Use of Wearable Sensors to Measure Improvements in Real World Upper Extremity Activity After Brachial Plexus Reconstruction

PURPOSE: Current functional assessments after brachial plexus (BP) reconstruction, including surgeon-graded active range of motion and strength scores, and patient-reported outcomes (PROs), have limitations. This study evaluated the feasibility of wearable sensors to quantify recovery and functional outcomes following BP reconstruction. We hypothesized that sensor-derived measures of daily upper-extremity use would correlate with PROs and that real-world upper-extremity use would improve. METHODS: Traumatic BP injury patients wore bilateral wrist accelerometers for 7-day periods at 3- to 6-month intervals. Data were grouped relative to timing of reconstruction. Duration and magnitude of upper-extremity activity were expressed as ratios of injured to uninjured limb (use and magnitude ratios). Disabilities of the Arm, Shoulder, and Hand; Impact of BP Injury; 36-Item Short Form Health Survey; and Patient-Reported Outcomes Measurement Information System-Upper Extremity scores were collected. Correlations assessed relationships between accelerometry data and PROs. Linear mixed models characterized changes in these relationships over time and the effect of time from surgery on accelerometry data. RESULTS: Twenty-seven participants were enrolled (82% male, 78% White). Mean age at injury and surgery were 41.7 ± 14.0 years and 42.5 ± 14.3 years, respectively. The use ratio correlated significantly with Disabilities of the Arm, Shoulder, and Hand (r = -0.45, P < .05), Impact Disability (r = -0.56, P < .05), 36-Item Short Form Health Survey Physical Function (r = 0.26, P < .05), and Patient-Reported Outcomes Measurement Information System-Upper Extremity (r = 0.38, P < .05) scores. The magnitude ratio significantly correlated with Disabilities of the Arm, Shoulder, and Hand (r = -0.44, P < .05), Impact Disability (r = -0.50, P < .05), and Patient-Reported Outcomes Measurement Information System-Upper Extremity (r = 0.47, P < .05) scores. Linear mixed models supported these associations but showed no effect of time from surgery on use or magnitude ratios. CONCLUSIONS: Wearable sensor-derived use and magnitude ratios demonstrate convergent validity with PROs following BP reconstruction. CLINICAL RELEVANCE: Wearable sensors may offer a more direct, objective assessment of functional recovery to support postoperative assessment, prognostication, treatment planning, and counseling beyond traditional clinical measures.