Risk of Axillary Nerve Injury in Standard Anterolateral Approach of Shoulder: Cadaveric StudyRisk of Axillary Nerve Injury in Standard Anterolateral Approach of Shoulder: Cadaveric Study

Introduction: The anterolateral acromion approach of the shoulder is popular for minimally invasive plate osteosynthesis (MIPO) technique. However, there are literatures describing the specific risks of injury of the axillary nerve using this approach. Nevertheless, most of the studies were done with Caucasian cadavers. So, the purpose of this study was to evaluate the risk of iatrogenic axillary nerve injury from using the anterolateral shoulder approach and further investigate the location of the axillary nerve, associated with its location and arm length in the Asian population that have shorter arm length compared to the Caucasian population. Materials and Methods: Seventy-nine shoulders in fourty-two embalmed cadavers were evaluated. The bony landmarks were drawn, and a vertical straight incision was made 5cm from tip of the acromion (anterolateral approach), to the bone. The iatrogenic nerve injury status and the distance between the anterolateral edge of the acromion to the axillary nerve was measured and recorded. Results: In ten of the seventy-nine shoulders, the axillary nerve were iatrogenically injured. The average anterior distance was 6.4cm and the average arm length was 30.2cm. The anterior distance and arm length ratio was 0.2. Conclusion: Our results demonstrated that the recommended safe zone at 5cm from tip of acromion was not suitable with Asian population due to shorter arm length, compared to Caucasian population. The location of axillary nerve could be predicted by 20% of the total arm-length

SIS-SEIQR adaptive network model for pandemic influenza

This paper aims to present an SIS-SEIQR network model for pandemic influenza. We propose a network algorithm to generate an adaptive social network with dynamic hub nodes to capture the disease transmission in a human community. Effects of visiting probability on the spread of the disease are investigated. The results indicate that high visiting probability increases the transmission rate of the disease

Vibration-Induced Alteration in Trunk Extensor Muscle Proprioception as a Model for Impaired Trunk Control in Low Back Pain

This study examined the impact of personalizing muscle vibration parameters on trunk control. We assessed how altered trunk extensor muscle (TEM) proprioception affects seated trunk control in healthy controls (HCs). To explore the link between altered TEM proprioception and impaired trunk control in chronic low back pain (cLBP), we performed equivalence testing between HCs undergoing TEM vibration and cLBP without vibration. Twenty HCs performed active joint reposition error (AJRE) testing to determine personalized vibration parameters. Each participant maintained balance on an unstable chair with eyes open and closed, with and without TEM vibration. We compared trunk control between HCs and twenty age- and sex-matched cLBP participants, using mean velocity and 95% confidence ellipse area of center-of-pressure changes to quantify trunk postural control. Equivalence was examined by comparing mean difference scores to minimal detectable change values and calculating between-group effect sizes. Personalized vibration parameters led to larger lumbopelvic repositioning errors (d = 0.89) than any single vibration frequency (d = 0.31–0.36). In healthy adults with no back pain, vision had large effects on postural control (ηp2 = 0.604–0.842), but TEM vibration had no significant effects (p > 0.105) or interactions with vision (p > 0.423). Between-group effect sizes (d = 0.32–0.51) exceeded our threshold for performance equivalence (d < 0.2). Muscle vibration altered position sense during AJRE testing, and personalizing parameters amplified this effect. However, TEM vibration had minimal impact on seated trunk postural control in adults with no back pain and did not lead to performance degradation comparable to that in cLBP

Comparisons of Gait Variability and Symmetry in Healthy Runners, Runners with a History of Lower Limb Injuries, and Runners with a Current Lower Limb Injury

Background: Running is a cyclic movement and requires a bilateral symmetry between the lower limbs to reduce injury risk, and the assessment of side-to-side differences is often performed to detect functional deficits. Objectives: The purpose was to study side-to-side differences using clinical and running performance assessments in healthy runners (HR), runners with a history of lower limb injuries (RHI), and runners with a current lower limb injury. Methods: Forty-three runners were recruited with 14 participants being allocated to the HR group, 13 to the RHI group, and 16 to the RLI group. Peak vertical ground reaction force (GRF), midfoot pressure, foot rotation, and gait variability were recorded using a Zebris FDM-T treadmill analysis system, and participants were also assessed using the navicular drop test. Dependent t-tests were used to determine if any differences existed between the lower limbs within each group. One-way ANOVAs were then used to investigate the side-to-side differences between the three groups. Results: Significant differences were seen in navicular drop height between lower limbs within both the HR (p=0.02) and RHI (p=0.009) groups, and side-to-side differences in foot rotation were greatest in the RLI group (~34%) compared to both the RHI (~30.5%) and HR (~24%) groups. The lateral variability of the centre of pressure was greatest in the RLI group (37.1mm) compared to the RHI (28.9mm) and HR (22.2mm) groups. Conclusion: Centre of pressure variability may help identify runners at a greater risk of lower limb injury. Side-to-side differences should be expected to progressively decrease from the injured stage, through the recovery and return to sport phases. Target goals of less than 34% side-to-side difference for foot rotation and 37.1mm for lateral centre of pressure variability may be used to help the decision making process when considering a return to running practice

Kinematic characterization of clinically observed aberrant movement patterns in patients with non-specific low back pain: a cross-sectional study

Abstract Background Clinical observation of aberrant movement patterns during active forward bending is one criterion used to identify patients with non-specific low back pain suspected to have movement coordination impairment. The purpose of this study was to describe and quantify kinematic patterns of the pelvis and trunk using a dynamics systems approach, and determine agreement between clinical observation and kinematic classification. Method Ninety-eight subjects performed repeated forward bending with clinical observation and kinematic data simultaneously collected. Kinematic data were plotted using angle-angle, coupling-angle, and phase-plane diagrams. Accuracy statistics in conjunction with receiver operating characteristic curves were used to determine agreement between clinical observation and kinematic patterns. Results Kinematic patterns were consistent with clinical observation and definitions of typical and aberrant movement patterns with moderate agreement (kappa = 0.46–0.50; PABAK = 0.49–0.73). Early pelvic motion dominance in lumbopelvic coupling-angle diagram ≥59° within the first 38% of the movement represent observed altered lumbopelvic rhythm. Frequent disruptions in lumbar spine velocity represented by phase-plane diagrams with local minimum occurrences ≥6 and sudden decoupling in lumbopelvic coupling-angle diagrams with sum of local minimum and maximum occurrences ≥15 represent observed judder. Conclusion These findings further define observations of movement coordination between the pelvis and lumbar spine for the presence of altered lumbopelvic rhythm and judder. Movement quality of the lumbar spine segment is key to identifying judder. This information will help clinicians better understand and identify aberrant movement patterns in patients with non-specific low back pain