Search Results (3)

Background and Objectives: The hybrid assistive limb (HAL) is a wearable robotic device used for rehabilitation that assists the voluntary movements of the user by detecting muscle action potentials and driving actuators positioned next to the hip and knee joints. Although upper-limb HAL training has been studied for brachial plexus injury (BPI), its electrophysiological influence remains unclear. The purpose of this study was to assess the electrophysiological influences of upper-limb HAL-assisted biofeedback (BF) training during elbow flexion rehabilitation in patients with BPI. Methods: Five patients with BPI (average age, 37.2 years) were enrolled after undergoing elbow flexor reconstruction through intercostal nerve-to-musculocutaneous nerve transfer. All participants received outpatient elbow flexion training with the upper-limb HAL at frequencies ranging from once weekly to once monthly. All patients started upper-limb HAL training when re-innervation was observed, and a biceps brachii muscle strength of grade 1 was achieved. Muscle activity was measured using surface electromyography in five patients during upper-limb HAL training, when the biceps brachii muscle strength was graded as Medical Research Council grades 1 and 2, to compare activity with and without HAL. Results: In five patients, electromyographic activity of the biceps brachii during elbow flexion reached 74.9 ± 22.7% of maximal contraction while using the HAL device, compared with 60.3 ± 16.7% without HAL assistance, indicating significantly greater muscle activation during HAL-assisted movement. Conclusions: Robotic BF training for elbow flexion with the upper-limb HAL may serve as a high-quality electromyographic rehabilitation approach for patients recovering from BPI. Full article

Brachial plexus injuries are challenging conditions. Over the past decades, nerve transfer surgery has progressively evolved from proximal nerve reconstruction toward selective distal neurotization strategies, considerably expanding the possibilities for functional restoration. As the number of described donor–recipient combinations has increased, the literature has become increasingly fragmented, often focusing on isolated techniques or specific functional targets. The aim of the present study was to provide a comprehensive state-of-the-art overview of currently available motor nerve transfer strategies for upper-limb reinnervation in BPI. A literature review was conducted according to PRISMA guidelines using PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science databases. Studies concerning motor nerve transfers for upper-limb reconstruction were systematically reviewed and categorized according to recipient nerve and functional target, including shoulder function, scapular stabilization, elbow flexion and extension, wrist and finger extension, wrist and finger flexion, intrinsic hand function, and extraplexal donor nerve reconstruction. A total of 250 studies met the inclusion criteria. Both intraplexal and extraplexal donor strategies were identified for most reconstructive targets. Intraplexal distal nerve transfers currently represent the preferred approach whenever feasible because of shorter reinnervation distances and more predictable outcomes. Extraplexal donors, including the spinal accessory, intercostal, contralateral C7, and phrenic nerves, remain essential in complete BPIs and root avulsion injuries. Despite substantial advances, restoration of intrinsic hand function and reliable distal reinnervation remain major reconstructive challenges. Motor nerve transfers represent an increasingly versatile and function-oriented reconstructive strategy that should be tailored to the individual injury pattern, available donor nerves, and functional priorities. Full article

Background: To restore elbow flexor muscle function in case of traumatic brachial plexus avulsion, the phrenic nerve transfer to the musculocutaneous nerve has become part of clinical practice. The nerve transfer can be done by means of video-assisted thoracic surgery without nerve graft or via supraclavicular approach in combination with an autograft. This study focuses on a detailed microscopic and macroscopic examination of the phrenic nerve. It will allow a better interpretation of existing clinical results and, thus, serve as a basis for future clinical studies. Material and Methods: An anatomical study was conducted on 28 body donors of Caucasian origin (female n = 14, male n = 14). A sliding caliper and measuring tape were used to measure the diameter and length of the nerves. Sudan black staining was performed on 15 µm thick cryostat sections mounted on glass slides and the number of axons was determined by the ImageJ counting tool. In 23 individuals, the phrenic nerve could be examined on both sides. In 5 individuals, however, only one side was examined. Thus, a total of 51 nerves were examined. Results: The mean length of the left phrenic nerves (33 cm (29–38 cm)) was significantly longer compared to the mean length of the right phrenic nerves (30 cm (24–33 cm)) (p < 0.001). Accessory phrenic nerves were present in 9 of 51 (18%) phrenic nerves. The mean number of phrenic nerves axons at the level of the first intercostal space in body donors with a right accessory phrenic nerve was significantly greater compared to the mean number of phrenic nerves axons at the same level in body donors without a right accessory phrenic nerve (3145 (range, 2688–3877) vs. 2278 (range, 1558–3276)), p = 0.034. A negative correlation was registered between age and the nerve number of axons in left (0.742, p < 0.001) and right (−0.273, p = 0.197) phrenic nerves. The mean distance from the upper edge of the ventral ramus of the fourth cervical spinal nerve to the point of entrance of the musculocutaneous nerve between the two parts of the coracobrachialis muscle was 19 cm (range, 15–24 cm) for the right and 20 cm (range, 15–25 cm) for the left arm. Conclusions: If an accessory phrenic nerve is available, it presumably should be spared. Thus, in that case, a supraclavicular approach in combination with a nerve graft would probably be of advantage. Full article