A NEW METHOD TO DETERMINE MUSCLE AND MOVEMENT ACTION DURING DAILY ACTIVITIES IN PATIENTS WITH NEURALGIC AMYOTROPHY

Background: Neuralgic Amyotrophy (NA) often results in pain and paresis of shoulder muscles, causing compensatory movement strategies. Performance of daily activities, especially those including reaching and repetitive actions... [ view full abstract ]

Background:
Neuralgic Amyotrophy (NA) often results in pain and paresis of shoulder muscles, causing compensatory movement strategies. Performance of daily activities, especially those including reaching and repetitive actions may cause problems. To gain more insight in muscle activation and kinematics of the affected upper extremity, we used accelerometry in combination with electromyography to provide feedback for patients and therapists.
Method:
In a pilot study, 10 NA patients and 10 controls performed a set of daily activities during a 30-minute period, alternating light activities (drinking coffee or reading a newspaper) with more demanding activities (placing books on a shelf or reaching for a jacket). The order of the activities was standardized, but persons were free to perform the activities in their own manner. Muscle activity of the serratus anterior, lateral deltoid and trapezius decendens muscles was recorded using surface EMG. Upper arm movements were recorded using a 3D accelerometer placed on the upper arm. The percentage of time EMG activity was above a set threshold and the sum of accelerations in three directions were calculated by adding the signal magnitude area (SMA) of the accelerations.
Results:
Timing of substantial activity in the EMG and accelerometer signals corresponded very well with the timing of high demanding upper arm activities (e.g. placing books on a shelf and reaching high for a jacket).
Conclusion and application to Practice:
This method seems promising to provide non-invasive feedback to patients and therapists. Further research and development of a practical measurement tool for therapeutic use are recommended.