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Characterizing Submental Neuromuscular Activity of Swallowing Rehabilitation: An Electromyographic Evaluation of Rehabilitative Maneuvers in Healthy Adults.

PURPOSE: The effortful swallow (ES), the Mendelsohn maneuver (MM), and isometric tongue presses (TPs) are widely used swallowing maneuvers/exercises to improve elements of swallowing, such as muscle strength and biomechanics. However, the underlying neuromuscular mechanisms of these exercises remain unclear, potentially limiting our ability to specify treatment targets and improve treatment efficacy. This study aimed to compare submental neuromuscular activation patterns during the ES, MM, TPs, and typical swallows in healthy young and older adults. METHOD: As part of a larger randomized crossover validation study, 60 healthy adults (30 young and 30 older) completed typical swallows and three maneuvers using a wearable submental surface electromyographic (sEMG) system (i-Phagia). Outcome variables included (a) normalized mean sEMG amplitude and (b) time to peak sEMG amplitude. Linear mixed models were used to examine effects of task, age, and sex on both outcomes. RESULTS: Normalized mean amplitude was significantly different across tasks. Post hoc pairwise comparisons confirmed that all three maneuvers produced higher normalized mean sEMG amplitude than typical swallows, with the ES eliciting the highest amplitude across age groups. Time to peak amplitude differed significantly across tasks, with typical swallows requiring the shortest time to reach peak amplitude, followed by the ES, MM, and TP. CONCLUSIONS: The ES required the highest neuromuscular effort with the shortest time to reach peak amplitude, suggesting its potential for targeting submental muscle power. Typical swallows required the least neuromuscular effort with the shortest time to reach peak amplitude, suggesting their potential for training submental muscle speed. The MM and TP may also improve submental muscle strength; however, given their temporal requirements (longer durations), they may be more beneficial for targeting coordination and endurance, though more research in this area is warranted. These findings underscore the importance of task-specific neuromuscular profiling to inform mechanism-based swallowing rehabilitation. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.32948549.

Humans

Postoperative Curvature Loss in Three-Level Anterior Cervical Discectomy and Fusion With Zero-Profile Device.

PURPOSE: Cervical curvature loss is a frequent complication following 3-level anterior cervical discectomy and fusion (ACDF) using a Zero-Profile device. Consequently, the capacity of this device to maintain cervical sagittal alignment in 3-level ACDF remains highly controversial. This study aimed to identify potential predictors for postoperative curvature loss (PCL) and evaluate its impact on clinical outcomes. METHODS: A total of 113 patients who underwent ACDF for 3-level cervical degenerative disc disease (CDDD) between January 2021 and December 2023 were retrospectively reviewed. Demographic data, radiological parameters, and clinical outcomes were analyzed. Radiographic measures included cervical curvature, T1 slope, C2-7 sagittal vertical axis, and titanium plate and endplate (TPE) distance. Clinical outcomes were assessed using the Visual Analog Scale (VAS), Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) scores. Statistical analyses were performed using paired and independent t-tests, as well as Pearson correlation coefficients. RESULTS: The average curvature loss was 6.82&#xb0; from 1&#x2009;week postoperatively to the final follow-up (p&#x2009;<&#x2009;0.001). However, the final curvature (11.65&#xb0;) was maintained, representing a 4.33&#xb0; improvement compared to preoperative values. Significant correlations were observed between PCL and preoperative curvature (r&#x2009;=&#x2009;-0.368, p&#x2009;=&#x2009;0.013), preoperative T1 slope (r&#x2009;=&#x2009;-0.546, p&#x2009;<&#x2009;0.001), &#x2206;T1 slope (r&#x2009;=&#x2009;0.443, p&#x2009;=&#x2009;0.002), and &#x2206;TPE distance (r&#x2009;=&#x2009;0.417, p&#x2009;=&#x2009;0.004). PCL did not correlate with Japanese Orthopaedic Association (JOA) scores or arm VAS scores at the final follow-up. Nevertheless, patients with a PCL&#x2009;&#x2265;&#x2009;6&#xb0; exhibited significantly higher neck VAS (p&#x2009;=&#x2009;0.028) and NDI scores (p&#x2009;=&#x2009;0.041). CONCLUSION: Although contiguous 3-level ACDF with a Zero-Profile device may result in PCL, it preserves an improved cervical lordosis compared to the preoperative baseline. Low preoperative curvature and a low preoperative T1 slope are potentially predictive factors for PCL. Postoperative changes in TPE distance and T1 slope are significantly associated with PCL, suggesting a potential biomechanical link that requires direct validation. Furthermore, PCL may lead to higher neck VAS and NDI scores. Consequently, the Zero-Profile device may require careful consideration in 3-level CDDD patients presenting with low preoperative curvature and a low T1 slope. Importantly, the 6&#xb0; PCL threshold identified is preliminary and requires prospective validation before clinical application.

Humans