**1. Introduction**

The purpose of this chapter is to share with scoliosis professionals the biomechanics and design of the Rigo Chêneau brace. A historical background of the Rigo Chêneau brace is provided to show the evolution and improvements in it over the last three decades, particularly changes outlined since 2005, which have led to good fit and function. Equally important to the end result is good patient follow-up care and brace quality control by the referring MD, physical therapist and orthotist.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The original brace was called the Chêneau Toulouse Munster (CTM) brace after Dr. Jacques Chêneau of Toulouse, France and Professor Matthias of Münster, Germany who first presented it in 1979. Later, the brace came to be known as the Chêneau brace. In 1996, Dr. Chêneau outlined the hand-casting procedures and discussed the three-curve and four-curve Chêneau brace types, outlines in his manual named "Orthese de Scoliose" [1, 6] which outlined the hand-casting procedures and discussed the three-curve and four-curve Chêneau brace types (**Figure 1**).

**Figure 1.** The three-curve and four-curve casting technique for providing optimal fit at the iliac crests in (a) and (b). The orthotist elongates the patient by applying an extension force at the axillas in (c). The negative cast cut-and-position technique of correction and alignment of the Chêneau brace in (d)–(f) [6].

The original Chêneau brace had two brace designs. These were based on the curve classification from Katharina Schroth, which treated scoliosis as a three-curve pattern or four-curve pattern. Therefore, we had a three-curve Chêneau brace and the four-curve Chêneau brace (**Figure 2**).

The original brace was called the Chêneau Toulouse Munster (CTM) brace after Dr. Jacques Chêneau of Toulouse, France and Professor Matthias of Münster, Germany who first presented it in 1979. Later, the brace came to be known as the Chêneau brace. In 1996, Dr. Chêneau outlined the hand-casting procedures and discussed the three-curve and four-curve Chêneau brace types, outlines in his manual named "Orthese de Scoliose" [1, 6] which outlined the hand-casting procedures and discussed the three-curve and four-curve Chêneau

The original Chêneau brace had two brace designs. These were based on the curve classification from Katharina Schroth, which treated scoliosis as a three-curve pattern or four-curve pattern. Therefore, we had a three-curve Chêneau brace and the four-curve Chêneau brace (**Figure 2**).

**Figure 1.** The three-curve and four-curve casting technique for providing optimal fit at the iliac crests in (a) and (b). The orthotist elongates the patient by applying an extension force at the axillas in (c). The negative cast cut-and-position

technique of correction and alignment of the Chêneau brace in (d)–(f) [6].

brace types (**Figure 1**).

170 Innovations in Spinal Deformities and Postural Disorders

**Figure 2.** An old style, four-curve handmade Chêneau brace from 1999, Malaga, Spain. A numbering system was utilized by Dr. Chêneau to identify all the pressure and expansion areas [2].

In the late 1990s, Dr. Manuel Rigo (MR) of Barcelona found that these two designs were insufficient for the distinct types of curve patterns. As a result, the King classification was adapted for the Chêneau brace for a few years. However, MR found that there were brace failures with the King classification when it was used for brace design. The King classification was developed for surgeons to decide on the level of spinal fusion during surgery, and not specifically for bracing. Because of these failures, MR developed a classification to guide the brace design [3], which was first presented by MR et al. in 2010. This was presented later by Grant Wood at the International Society for Prosthetics and Orthotics (ISPO) of 2010 in Leipzig, Germany [4].

Since the original brace in 1979, various Chêneau brace derivatives were developed. The first author of this paper, GW, began in 1995 with the original Chêneau brace, under the training and teachings of Dr. Chêneau. Dr. Chêneau and Dr. Rigo were providing brace modification workshops in Barcelona and Sevilla Spain during the late 1990s. During these workshops, the shape of the original Chêneau brace changed significantly, mainly through modifications suggested by MR, including significant increases in the size and locations of plaster expansion zones and pressure areas. These modifications led to the familiar large flowing and asymmetrical shapes that are more commonly seen today.

In 2012, due to the wide range of brace standards and various levels of quality of Chêneau braces using the Rigo principles, GW, the main author, named his brace according to his own methodology and hand modifications aimed at addressing the complexities of the original design, and named the brace Wood Chêneau Rigo (WCR) brace.

The WCR brace evolved from the original Chêneau brace (1995), which was subsequently refined using the Rigo classification of scoliosis, and hand modifications aimed at addressing the complexities of the original design.

The WCR brace incorporated the best of modern CAD CAM and "old school" hand modifications. Generally speaking, technical advances in brace design and production have increased productivity, albeit at the cost of individualization to each patient's anatomy, curve pattern, and preferences, the lack of which can degrade the brace's fit and function. For this reason, the WCR brace has, since its inception in 1995, applied the most critical patient modifications by hand.

The differences between the original Chêneau brace and the author's Chêneau-Rigo handmade type brace are the following:


In 2017, due to the multiplicity of versions and variations in the quality of the Rigo Chêneau type brace, Dr. Rigo, Grant Wood and Luke Stikeleather founded the Association of Rigo-Chêneau specialists (ARCS), which has the goal of maintaining and providing a standard of quality and education for orthotists who have practiced these principles.

The Rigo Chêneau type brace is a corrective orthotic device which must be individualized to each patient's specific curve pattern and other unique body characteristics.

It is not an orthopedic product but rather a corrective concept for the specific use in the conservative treatment of scoliosis.

A 3D scan or handmade cast is used to capture the patients exact body shape and anatomy. The scan or cast then produces a positive mold that is rectified to provide a 3D corrected positive mold, which in turn is used to adapt the thermoplastic to provide the finished brace.

Using the handmade original tech, a 3D corrected positive mold is created to provide specific pressure areas or pads of contact, and expansion areas or rooms. These pressure areas or pads have specific levels, orientations, depths and shapes. The pressure areas are generally located on the convexities and prominences of the scoliosis body. Contacts or pads are individually oriented in space and shaped to provide 3D correction (**Figure 3**).

The expansion areas, or rooms, are not windows where a simple hole is cut out of the plastic, but instead, actual buildups of significant space created in the original positive mold. They are generally located in the concavities and prominences of the scoliotic body. Expansion rooms are for tissue migration, growth and breathing movements, thus converting a rigid brace into a dynamic brace [5].

The Rigo Chêneau type brace is a thermoplastic brace with a ventral opening and Velcro closures. It follows many of the original 3D concepts of Dr Chêneau, and utilizes the Rigo classification of scoliosis and brace design.

**Figure 3.** A WCR brace modified and fit by the main author, shows the left lateral, anterior, posterior and right lateral views of the patient with 3D correction in a C2 type brace using the Rigo classification of scoliosis [3].
