The cause of spinal deformity is a problematic developmental process, the outcome of which can be altered with appropriate intervention and there is some evidence that scoliosis is reversible [1–3]. Opinions vary about the efficiency of conservative treatment of scoliosis [4, 5] with the efficiency of bracing continuing to be questioned [6–8]. The differences in the results of conservative treatment occur because of: a lack of standardisation of protocols and data analysis, a lack of reliable information about the natural history of untreated scoliosis [9]; as well as variations in brace type and lack of standardisation of application [10]. There are still many unknowns about brace treatment, which are required to determine its effectiveness [8] for example: the number of hours a day the brace should be worn to achieve optimum results [11]; what is the best weaning protocol and when weaning should start [8, 12]; and how much “in brace” correction is needed to obtain good results. The primary aim of conservative scoliosis management is to stop curvature progression [5, 8, 13–15] and thus to avoid surgery [16]. Other important aims are the improvement of pulmonary function, treatment of pain, improvement of the aesthetic appearance [17, 18], postural balance and reduction of psychological distress.

High correction bracing has been shown to have favourable outcomes when the patient is compliant [5, 14, 19–22]. Wearing the brace for 23 hours a day is significantly more successful than wearing the brace for between eight and 16 hours per day [10]. Longer hours of brace wear are associated with greater benefit [23]. Compliance and primary in- brace correction are the two most important variables associated with good brace outcomes [5, 24, 25].

There are differences of opinions as to whether exercise alone is a useful intervention for AIS [26–28]. Exercise has been shown to improve signs and symptoms of scoliosis without surgery [1, 2, 5, 27, 29, 30] by maintaining the flexibility of the spine, which is important for rigid curves that progress rapidly. In a comprehensive systematic review of the literature, Negrini et al. [31], found that exercise reduces the curve progression rate and reduces brace prescription, with very specific exercises decreasing the progression of scoliosis to the point where a brace is not required [31]. Non-specific exercises are not effective in treating AIS [32]. The only randomised controlled trial (RCT) on exercise in AIS included 80 subjects, 15 (±4) years of age, with a 24° (±12°) Cobb angle. After six months of treatment, including gymnastic exercises, postural training and auto-correction, the Cobb angle in the exercise group improved 15°. Noteworthy here is that the mean Cobb angle was not large enough to brace and the study included only six months of treatment [33]. There is therefore very little evidence showing that conservative management on 25-50° curves improves Cobb angles.

The diagnosis and treatment of AIS can have significant psychological consequences for affected individuals [34] as the diagnosis of AIS comes at a time when concerns with appearance and bodily function are at their peak [4]. The impact of scoliosis is particularly marked if a brace is indicated as bracing for IS is a stressful experience [34, 35] with psychological issues being blamed for the lack of compliance to wearing a brace [4, 36]. Scoliosis is thus seen as a risk factor for impairment of quality of life (QoL) in adolescents [34, 37].

Brace treatment can negatively affect health related quality of life (HRQoL) in scoliotic patients [38]. The SOSORT 2005 consensus paper, reported that only 1,48 percent of scoliosis studies included a measure of HRQoL [18]. Several reviews of the literature show that bracing does not affect the HRQoL in scoliotics [39] however some show that it does [34, 40]. The Brace Questionnaire (BrQ) was designed to test HRQoL in brace treated scoliosis patients [38] and its use shows that by the end of conservative management, HRQoL deteriorates [41]. One possible explanation is the stress reported during conservative treatment with an orthotic device [35]. The impact of the brace on the self and body image is the main contributing factor to the stress [38]. Continuous monitoring of stress levels allows the possibility of modifying treatment in order to maintain good compliance [42].

Long term studies on conservative therapies to stabilise or reverse scoliosis are required, before it progresses to lifelong difficulties. The aim of this study was to: determine the effect of compliance to the Rigo System Cheneau (RSC) brace and a specific exercise programme on IS curvature; and to compare the quality of life (QoL) and psychological traits of compliant and non- compliant subjects.

The results of this study indicate that compliance to a specific exercise programme and wearing the RSC brace can improve curvatures and signs and symptoms of AIS. The natural history of scoliosis was altered in the compliant subjects with non-compliance resulting in significant progression of the curvatures. Some studies have shown that conservative management of bracing and exercise has no effect on the natural history of scoliosis while others have shown that conservative management is effective [4, 23], but compliance was not reported on in these studies. The importance of compliance is supported by Landauer et al. [24] and Weinstein et al. [23], and should be monitored in future studies [23].

The risk of progression of the curvatures in both groups of subjects was high, 70-78 percent. The mean in-brace correction was 44.5% in the compliant group and 35.8% in the non -compliant group, which was not statistically different with similar in-brace corrections being reported [56, 57]. Compliance and initial correction effect in the brace are the two most important variables associated with good brace outcomes [5, 24, 25, 58]. The reason for the good in-brace correction in this study is probably the good three dimensional design of the RSC brace [59].

A study by Landauer et al. [24] has similar results to this study. They advised full time Cheneau bracing and weaned the subjects at Risser 5 over a six month period. They did not state how many hours the brace was actually worn, however, they did use a compliance score. The final overall outcome of their study, including all subjects, was that the thoracic curve improved three degrees only, not a successful result. However, when the subjects were divided into compliant and non compliant groups, then the study was very successful, as high early in-brace correction (40% or more) and good compliance achieved a correction of seven degrees in the Cobb angle. Low early correction (less than 40%) and good compliance resulted in stabilisation of the curvatures. Poor compliance with a high or a low initial correction resulted in progression of the Cobb angle [24] therefore emphasising the importance of evaluating compliance which is more important than in-brace correction.

The compliant group in this study had improved Cobb angles, angle of vertebral rotation and angle of trunk rotation (ATR), by wearing the brace 21.5 hours per day. Wearing the brace for 12 hours in the non- compliant group resulted in progression of the curvatures. Many Cheneau brace studies do not mention the number of hours the brace was worn [17, 54, 60, 61] but good brace compliance has been shown by a number of studies to have good outcomes [21–24, 62–65]. Recording the brace wearing hours was one of the challenges of this study. Using a compliometer or thermobrace, not currently used in South Africa, would have been more accurate in measuring actual brace wearing hours. Subjects’ diaries were checked frequently by the first author and parents for the record of brace hours. A study by Takemitsu et al. [66] showed that patients complied with 75 percent of a prescribed routine and on average over-reported their hours of brace wear to their physicians. The actual brace hours were measured using a compliance monitor. A study by Donzelli et al. [67] in which they used a temperature sensor (Thermobrace) showed compliance to be higher than previously reported with brace prescription being 16-23 hours per day and more than half the patients had 90 percent compliance.

The exercise programme was completed 3.9 times a week by the compliant group and 1.7 times a week by the non -compliant group This prescription of four to five times a week for 20-25 minutes is similar to the Schroth method [68], Dobosiewicz method [69], and SEAS and Side Shift method [26].

The Cobb angles were significantly reduced in the compliant group with the worst/major Cobb angle significantly improving (10.19 degrees), thus the natural history of AIS was altered. In the non -compliant group there was significant progression of the curvatures (5.5 degrees), following the natural history of scoliosis and three progressed to surgery. Supporting this study is a small study by Wood [59] on 23 subjects, with Cobb angles greater than 30 degrees, using the Cheneau brace over a four year period with a progression risk of 68 percent. Compliance was not measured in the Wood study nor was the physiotherapy described. Wood [59] showed that the major Cobb angle improved a mean of 13.2 degrees and the minor Cobb angle improved eight degrees at the end of brace wearing. Physiotherapy has been shown to have favourable outcomes in scoliosis patients and Rigo claims that physiotherapy can improve the actions of the Cheneau brace, by making the curve more flexible and preventing muscle atrophy [17, 70]. Cinnella et al. [71] using the Cheneau brace showed a 23 percent correction in Cobb angle at the end of a mean treatment period of 4.5 years, and after five years the correction was 15 percent but compliance was not monitored. Other studies on the Cheneau and RSC braces only show stabilisation of curvatures and reduction in children requiring surgery [6, 14, 64, 65, 72–74].

Kyphosis angles improved in the compliant group and deteriorated in the non- compliant group, and therefore the sagittal profile improved in the compliant group. The compliant group is similar to several studies that show normalisation of kyphosis and lordosis with the Cheneau brace [13, 17, 60]. In many Cheneau brace studies however, the sagittal profile is not mentioned, [24, 56, 59, 61, 65, 71]. The RSC brace allows sagittal normalisation because of its physiological profile in the sagittal plane and every trunk section is aligned to allow a normal sagittal profile [17, 75].

The angle of axial rotation predicts the incidence of progression of a curve better than the size of the Cobb angle [76]. In this study all apical vertebra were significantly reduced in rotation in the compliant group p < 0.0001 in the worst/major curves which is similar to the study by Wood [59]. The RSC and the Cheneau brace has also been shown to improve the wedge deformity of the apical vertebra, by over 50% in some cases [77, 78].

Scoliometer readings improved significantly in the compliant group. Similarly Kinel et al. [63, 79] showed that girls with AIS, wearing a Cheneau brace, revealed less clinical deformity than a group of non- treated girls with similar radiological deformities. Other studies using the Cheneau brace have shown cosmetic improvements in the deformity [13, 17, 59, 60, 80].

The peak flow changes in the compliant group improved significantly (by a mean of 20 percent) more than the non -compliant group (by nine percent). The Dobomed method has also been shown to improve exercise efficiency significantly using ergospirometry [69, 81]. Other studies using outpatient or in-patient Schroth method have shown significant improvements in vital capacity (VC) [82–85]. Dos Santos Alves et al. [86] showed that aerobic exercises three times a week for an hour, over a period of four months, resulted in a significant improvement in FVC, FEV1, inspiratory capacity, expiratory reserve volume and in respiratory muscle strength [87]. Spirometry is the method of choice to identify any changes in the course of a respiratory disease [88] although a Mini Wright peak flow meter was used here to measure FEV1, as it is simple, portable, reproducible and practical to use clinically [89, 90].

Peak height was reached between 3.46 (±0.5) to 4.03(±0.6) years after menarchy. Weaning the subjects out of full time bracing, at the end of the study, occurred once height had been static for six months and as close to Risser 5 as possible. Weaning out the brace in the compliant group of this study started at the mean age of 17.14 (±0.6) years, which is later than most studies, in order to prevent progression, previously reported and postural collapse [12, 91]. The fact that peak bone mineralization and peak muscle strength occurs at 25, and peak ligamentous stability occurs in the early 20’s [92], was considered when deciding on weaning. Bracing is sometimes considered ineffective, when actually the subjects have just been weaned out too early or too quickly [93]. The optimal weaning process is not known and has not been standardised [8, 12] and therefore was not included in this study. Skeletal maturity measures are not accurate enough to predict spinal growth potential in AIS [94].

One subject stopped wearing the brace in the non- compliant group. Psychosocial and body image disturbance are less marked in patients with good social and family functioning, as well as patients who exercise regularly [40] and this is similar to the compliant group in this study. The compliant group had larger Cobb angles than the non compliant group at baseline, therefor the severity of the scoliosis as measured by Cobb angle was not related to a poorer quality of life. Other Cheneau brace studies have shown the brace negatively affects quality of life [95–97]. Quality of life issues may be related to psychosocial coping mechanisms more than the physical deformity and its consequences. Support for AIS patients in group or individual sessions prevents psychosocial impairment, body image disturbances and should be included in holistic management plans [34, 40]. Programmes to address personal, group and family issues may improve QoL, promoting compliance [43]. In this study emotional function was lower in the non- compliant group, and subjects did not believe that the brace was beneficial, had low self esteem and low social function. Lindeman and Behm [98], showed that non- compliant girls did not expect to succeed in dealing with scoliosis, they were anxious about possible failure, had low self- esteem and did not seek social support.

Non compliance to the intervention resulted in progression in curvatures. These subjects had a poorer quality of life and seemed to need psychosocial support to improve compliance and therefore treatment outcomes. This should be included as part of a management programme, as subjects do not generally seek help. Continuous monitoring of stress and QoL needs to be done, which will allow modification of the treatment and maintain good compliance [42] with regular consultations with a psychologist and family counselling.

The personality trait questionnaire revealed, that the compliant group was more emotionally mature, stable and realistic than the non- compliant group, which was more emotionally immature and assertive (Factor C). Higher scores in Factor C (compliant group) reveal emotional stability, control, and high ego strength [47]. These patients appear calm, unruffled, behave in an adult and rational way, they are realistic, constant in interests, responsible, distinguish between emotional needs and reality, and adjust to facts. High Factor C scores also correlate with positive family relationships and leadership [45]. Lower Factor C scores, in the non- compliant group, indicated emotional instability and low ego strength [45]. They reveal an inability to control their emotions, impulses and to find satisfying and realistic ways of expressing them. They are easily angered, are more frequently dissatisfied with their family and school, find it difficult to restrain themselves and are discouraged by their inability to meet good standards of behaviour. They are easily perturbed, confused, changeable in attitudes and interests. They evade responsibility, give up easily, tend to worry a lot, have irrational fears and get into fights and problem situations. They can experience severe adjustment problems if subjected to regimentation and stress [45] with bracing being stressful [35]. These factors may explain their lack of compliance.

Psychological support during this adjustment to bracing and exercise phase as well as during the treatment therefore seems to be essential. The results of the personality questionnaire compare well with the results of the BQ, which showed that the non- compliant subjects had a poorer QoL.

Other traits from the questionnaire, revealed marginally significant differences in that the compliant group was more obedient, mild and dependant (Factor E), tender minded, sensitive, protected (Factor I) relaxed, and composed (Factor Q₄). The non- compliant group was more aggressive, rebellious, dominant (Factor E), practical tough- minded and tense (Factor I) driven, irritable, and frustrated (Factor Q₄). In Factor E, lower scores, in the compliant group, show traits that are more accommodating, more compliant and easily influenced [45]. High scores in Factor E seen in the non- compliant group, show traits of stubbornness, and are headstrong, arrogant and disobedient.

This study has determined the personality traits of compliant and non- compliant subjects and these traits can be used to predict compliance of a subject. Should a patient be predicted to be non -compliant using the HSPQ, at the beginning of treatment, then appropriate interventions, such as regular individual and family counselling could be implemented at the beginning of the programme in an attempt to improve compliance. The up to date personality questionnaire now recommended by the editors of the HSPQ is the “16PF Adolescent Personality Questionnaire”, by Scheurger [99], for 11-22 year olds.

Good compliance to a conservative treatment programme of the RSC brace and a specific exercise regime resulted in a significant improvement in curvatures, whereas poor compliance resulted in progression of curvatures. Predicting compliance using personality traits at the start of a conservative treatment programme could indicate what interventions are required to improve compliance. Further studies are required to determine the long term effects of this conservative treatment programme.

LR is a physiotherapist in private practice with a PhD degree from the University of the Witwatersrand Johannesburg South Africa.

AS is an Associate Professor with a PhD in the Department of Physiotherapy, School of Therapeuitc Sciences, Faculty of Health Sciences University of the Witwatersrand Johannesburg South Africa.

JP is an Associate Professor with a PhD in the Department of Physiotherapy, School of Therapeutic Sciences, Faculty of Health Sciences University of the Witwatersrand Johannesburg South Africa.