Traumatic brain injury (TBI) in combat sports is relatively common, and rotational acceleration (RA) is a strong biomechanical predictor of TBI. This review summarizes RA values generated from head impacts in combat sport and puts them in the context of present evidence regarding TBI thresholds. PubMed, EMBASE, Web of Science, Cochrane Library and Scopus were searched from inception to 31^st December 2021. Twenty-two studies presenting RA data from head impacts across boxing, taekwondo, judo, wrestling and MMA were included. The AXIS tool was used to assess the quality of studies. RA was greater following direct head strikes compared to being thrown or taken down. RA from throws and takedowns was mostly below reported injury thresholds. Injury thresholds must not be used in the absence of clinical assessment when TBI is suspected. Athletes displaying signs or symptoms of TBI must be removed from play and medically evaluated immediately. Methodological heterogeneity made it difficult to develop sport-specific conclusions. The role of headgear in certain striking sports remains contentious. RA can be used to suggest and assess the effect of safety changes in combat sports. Gradual loading of training activities based on RA may be considered when planning sessions. Governing bodies must continue to work to minimize RA generated from head impacts. Prospective research collecting real-time RA data is required to further understanding of TBI in combat sports.

Context: Recently, locomotor training with robotic assistance has been found effective in treating spinal cord injury (SCI). Our case report examined locomotor training using the robotic suit hybrid assistive limb (HAL) in a patient with complete C4 quadriplegia due to chronic SCI. This is the first report examining HAL in complete C4 quadriplegia. Findings: The patient was a 19-year-old man who dislocated C3/4 during judo 4 years previously. Following the injury, he underwent C3/4 posterior spinal fusion but remained paralyzed despite rehabilitation. There was muscle atrophy under C5 level and no sensation around the anus, but partial sensation of pressure remained in the limbs. The American Spinal Injury Association impairment scale was Grade A (complete motor C4 lesion). HAL training was administered in 10 sessions (twice per week). The training sessions consisted of treadmill walking with HAL. For safety, 2 physicians and 1 therapist supported the subject for balance and weight-bearing. The device's cybernic autonomous control mode provides autonomic physical support based on predefined walking patterns. We evaluated the adverse events, walking time and distance, and the difference in muscle spasticity before and after HAL-training using a modified Ashworth scale (mAs). No adverse events were observed that required discontinuation of rehabilitation. Walking distance and time increased from 25.2 meters/7.6 minutes to 148.3 meter/15 minutes. The mAs score decreased after HAL training. Conclusion: Our case report indicates that HAL training is feasible and effective for complete C4 quadriplegia in chronic SCI.

Background: The nerve autograft remains the gold standard when reconstructing peripheral nerve defects. However, although autograft repair can result in useful functional recovery, poor outcomes are common, and better treatments are needed. The purpose of this study was to evaluate the effect of purified exosome product on functional motor recovery and nerve-related gene expression in a rat sciatic nerve reverse autograft model. Methods: Ninety-six Sprague-Dawley rats were divided into three experimental groups. In each group, a unilateral 10-mm sciatic nerve defect was created. The excised nerve was reversed and used to reconstruct the defect. Group I animals received the reversed autograft alone, group II animals received the reversed autograft with fibrin glue, and group III animals received the reversed autograft with purified exosome product suspended in the fibrin glue. The animals were killed at 3 and 7 days and 12 and 16 weeks after surgery. Evaluation included compound muscle action potentials, isometric tetanic force, tibialis anterior muscle wet weight, nerve regeneration–related gene expression, and nerve histomorphometry. Results: At 16 weeks, isometric tetanic force was significantly better in group III (p = 0.03). The average axon diameter of the peroneal nerve was significantly larger in group III at both 12 and 16 weeks (p = 0.015 at 12 weeks; p < 0.01 at 16 weeks). GAP43 and S100b gene expression was significantly up-regulated by purified exosome product. Conclusions: Local administration of purified exosome product demonstrated improved nerve regeneration profiles in the reverse sciatic nerve autograft rat model. Thus, purified exosome product may have beneficial effects on nerve regeneration, gene profiles, and motor outcomes.

Context: Patients with complete quadriplegia after high cervical spinal cord injury are fully dependent with activities of daily living. Assistive technology can improve their quality of life. We examined the use of a hybrid assistive limb for single joints (HAL-SJ) in a 19-year-old man with complete C4 quadriplegia due to chronic spinal cord injury to restore function of active elbow flexion. This is the first report on the use of the HAL-SJ in a patient with spinal cord injury. Findings: The HAL-SJ intervention for each elbow was administered in 10 sessions. Clinical assessment using surface EMG was conducted to evaluate muscle activity of the trapezius, biceps brachii, infraspinatus, and triceps brachii muscle before, and during the 2nd, 3rd, 6th, and 9th interventions. Surface electromyography (EMG) before intervention showed no contraction in the upper arms, but in the bilateral trapezius. The HAL-SJ used motion intention from the right trapezius for activation. After the 6th and 7th session, respectively, biceps EMG showed that voluntary contraction and right elbow flexion could be performed by motion intention from the right biceps. After the 10th session, voluntary bicep contraction was possible. HAL-SJ treatment on the left elbow was performed using the same protocol with a similar outcome. After completing treatment on both upper extremities, both biceps contracted voluntarily, and he could operate a standard wheelchair for a short distance independently. Conclusion: HAL-SJ intervention is feasible and effective in restoring elbow flexor function in a patient with C4 chronic spinal cord injury and complete quadriplegia.

Update: This article was updated on October 19, 2022, because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 1787, in the legend for Figure 2, the sentence that had read “The vertebral collapse rate (in %) was defined as 1 − (A/P) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images.” now reads “The vertebral collapse rate (in %) was defined as (1 − [A/P]) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images.” On page 1788, in the section entitled “Data Collection,” the sentence that had read “The vertebral collapse rate (in %) was defined as 1 − (anterior vertebral wall height/posterior vertebral wall height) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images⁹.” now reads “The vertebral collapse rate (in %) was defined as (1 − [anterior vertebral wall height/posterior vertebral wall height]) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images⁹.” Finally, on page 1791, in Table IV, the footnote for the “Primary outcome” row that had read “N = 113 in the rest group and 99 in the no-rest group.” now reads “N = 116 in the rest group and 108 in the no-rest group.” Background: Although imaging findings that predict resistance to conservative treatment in patients with osteoporotic vertebral fracture (OVF) have recently been reported, no conservative treatment method has been standardized. In this study, the effects of initial bed rest on the outcomes of patients with OVF and in patients with and without poor prognostic findings on magnetic resonance imaging (MRI) were compared. Methods: This prospective cohort study at 2 facilities involved consecutive patients aged ≥65 years with OVF who began treatment within 2 weeks after their injury and were observed for 6 months. Patients at one hospital rested for 2 weeks (116 patients; mean age, 80.4 years), whereas those at the other hospital were not instructed to rest (108 patients; mean age, 81.5 years). Patients were further divided according to the presence or absence of poor prognostic MRI findings. The primary end point was the rate of transition to surgery; secondary end points included bone union rate, vertebral collapse progression, local kyphosis progression, and changes in activities of daily living (ADL). Results: Forty-five patients in the rest group (including 3 who required surgery) and 37 patients in the no-rest group (including 9 who required surgery) had poor prognostic MRI findings. Although the difference in the rate of transition to surgery between the rest and no-rest groups did not reach significance among all patients (p = 0.06), the transition rate in the rest group was significantly lower (p = 0.02) in the patients with poor prognostic MRI findings. Both the bone union rate and changes in ADL were not significantly different between the rest and no-rest groups. The mean vertebral collapse progression was 6.4% in the rest group and 20.9% in the no-rest group (p < 0.001), and the mean local kyphosis progression was 2.4° in the rest group and 8.8° in the no-rest group (p < 0.001). Conclusions: Although bed rest is not recommended for all patients, hospitalized bed rest for 2 weeks reduced the number of patients with OVF who require surgery among patients with poor prognostic MRI findings. Bed rest also reduced progression of vertebral collapse and kyphosis, regardless of the MRI findings. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.