*4.1.2.2 Radiography*

Schwab et al. considers the radiographic method of spinal screening to be the traditional and "gold standard" method for the assessment and screening of patients with spinal deformities [28]. Furthermore, Schwab et al. suggests that radiography is an essential tool for the accurate diagnoses of spinal abnormalities/ deformities and accurately reveals the degree and severity of the problem [29].

In this method, an X-ray image is captured when a beam of X-ray light is passed through the spine and the amount of radiation emerging on the other side is recorded. Since the bones of the spine absorb the radiation and soft tissues allow it to pass through, a clear image of the spine is captured. McVey et al. suggests that the captured radiographic image provides essential information on spinal bone structure, which can be used to analyse individual vertebrae and the overall contour of the spine [30].

In addition to the assessment of spinal curvature, X-rays are also used to record and monitor the progression of spinal deformities and dysfunction [31, 32]. Therefore, in adolescent patients it is performed every few months in order to detect any changes in the progression of the spinal deformity.

The main drawback of the radiographic method of spinal assessment is associated with the increased radiation that has been found to increase the incidence of cancer in later years [33, 34]. Doody et al. in their retrospective cohort study estimated the carcinogenic risk and the patterns in breast cancer mortality among female patients with scoliosis [35]. This study included a large sample size (5,573 female patients with scoliosis, or abnormal curves). The results suggested that due to the high exposure to cumulative x-ray radiation of 10.8 cGy (from childhood to adolescence), breast cancer risk increased by 70%. Similarly, Beir in his review, reported that the exposure to radiation during periods of rapid growth, potentially amplified the deleterious biological effects [36].

Due to its high cost and risk of exposure towards harmful radiation, studies by van Niekerk et al. and Kilinç et al., recommended using alternative noninvasive methods for the assessment and screening of postural variables [37, 38]. In the next section, photogrammetry tools, together with methods to analyse postural variables are discussed. As stated by Furlanetto et al., the simplicity and convenience, has made the photogrammetry method very popular among clinical practitioners [39].

### *4.1.2.3 Photogrammetric method*

In the last two decades, the photogrammetric method of postural evaluation and its applicability has been widely reported in the literature [9, 39]. Low-cost, quantitative evaluation together with its use in reducing the exposure to radiation, makes this method much more feasible for healthcare practitioners to use within their clinical practice. The following research studies have assessed the reliability, and validity of photogrammetry together and its application in different scenarios. Souza et al. and Fortin et al. have proposed a number of diverse photographic methods for evaluating postural variables and conducting postural diagnosis [9, 40]. Several authors [41, 42] have reported the use of photographic methods for the quantification together with the reliability of measuring postural variables. Santos et al. (2009) reported good to excellent inter-rater reliability (interclass correlation coefficient [ICC] values were between 0.84 and 0.99) for the photographic measurement of 33 postural variables in standing in 122 normal healthy children aged 7–10 years [41].

However, Souza et al. in their study on measuring 20 postural variables found mixed results. The ICC values for inter and intra-rater reliabilities for trunk and hip angle were found out to be 0.62 (*p* value was 0.12) and 0.56 (*p* value was 0.43) respectively. The level of reliability of these two angles was thus classified

### *Posture and Back Shape Measurement Tools: A Narrative Literature Review DOI: http://dx.doi.org/10.5772/intechopen.91803*

as not acceptable. The ICC values for lower leg postural variables (bilateral hind foot angle) ranged from 0.74 to 0.86 (*p* < 0.05). This level of reliability was classified as good and acceptable. The interrater reliability for the remaining sixteen posture angles reported excellent ICC values (greater than 0.90). Except for the trunk and hip angles, the rest of the sixteen variables yielded non-repeatable intra-rater values. The authors of this study concluded that frontal-view postural variables, such as the alignment of the head, trunk and lower limbs, measured using the photography method were reliable for measuring various postural asymmetries.

Although numerous studies [9, 43, 44] have reported the photogrammetric method of posture analysis, the most common limitation is the inconsistency used in the data collection procedure. For example, the distance between the subject and the placement of the camera varied between studies. The body segment length increases or decreases depending on how close the camera is to the surface of the human body. Additionally, from 2D photographic methods, it is very difficult to study deformities which have a rotational component in the transverse plane [9, 45]. Similarly, in the sagittal plane, there is a possibility that the muscle mass of the erector spinae can obscures the median furrow of the back surface; thereby it is very difficult to study the true spinal curvature [46].

In summary, two-dimensional spinal assessment tools do not provide a complete description of the three-dimensional nature of the back and other spinal deformities. To obtain the detailed three-dimensional description of spinal deformities together with the information of the 3D back surface, various three-dimensional surface and posture measurements tools have been reported in recent years. In the following section, three-dimensional measurement systems (both tactile and nontactile methods) have been used to assess posture and back shape variables. These are reviewed below.

### **4.2 Three-dimensional analysis of posture and back shape**

In the last decade, three-dimensional analysis of posture and back shape has not only developed significantly, but its use in both the spinal research and clinical environment has also been extended to include both tactile and non-tactile instruments, which will be discussed below.

### *4.2.1 Tactile tools of measurement of spinal curvature*

### *4.2.1.1 Posturometer-S*

The Posturometer-S is a specially designed, electronic, objective, non-invasive body posture measuring device [47] (see **Figure 4**). This tool consists of three coupled systems: 'P' which is a pointer to indicate the position of a measured point (mechanical), an element to compute the position of the pointer in a three-dimensional space (electronic) and an 'informatique' which is used to analyse the results obtained. This system not only enables a practitioner to visualise the curvature of the spine in all three planes but also provides a quantitative description of the postural parameters.

Previous research [47, 48] has demonstrated not only the reliability of the posturometer but also its applicability in the assessment of posture in different age groups. Lichota et al. using the Posturometer-S examined the postures of 46 athletes who were aged between 20 and 24 years [49]. A total of four sports groups were examined, namely, handball (n = 16), athletics (n = 9), taekwondo (n = 5) and

**Figure 4.** *Schema of Posturometer-S device (source: Stacho*ń *et al. [47]).*

volleyball (n = 13). In this study, the 'Posturometer-S' was used to describe various angles of the spine, for example, lumbar lordosis, thoracic kyphosis, upper thoracic segment (α angle), the thoracolumbar segment (β angle) and the lumbosacral segment (γ angle). The highest values for α angle, β angle and γ angle were reported in volleyball (15.2°), athletics (12.6°) and taekwondo (14.0°) groups, respectively. The lowest values for the α angle, β angle and γ angle were observed in athletics (12.4°), handball (8.8°) and handball (8.0°) groups, respectively. The authors contended that posture was affected by the specific type of sports training and that the type of sport influenced the type of posture. The main limitation the authors reported in the study was that the Posturometer-S was not user-friendly, consumes more space in the room and requires a thorough understanding of the equipment together with training before it can be used.
