**1. Introduction**

The Chiropractic BioPhysics® (CBP®) technique was invented in 1980 by Donald D. Harrison, a chiropractor who was also educated in engineering and mathematics [1]. After reading the 1974 paper by Panjabi [2] on the recommendation for the use of a Cartesian coordinate system to accurately describe the movement of body joints as rotations and translations around an origin, he applied this concept to upright human posture (**Figures 1** and **2**) [1, 3]. Instead of being applied to a single joint, Harrison presented the displacement of the head, thorax and pelvis as rotations and translations of the main masses of the body, with spinal coupling patterns that occur within the corresponding spinal junctions between the adjacent body masses for each particular movement/position.

**Figure 1.**

*Human posture described as rotations of the head, thorax, and pelvis about the x, y, and z-axes of the Cartesian coordinate system (Courtesy: CBP seminars).*

**Figure 2.**

*Human posture described as translations of the head, thorax, and pelvis along the x, y, and z-axes of the Cartesian coordinate system (Courtesy: CBP seminars).*

In an attempt to model the upright neutral sagittal spinal position, Don Harrison along with his son Deed Harrison and other colleagues performed a strategic set of studies. Although many research groups have attempted to model the shape of the normal human spine in the sagittal plane, few have done so as comprehensively and

### *Restoration of Cervical and Lumbar Lordosis: CBP® Methods Overview DOI: http://dx.doi.org/10.5772/intechopen.90713*

systematically as the Harrison group [4–11]. Elliptical shape modeling of the path of the posterior longitudinal ligament along the posterior vertebral body margins was chosen due to the ease of clear identification of these spine landmark points and for the ability to easily make measurements of spine segmental and total angle of curvature on patient radiographs to compare patient measurements to model predictions. Modeling was performed on radiographic samples of asymptomatic participants. Computer iterations of spinal shape modeling was applied to determine best-fit geometric spine shapes by fitting various ellipses of altering minor-to-major axes ratios to digitized posterior vertebral body corners on samples of radiographs of the cervical [4–6], thoracic [7, 8], and lumbar spinal regions [9–11] (**Figure 3**).

The Harrison normal spinal model (**Figure 3**) features a circular cervical lordosis, and portions of an elliptical curve for both the thoracic kyphosis (more curvature cephalad), and lumbar lordosis (more curvature caudad). Consequently, features of the normal human spine reveal that the opposite thoracic and lumbar curves meet together at the thoraco-lumbar junction being essentially straight; the upper, deeper curve of the upper thoracic spine reflects oppositely at the cervico-thoracic junction (between T1 and T2) and continues into the cervical lordosis; the lower lumbar spine increases its lordotic alignment having two-thirds of its curve between L4-S1 as it meets the forward tilted sacral base. The spine is modeled as vertical in the front view. The spine alignment is easily quantified by repeatable and reliable methods from measuring its position from standing X-rays [12–16] (**Figure 3**).

The Harrison normal spinal model has been validated in several ways. Simple analysis of alignment data on samples of the normal, asymptomatic population has been done [4–11]. Comparison studies between normal samples to symptomatic samples [4, 17]; as well as between normal samples to theoretical ideal models have been done [4, 5, 8, 10]. The statistical differentiation of asymptomatic subjects from symptomatic pain group patients based on alignment data has been performed [6, 11].

### **Figure 3.**

*Left: The Harrison normal spine model as the path of the posterior longitudinal ligament in the sagittal plane. Right: Harrison posterior tangent method are lines drawn contiguous with the posterior vertebral body margins used to quantify subluxation patterns (Courtesy: CBP seminars).*

The demonstration of paralleled spine alignment improvements with reductions in pain and disability, versus no change in untreated control groups in pre-post clinical trials have been performed [18–23]. The demonstration in randomized clinical trials that only patient groups achieving lordosis and sagittal posture improvement (lumbar or cervical) achieve long-term improvements in various outcome measures versus comparative treatment groups not getting spine alignment improvement who experience regression in multiple outcome measures at follow-up have also been done [24–35].

CBP technique is a full-spine posture and spine rehabilitation method that incorporates mirror image® (MI) exercises, adjustments, and traction applications in the restoration of normal/ideal spine alignment [1, 36–38]. Chiropractors and other manual therapists practicing CBP structural rehabilitation techniques have used this spine model as a structural goal of care for over 20 years. It is noted that this model serves as the baseline for generalized patient comparison, however, specific patient comparisons must include patient-specific considerations related to thoracic inlet parameters [39] as well as pelvic morphology [40] as these may dictate a structural modification to the sagittal plane model for a given patient [37]. There are software programs (i.e., PostureRay Inc., Trinity, FL, USA) that aid in the ability for practitioners to assess spine alignment quickly in daily practice (**Figure 4**).

Today the evidence supporting the CBP approach to the correction of cervical lordosis and lumbar lordosis is substantial. There are now many randomized controlled clinical trials (RCT) documenting the reduction of anterior head translation

### **Figure 4.**

*Three patients demonstrating dramatically different spine alignment patterns. Left: Excessive lumbar hyperlordosis, L4 anterolisthesis, and excessive anterior sagittal balance in a mid-aged female with disabling low back pain; Middle: Excessive thoracolumbar kyphosis and early degenerative changes in a mid-aged male; Right: Excessive thoracic hyperkyphosis in a young male with Scheuermann's disease. Red line is contiguous with posterior vertebral body margins; green line represents Harrison normal spinal model. (Courtesy: PAO).*

### *Restoration of Cervical and Lumbar Lordosis: CBP® Methods Overview DOI: http://dx.doi.org/10.5772/intechopen.90713*

[24, 28–35], as well as the increase in cervical lordosis [24, 28–35], and the increase in lumbar lordosis [25–27] in patients presenting with hypolordosis in each of these spinal areas. These trials have also demonstrated that the postural and spinal improvements are associated with improvements in various patient outcomes, including: pain, disability, quality of life, range of motion as well as specific physiological measures such as improved neurological central conduction times—the ability of the brain to communicate with the body.

We will now address in different sections the CBP approach to the restoration of cervical lordosis and then the restoration of lumbar lordosis.
