The role of the paraspinal muscles in the development of adolescent idiopathic scoliosis based on surface electromyography and radiographic analysis.

BACKGROUND: Patients with idiopathic scoliosis commonly present with an imbalance of the paraspinal muscles. However, it is unclear whether this muscle imbalance is an underlying cause or a result of idiopathic scoliosis. This study aimed to investigate the role of paraspinal muscles in the development of idiopathic scoliosis based on surface electromyography (sEMG) and radiographic analyses. METHODS: This was a single-center prospective study of 27 patients with single-curve idiopathic scoliosis. Posteroanterior whole-spine radiographs and sEMG activity of the erector spinae muscles were obtained for all patients in the habitual standing position (HSP), relaxed prone position (RPP), and prone extension position (PEP). The Cobb angle, symmetrical index (SI) of the sEMG activity (convex/concave), and correlation between the two factors were analyzed. RESULTS: In the total cohort, the mean Cobb angle in the HSP was significantly greater than the mean Cobb angle in the RPP (RPP-Cobb) (p < 0.001), whereas the mean Cobb angle in the PEP (PEP-Cobb) did not differ from the RPP-Cobb. Thirteen patients had a PEP-Cobb that was significantly smaller than their RPP-Cobb (p = 0.007), while 14 patients had a PEP-Cobb that was significantly larger than their RPP-Cobb (p < 0.001). In the total cohort and two subgroups, the SI of sEMG activity at the apex vertebra (AVSI) in the PEP was significantly greater than 1, revealing significant asymmetry, and was also significantly larger than the AVSI in the RPP. In the RPP, the AVSI was close to 1 in the total cohort and two subgroups, revealing no significant asymmetry. CONCLUSION: The coronal Cobb angle and the SI of paraspinal muscle activity in AIS patients vary with posture changes. Asymmetrical sEMG activity of the paraspinal muscles may be not an inherent feature of AIS patients, but is evident in the challenging tasks. The potential significance of asymmetric paraspinal muscle activity need to be explored in further research.

Acceleration of Cathode Interfacial Kinetics by Liquid Organosulfides in Lithium Metal Batteries.

Great efforts have been made to tackle the issues of the shuttle effect and kinetics hysteresis in lithium-sulfur (Li-S) battery, but few on tuning the reaction path of sulfur cathode. Herein, we report a strategy to replace inorganic sulfur with liquid organosulfide and construct a novel liquid-liquid interface between cathode and electrolyte, which effectively inhibits the shuttle effect and simplifies the solid-liquid-solid conversion reaction to only liquid-solid process, thus greatly improving the reaction kinetics. The Li|PTS half-cell exhibits excellent cycling stability at 0.5 C, with a capacity retention of 64.9 % after 750 cycles. The Li|PTS pouch cell with a high PTS loading of 3.1 g delivers a maximum capacity of 997 mAh and maintains 82.1 % of initial capacity after 50 cycles at the current of 100 mA. This work enriches the reaction mechanism of Li-S batteries and provides new insights for the development of interphase chemistry in the design of cathodes.