Everyday movement and use of the arms: Relationship in children with hemiparesis differs from adults.

PURPOSE: In adults with hemiparesis amount of movement of the more-affected arm is related to its amount of use in daily life. In children, little is known about everyday arm use. This report examines the relationships between everyday movement of the more-affected arm and its (a) everyday use and (b) motor capacity in children with hemiparesis. METHODS: Participants were 28 children with a wide range of upper-extremity hemiparesis subsequent to cerebral palsy due to pre- or peri-natal stroke. Everyday movement of the more-affected arm was assessed by putting accelerometers on the children's forearms for three days. Everyday use of that arm and its motor capacity were assessed with the Pediatric Motor Activity Log-Revised and Pediatric Arm Function Test, respectively. RESULTS: Intensity of everyday movement of the more-affected arm was correlated with its motor capacity (rs ≥ 0.52, ps ≤ 0.003). However, everyday movement of that arm was not correlated with its everyday use (rs ≤ 0.30, ps ≥ $ 0.126). CONCLUSIONS: In children with upper-extremity hemiparesis who meet the study intake criteria amount of movement of the more-affected arm in daily life is not related to its amount to use, suggesting that children differ from adults in this respect.

Network of movement and proximity sensors for monitoring upper-extremity motor activity after stroke: proof of principle.

OBJECTIVE: To test the convergent validity of an objective method, Sensor-Enabled Radio-frequency Identification System for Monitoring Arm Activity (SERSMAA), that distinguishes between functional and nonfunctional activity. DESIGN: Cross-sectional study. SETTING: Laboratory. PARTICIPANTS: Participants (N=25) were ≥0.2 years poststroke (median, 9) with a wide range of severity of upper-extremity hemiparesis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: After stroke, laboratory tests of the motor capacity of the more-affected arm poorly predict spontaneous use of that arm in daily life. However, available subjective methods for measuring everyday arm use are vulnerable to self-report biases, whereas available objective methods only provide information on the amount of activity without regard to its relation with function. The SERSMAA consists of a proximity-sensor receiver on the more-affected arm and multiple units placed on objects. Functional activity is signaled when the more-affected arm is close to an object that is moved. Participants were videotaped during a laboratory simulation of an everyday activity, that is, setting a table with cups, bowls, and plates instrumented with transmitters. Observers independently coded the videos in 2-second blocks with a validated system for classifying more-affected arm activity. RESULTS: There was a strong correlation (r=.87, P<.001) between time that the more-affected arm was used for handling objects according to the SERSMAA and functional activity according to the observers. CONCLUSIONS: The convergent validity of SERSMAA for measuring more-affected arm functional activity after stroke was supported in a simulation of everyday activity.

Sensor-enabled RFID system for monitoring arm activity: reliability and validity.

After stroke, capacity to complete tasks in the treatment setting with the more-affected arm is an unreliable index of actual use of that extremity in daily life. Available objective methods for monitoring real-world arm use rely on placing movement sensors on patients. These methods provide information on amount but not type of arm activity, e.g., functional versus nonfunctional movement. This paper presents an approach that places sensors on patients and household objects, overcoming this limitation. An accelerometer and the transmitter component of a radio-frequency proximity sensor are attached to objects; the receiver component is attached to the arm of interest. The receiver triggers an on-board radio-frequency identification tag to signal proximity when that arm is within 23 cm of an instrumented object. In benchmark testing, this system detected perfectly which arm was used to move the target object on 200 trials. In a laboratory study with 35 undergraduates, increasing the amount of time target objects were moved with the arm of interest resulted in a corresponding increase in system output . Moreover, measurement error was low ( ≤ 2.5%). The results support this system's reliability and validity in individuals with unimpaired movement; testing is now warranted in stroke patients.

Sensor-enabled RFID system for monitoring arm activity in daily life.

After stroke, capacity to carry out tasks in the treatment setting with the more-affected arm is a poor index of actual use of that extremity in daily life. However, objective methods currently available for monitoring real-world upper-extremity use only provide information on amount of activity. These methods, which rely on movement sensors worn by patients, do not provide information about type of activity (e.g., functional vs. nonfunctional movement). The benchmark testing reported here evaluated an approach that involves placing sensors on patients and objects. An accelerometer and the transmitter component of a prototype radio frequency proximity sensor were attached to household objects. The receiver component was placed on the experimenter's right arm. This device triggered an on-board radio frequency identification tag to signal proximity when that arm was within 23 cm of the objects. The system detected > 99% of 6 cm or greater movements of objects. When handling of objects by the right or left arm was determined randomly, 100% of right arm trials were detected. No signals were recorded when objects were at rest or moved by the left arm. Testing of this approach, which monitors manipulation of objects (i.e., functional movement), is now warranted in stroke patients.