**The Principles and Biomechanics of the Rigo Chêneau Type Brace Type Brace**

**The Principles and Biomechanics of the Rigo Chêneau**

DOI: 10.5772/intechopen.70381

Grant I. Wood and Manuel Rigo

Grant I. Wood and Manuel Rigo Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70381

#### **Abstract**

All scoliosis braces bearing the name "Chêneau" as part or all of their designation share a common history, originating in 1979 with the Chêneau Toulouse Munster (CTM) brace, developed by Dr. Jacques Chêneau and Professor Matthias of Munster. Since then, several variations of this brace have evolved to enhance support/correction of scoliosis in three dimensions. Design features based on the Rigo classification of scoliosis and further modifications by the co-author led to the Rigo Chêneau type brace. This is a dynamic brace, with expansion rooms to accommodate tissue migration, growth and breathing movements. The brace by the authors is hand-made and customized to the curve pattern, skeletal maturity, flexibility and structural component of each individual. It applies both de-torsional forces and three-point pressure systems to improve spinal alignment in all three planes. It is also designed to work synergistically with Schroth physiotherapeutic scoliosis specific exercises to optimize effectiveness of a conservative approach.

**Keywords:** scoliosis bracing, Wood Chêneau Rigo (WCR) brace, Schroth physical therapy, Rigo Chêneau type brace, Rigo classification of scoliosis and brace design


*2.2. Fruit Processing*

Kiwifruits (*Actinidia deliciosa* cv. "Hayward") at full maturity were purchased in November 2021 from a local supermarket in Galati County, Romania. The fruits were sorted and processed immediately. Once they arrived at the laboratory, the fruits were washed with distilled water, and peels were separated from the fruits. The fruits were further cut in half and squeezed using a juice extractor (Stainless Steel Fruit Vegetable Juice Extractor Juicer Squeezer, Guangdong, China). The fresh material, specifically peels and pomace, was used for initial phytochemical content and antioxidant activity analyses.

### *2.3. Extraction of Phytochemicals from Fresh Kiwi Samples*

In order to characterize the freeze-dried powders of the fresh material, a subsequent extraction was performed using a solid–liquid ultrasound-assisted method with two different solvents. The design of extraction procedures was based on a comprehensive comparison of both lipophilic and hydrophilic profiles by using two different combinations of solvents: a mixture of ethanol and water (ratio of 70:30, *v*/*v*) and *n*-hexane–acetone (ratio 1:3, *v*/*v*). The fresh material was extracted with the corresponding solvent solutions in a solid–liquid ratio of 1:10 by mixing and ultrasound treatment at 35 ◦C for 30 min. Each extraction was repeated twice to obtain enriched extracts.

### *2.4. Customized Design to Develop Kiwi-Based Ingredients Enriched with Probiotics*

About 50 g of fresh material (kiwi peels and pomace) was added to ultrapure water in a ratio of 1:2 and mixed by homogenization (ProBlend Crush Blender, Global Headquarters Netherlands, Eindhoven). Prior to inoculation, the mixtures were enhanced with different flours, i.e., black rice and buckwheat (20%), and allowed to hydrate, followed by pH adjustment to 5.0 with 1.0 N NaOH. The designed samples were coded as follows: KP (freeze-dried kiwi peels), KBR (freeze-dried kiwi pomace and black rice flour), KPB (freezedried kiwi pomace and buckwheat flour), and KPO (freeze-dried kiwi pomace). All samples were sterilized using a UV lamp and inoculated with 2% *L. casei* 431® and freeze-dried (CHRIST Alpha 1–4 LD plus, Osterode am Harz Germany) at −42 ◦C under a pressure of 10 Pa for 48 h. Afterwards, the powders were collected and packed in glass containers and kept at 4 ◦C until further analysis.

### *2.5. Total Polyphenol (TPC) and Total Flavonoid (TFC) Analysis*

Spectrophotometric methods were used for the TPC and TFC evaluation by using the Folin–Ciocâlteu reagent and aluminum chloride methods, respectively, as described by Milea et al. [25]. For TP content, from each sample extract, a volume of 0.2 mL was diluted with 15.8 mL of distilled water, followed by the addition of 1 mL of Folin–Ciocâlteu reagent and 3 mL of 20% Na2CO3. The mixtures were left to stand for one hour in the dark to react, followed by reading the absorbance at λ = 765 nm (Jenway Scientific Instruments, Essex, UK). TP was expressed as mg gallic acid equivalents/g dry weight (mg GAE/g

DW) using a calibration curve. For TF evaluation, a volume of 0.25 mL from each extract was sequentially mixed with 0.075 mL of sodium nitrite (5%), 0.15 mL of 10% AlCl3, and 0.5 mL of 1 M NaOH. The absorbance of the mixtures was immediately measured at 510 nm against the suitable blank. TF was expressed in mg catechin equivalents (CE) per g of dry powder (mg CE/g DW).

### *2.6. Total Monomeric Anthocyanin Content*

Due to the special formulation of the KBR sample, which contained freeze-dried kiwi pomace and black rice flour, the total monomeric anthocyanin content (TAC) was assessed using the official AOAC method [26] and expressed as mg cianidin-3-O-glucoside equivalents/g DW (mg C3G/g DW).


**4. Conclusions**

The results of this study provide several insights into a nanoparticle engineered to be an environmentally friendly alternative to solid silver core nanoparticles. Our data shows that the use of lignin as the nanoparticle core could be a viable alternative, as it did not pose a significant toxicological hazard to our test organism. Since our reported toxicity was similar to other findings when compared on the basis of silver content, the toxicity of silver-enabled nanoparticles may be predictable, based on the silver concentration of the particle. Ionic silver and PDAC alone were the most toxic components of the formulation, which may be attributed to their higher diffusivity and propensity to interact with cell membranes relative to silver and/or PDAC associated with the particle. The inclusion of PDAC not only adds antimicrobial activity to the particle, but also seems to delay the release of silver ions, so in situations where time release of antimicrobial agents is desired, stabilizing the particles with PDAC may be warranted. This data also encourages further development of similar nanomaterials to minimize their impact on the environment, as well as testing the current particle under environmentally relevant conditions to evaluate toxicity. One way of reducing the environmental impact of these engineered nanomaterials is to design them in a way to minimize the release of soluble components, or to replace these components with less toxic ingredients. We are presently investigating the use of an alternative nanoparticle coating which is biologically derived, that may have the potential to be less toxic in comparison to PDAC.

## **5. Associated Content**

#### *Supplemental Information Is Available for This Publication*

Representative images of zebrafish with and without significant developmental impacts; Average zeta potential and hydrodynamic diameter measurements for particle-containing formulations over a five day period; Metadata associated with zeta potential measurements; Concentration-response curves for formulation components and dialyzed materials based on zebrafish mortality at 120 hpf; Modeled concentration-response curve for the reference material silver nitrate based on zebrafish mortality at 120 hpf; Visual MINTEQ output for all silver-containing formulations.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2079-6382/7/2/40/s1, Figure S1: Representative images of zebrafish with and without significant developmental impacts, Figure S2: Average zeta potential and hydrodynamic diameter (HDD) of particle formulations over a five day period in fishwater. Figure S1a,b are average zeta potential measurements for the formulation components (a) and the dialyzed formulations (b), and Figure S1c,d are the average HDD measurements for the formulation components (c) and the dialyzed formulations (d), Figure S3: Concentration-response comparisons for formulation components (a) and dialyzed materials (b) based on zebrafish mortality at 120 hpf (a) Significant differences (*p* ≤ 0.05) existed between materials in the formulation component treatments. The lignin particle exhibited the lowest toxicity, followed by silver, and PDAC. (b) No significant differences (*p* > 0.05) existed in the dialyzed sample treatments. Comparisons included the two full formulations (NP + Ag + PDAC) and the three NP + Ag formulations, Figure S4: Concentration–response curve for silver nitrate based on zebrafish mortality at 120 hpf, Figure S5: Frequency of delayed hatching in zebrafish embryos exposed to Ag+ as silver nitrate in fishwater. Asterisk represents significant increase (*p* ≤ 0.05) relative to unexposed (control) fish embryos, Figure S6: Frequency of delayed developmental progression in zebrafish embryos exposed to lignin nanoparticles in fishwater. Asterisk represents significant increase (*p* ≤ 0.05) relative to unexposed (control), Table S1: Metadata associated with zeta potential measurements.

**Author Contributions:** Alexander P. Richter and Orlin D. Velev conceived the materials, Cathryn G. Conner synthesized and provided the materials, Bryan J. Harper and Stacey L. Harper designed the experiments and contributed to the analysis of the data and Cassandra E. Nix performed the toxicological experiments, contributed to the data analysis and wrote the paper.

**Acknowledgments:** We would like to thank Alicea Meredith, Lindsay Denluck and Teresa Peterson for their assistance on the project and the Sinnhuber Aquatic Research Laboratory (Grant #P30 ES000210) for providing the zebrafish embryos. This work was supported by the United States Department of Agriculture National Institute of Food and Agriculture (USDA-NIFA), Grant 2013-67021-21181, partially supported by an Oregon State University Agricultural Research Foundation Grant (ARF8301A), as well as a grant from the National Institute of Environmental and Health Sciences (Grant # R01ES017552) to Stacey Harper. Alexander P. Richter thanks the Lemelson Foundation and the Lemelson-MIT program for support. We also acknowledge the support provided to Cathryn G. Conner by the Molecular Biotechnology Training Program (MBTP) sponsored by the National Institutes of Health and the Graduate School at North Carolina State University (5 T32 GM008776-15).

**Conflicts of Interest:** The authors declare no conflict of interest.