Quantifying real‐world upper limb activity via patient‐initiated spontaneous movement in neonatal brachial plexus palsy

Abstract

Background: Neonatal brachial plexus palsy (NBPP) results in muscle weakness and impaired somatosensory function of the arm. Current functional assessment is primarily based on clinician-elicited measurements including muscle strength and range of motion. To what extent these measures are representative of real-world arm movement is unclear. Objective: To determine the feasibility of using body-worn accelerometers to remotely assess arm movements in children with NBPP. Design: Prospective criterion validity study of accelerometry versus clinician assessment. Setting: Academic medical center. Participants: Nine adolescents with NBPP and nine age-and gender-matched control adolescents participated in the study. All were enrolled in school and participated in community activities.Interventions: Not applicable. Methods: Standard clinician-elicited measurements were collected. For assessing spontaneous arm movements, participants wore activity monitors during all waking hours for 7 days. Results were expressed as ratios of affected to unaffected arm motion for duration and magnitude and correlated with traditional clinic-based assessments. Spearman correlations were used to determine relationships between accelerometry results and traditional assessments. A p value <.05 was considered statistically significant. Main Outcome Measurements: Accelerometry measurements of arm motion and traditional clinical assessments. Results: Compared to control ratios, duration of arm movement and magnitude ratios were reduced in the NBPP group, particularly for arm magnitude due to reduced affected arm movement and an increase in unaffected arm movement. Ratios were highly correlated with shoulder function and, to a lesser extent, with elbow function. Conclusion: Real-world arm use is an appropriate outcome measure that reflects functional recovery. This study demonstrates the feasibility of wearable technology to quantify duration and intensity of spontaneous arm movement in children with NBPP. Accelerometry also allows for the association between traditional clinician-elicited assessment measures and spontaneous arm movements, demonstrating the importance of the shoulder as a focus of treatment in NBPP.

Early referral to multidisciplinary specialty centers to optimize outcomes in children with neonatal brachial plexus palsy

“…However, a recent study of adults with brachial plexus injury showed a direct correlation between shoulder AROM and real-world use of the arm as measured using wearable technology, emphasizing the importance of adequate shoulder movement to spontaneous, patient-initiated use of the arm in everyday life. 18,19 These studies underscore the importance of our findings that children evaluated at a specialty center within 30 days have significantly better long-term AROM in shoulder abduction and forward flexion. While not statistically significant at the latest time point, shoulder external rotation AROM for the early group was consistently better than for the later group.…”

“…While useful in assessing longitudinal improvements in a specific aspect of upper-extremity function, AROM does not necessarily reflect real-life use of the arm to participate in activities of daily living. 34 We recently demonstrated the feasibility of wearable motion sensors to better assess true, real-world arm function in adults with brachial plexus injury; 18,19 the use of accelerometry data to determine patient outcomes in this population is another important direction for future work. 19 Additionally, we did not investigate differences in passive range of motion between cohorts.…”

Recovery of Shoulder, Elbow, and Forearm Movement After Nerve Reconstruction for Neonatal Brachial Plexus Palsy

“…The use of wearable motion detectors to assess arm function outside of the clinic represents an important future direction for this work. [25][26][27]…”

Quantifying Patient-Initiated Upper Extremity Movement After Surgical Reconstruction for Adult Pan-Brachial Plexus Injury

“…We derived 2 outcome measures from the accelerometry data: vector time (VT), which describes the amount of time each day (in hours) during which the accelerometer measured movement, and vector magnitude (VM), which describes acceleration in all 3 axes measured as a single VM for each second of recorded data. [17][18][19] To demonstrate the proportion of time the affected arm was in motion relative to the unaffected arm, we divided the VT of the affected arm by the VT of the unaffected arm. We performed the same calculation for VM to understand the magnitude or intensity, with which the affected arm moved compared with the unaffected arm.…”

“…These technologies have already been used to measure spontaneous movement in patients with amyotrophic lateral sclerosis, stroke, Parkinson disease, and reverse shoulder arthroplasty. [12][13][14][15][16] We have recently demonstrated the feasibility of using wearable motion detectors to measure spontaneous, real-world upper extremity activity in children with conservative and operatively managed neonatal brachial plexus palsy 17,18 and for adults with operatively managed upper BPI. 19 We expand on these studies by demonstrating the use of wearable accelerometers to quantify patient-initiated arm movement in adult pBPI after surgical reconstruction.…”