externally rotating the shoulder (tennis backhand motion). You can push into an arm rest if seated or into the bed if lying down to increase contraction.
- triceps to axillary transfer: straighten the elbow with the arm at your side while lying on your back on a smooth surface. Try and simultaneously bring the arm away from the body making a “snow angel” type motion. As your strength improves you can transition from lying on your back to standing with your back against a wall.
- ulnar (FCU) or median (FDS) fascicle to biceps or brachialis: If you had an FCU donor, curl the wrist in and slightly towards the inside of your elbow while you simultaneously try and bend the elbow. If you had a FDS donor, then curl the fingers in while trying to bend the elbow. This can be done with gravity eliminated (lying on side with arm on a smooth surface) and progressed towards sitting upright as strength improves
- Deltoid to Triceps: Push the upper arm backwards, activating the deltoid muscle while simultaneously attempting to extend the elbow like you are ski poling while cross country skiing. Can push the arm back into a chair or bed to increase activation.
- Brachialis to AIN nerve transfer (hand closing):
-Practice curling your biceps with your thumb up and making a fist.
-Strengthening the donor muscle (brachialis) by flexing your elbow with added resistance while trying to close your hand. This resistance can be provided by a theraband, a pulley, a light weight in a universal cuff or with a counter force provided by a friend/family member/therapist.
-Try to couple the elbow flexion with closing your fingers and hand.
Information for Clinicians:
This stage starts when an EMG has shown the donor nerve is connected to the recipient muscle. Often you will start to see flickers of movement in the recipient muscle. New “nascent'' motor units may be seen on EMG in the recipient muscles a month or so before movement occurs.
Rehabilitation goals during this phase are to retrain the brain or motor relearning and improve patients ability to activate the recipient muscle.
- Practice activating the donor nerve by coupling the muscle with the desired movement pattern. This is what the patient has been practicing and visualizing in stages 1 and 2, however now patients will start to see flickers of movement with donor nerve activation.
- Encourage the patient to perform visualization exercises for 20-30 mins, 2x per day (at minimum).
- Initially exercises are done without weight and focus on improving nerve activation.
- Build the patient's ability to hold or sustain contraction as the muscle will fatigue very quickly.
- Prescribe gravity eliminated exercises first.
- Control any edema in the arm/hand.
- Maintain passive ROM of arm/hand and keep the joints supple.
- Prevent new deformities from developing/progressing.
- Nerve transfers start working at different times. This can cause unopposed motor function - e.g. finger opening before they can close the hand - and patients can quickly develop MCP/PIP hyperextension joint deformities.
- Patients may need splints for their hand/fingers during this phase for approximately 3-6 months until their flexor muscles start activating - e.g. MCP hyperextension blocking splint.
Tips to promote donor activation:
- Surface EMG - Surface EMG can provide biofeedback to patients to help teach them how to activate the donor muscle to perform the intended movement. For example, listening to finger extension muscle activity with activating supinator teaches patients how to better activate finger extension (see Surface EMG section).
- FES - FES is a device that stimulates muscles and exercises the desired movement pattern when patients are having difficulties with activating/exercising the muscle independently.
