a. contraction to effect rotation of an innominate (e.g. iliacus; Fig. 2.46B,C) or sacral torsion (e.g. piriformis; Fig. 2.46A) as these muscles attempt to stabilize the SI joint(s) by bringing the surfaces closer together, decreasing joint mobility or causing actual ‘locking’

b. ‘facilitation’ of specific muscles occurring as part of the ‘malalignment syndrome’ itself (see ‘Asymmetry of muscle tension’ below).

Pain may also result from an increased or abnormal pressure on the malaligned, and hence incongruent, SI joint surfaces. Given the propeller-shape of this L-shaped joint, with the convex surface of one part of the ilium or sacrum fitting its concave counterpart, it is not hard to imagine how little displacement of one surface relative to the other is actually needed to result in stress on the joint (Fig. 2.3). Development of the convex iliac ridge and matching sacral concavity by the 3^RD decade (Fig. 2.7B), also subsequently of other seemingly matching depressions and elevations or just degenerate changes will only further increase the stress that results with even minimal displacement of these joint surfaces whenever pelvic malalignment recurs. Bone scans may actually show increased and/or asymmetrical activity in the SI joints (Fig. 4.39). In the absence of any indications of an inflammatory condition, such as a seronegative spondyloarthropathy or ankylosing spondylitis, these abnormalities on the bone scan may simply reflect an increase in bone turnover triggered by an increase in pressure on the joint surfaces. Unless there is an actual inflammatory element, the abnormalities on the bone scans usually disappear with time as the pressure on the surfaces is finally relieved by keeping the joint in alignment.

Following successful realignment of a previously ‘locked’ joint, examination may now reveal hypermobility of that joint which can predispose to a recurrence of the malalignment and the ‘locking’. The hypermobility may be indicative of ligament laxity, osteoarthritic joint degeneration, poor muscle support or control, or a combination of these. Ligament laxity may be the result of:

1. a previous severe sprain or strain of the ligaments, such as can occur with a shear injury to the SI joint sustained by falling and landing on one buttock or leg (Fig. 2.51B)

2. ligament lengthening that has occurred with time as the ligaments are:

a. put under constant tension and gradually stretched by the distortion of the pelvic ring caused by the malalignment (Figs 2.19, 2.21, 3.65)

b. repeatedly being submitted to quick stretches by some of the techniques used to correct the malalignment – especially high-velocity low-amplitude manipulations that make it difficult to judge the end-point and may result in repeated overstretching of the ligament – as compared to using a gentle low-velocity, high-amplitude manual therapy method, such as the muscle energy technique (see Chs 7,8).

3. generalized joint hypermobility, related to:

a. a genetically-determined defect in the amount or quality of elastic tissue produced; this problem can vary in degree of severity and, at its worst, presents in the form of conditions such as the Ehler–Danlos syndrome

b. an increase in relaxin hormone, sometimes as a result of a tumour but more commonly seen as a pregnancy progresses, usually from the 4^th month on, subsiding gradually during the weeks post-partum but tending to remain elevated until breast-feeding is discontinued (Marnach et al. 2003)

Fig. 3.65 Sacrospinous ligament origins and insertions on an anteroposterior view of pelvis. (A) Pelvis aligned: the distance between the right origin and insertion (light dots) is equal to that on the left (black dots). (B) ‘Rotational malalignment’ with ‘right innominate anterior, left posterior’ rotation: the origin and insertion are brought closer together on the right (light dots) and separated on the left (black dots). A similar change would occur with a ‘right outflare, left inflare’.

The presence of generalized hypermobility other than during pregnancy is important to establish because these patients generally do not respond as well to realignment attempts, tend to lose correction more easily and are more likely to benefit from additional measures to maintain correction (e.g. foot orthotics, SI belts and ligament strengthening injections). Generalized hypermobility is more common in the group that repeatedly ‘switches sides’ and changes patterns of malalignment; for example, presenting with ‘anterior’ or ‘posterior’ rotation, ‘upslip’ or ‘outflare/inflare’ on different sides and in different combinations from one examination to the next, sometimes within hours.

A quick test to assess the degree of mobility is to have the person flex the wrist and then passively bring the thumb toward the volar aspect of the forearm (Fig. 3.1). In most tests, the thumb will end up parallel to the forearm. If the thumb is further away from the forearm (e.g. the person on the left in Fig. 3.1A), or if it ends up close to or even touching the forearm, the person may well have generalized joint hypo- or hypermobility, respectively. This should be confirmed by doing a more complete assessment of the amount of joint play possible on passive movement of other joints; for example, the 9-point Beighton scale may be appropriate (Beighton et al. 1999; Fig. 3.1B). A side-to-side comparison is also important to make sure one is not just dealing with laxity attributable to previous injury of specific ligaments on that side.

Fig. 3.1 Test for degree of overall joint mobility. (A) Mobility is relatively decreased in the person on the left, whose thumb actually points away, compared with the person on the right, whose thumb ends up parallel to the forearm (the usual finding with normal mobility). (B) 9-point Beighton scale for hypermobility: passive finger dorsiflexion past 90 degress (R/L); passive thumb apposition to the flexor surface of the forearm (R/L); hyperextension of the R/L elbow, the R/L knee beyond 10 degrees; trunk flexion to rest the palms on the floor (with the knees extended).

(Courtesy of Beighton 1999.)

Variants of the syndrome seen with ‘rotational malalignment’

Malalignment of the pelvis, spine and extremities can result from a number of interacting causes. Postural distortion, for example, may result in a muscle imbalance but the distortion may itself be the result of such an imbalance. As Maffetone indicated in 1999, potentially more than one postural distortion can result from the same muscle imbalance. He gave the example of psoas major, indicating that inhibition of tension tone in this muscle on one side, for whatever reason, typically causes the pelvis to tilt. The pelvis usually rises on the opposite side, where psoas major is now in relative ‘overfacilitation’, the tension tone in the muscle being increased compared with that on the inhibited side (Fig. 3.2A). The effect would be to rotate the innominate anteriorly on the ‘facilitated’ side, raising the iliac crest. Maffetone, however, went on to say that:

… in many cases, the reverse is true and the psoas inhibition is found on the side of the elevated pelvis. This may depend on which problem was primary and which secondary, how the foot reacts, what other muscles are compensating, and other factors.

(Maffetone 1999: 88)

Fig. 3.2 Assessing static posture. (A) Psoas inhibition on the right may allow medial rotation of the ipsilateral foot with excess pronation. The lumbar spine is convex on the contralateral side (tight psoas). The pelvis may be lower (sometimes higher) on the ipsilateral side. (B) Right sartorius or gracilis inhibition may cause a posterior rotation of the pelvis, seen as an elevation of the ipsilateral side and genu valgum.

(Courtesy of Maffetone 1999.)

The reader is referred to works such as by Maffetone (1999) for a detailed discussion of the postural imbalances that can result with the ‘inhibition’ and ‘facilitation’ of various muscles.

This book will concentrate on two variants of the ‘malalignment syndrome’ seen in conjunction with particular patterns of ‘rotational malalignment’:

1. the ‘left anterior and locked” pattern (Fig. 3.3A)

Individuals affected present with the left leg rotated externally (outward, away from midline) and the right internally (inward, toward midline), with a pattern of weight-bearing tending to left pronation and right supination. This relatively rare pattern (accounting for approximately 5% or less in an orthopaedic medicine practice) is seen in association with a combination of factors that most consistently involves ‘anterior’ rotation and ‘outflare’ of the left innominate and ‘locking’ of the left SI joint. It will, therefore, be referred to as the ‘left anterior and locked’ pattern.

2. the ‘more common’ rotational patterns (Fig. 3.3B)

Individuals affected present with the right leg rotated externally and the left internally, while weight-bearing tends to right pronation and left supination. The patterns can be made up of any combination of ‘anterior’ or ‘posterior’ rotation of either the right or left innominate, and ‘locking’ of either the right or left SI joint (excluding the rare ‘left anterior and locked’ pattern, mentioned above). These variations will henceforth be referred to as the ‘more common’ patterns as they account for about 90-95% of those presenting with ‘rotational malalignment’.

Fig. 3.3 Two variants of the ‘rotational malalignment’ presentation (see also Figs 3.22, 3.23). (A) With the rare ‘left anterior and locked’ pattern – the left foot turned outward from the midline and pronating, the right in toward midline and supinating: (i) standing and (ii) walking view. (B) With one of the ‘more common’ patterns: the right foot is turned outward and pronating; the left inward (may even cross the midline) and supinating (see Fig. 3.19Bii).

The two variants of the ‘malalignment syndrome’ seen with the ‘left anterior and locked’ versus the other, ‘more common’, patterns of ‘rotational malalignment’ differ primarily from each other in terms of the associated pattern of:

1. asymmetry of joint ranges of motion

2. asymmetry of weight-bearing

3. asymmetry of muscle tension and strength

These differences will be highlighted in the discussion of the specific asymmetries.

Asymmetry of pelvic orientation in the coronal (frontal) plane

Pelvic obliquity is one of the most consistent findings seen with both ‘rotational malalignment’ and an ‘upslip’

As indicated in Chapter 2, ‘rotational malalignment’ results in a complete asymmetry of the major pelvic landmarks (Figs 2.42, 2.73A,B, 2.76), both side-to-side and front-to-back, because of an asymmetry of the sacrum and the innominates with:

Given the predominance of ‘right anterior’ innominate rotation, one is more likely to find elevation of the right than the left lateral iliac crest – approximately 80% versus 20%. One can, however, see the left crest elevated in conjunction with a ‘right anterior’ rotation. Which iliac crest is higher is determined not only by the direction of innominate rotation but also by factors such as:

1. the position in which the person is examined: with a ‘right anterior’ rotation, for example, the right iliac crest may be higher or lower in standing but will usually be higher in sitting and definitely in prone-lying; the most common pattern is shown in Figures 2.73C and 2.76B

2. a coexisting anatomical (true) leg length difference (Figs 2.72B, 2.74A), ‘upslip’ or ‘downslip’ (Fig. 2.73A,B)

3. the direction of a sacral torsion, if present (Figs 2.10, 2.14, 2.42, 2.88)

4. the side of SI joint ‘locking’, if present (Figs 2.119–2.121)

As an example of these variations, a person with ‘right anterior’ rotation may have elevation on the left iliac crest in standing because of a true LLD, left leg long. In sitting and in lying prone, however, the crest may now be elevated on the right side because the effect of the LLD has been removed. Alternatively, someone with no LLD but a ‘left anterior, right posterior’ rotational pattern often has elevation of the right iliac crest in standing and sitting but elevation of the crest on the left side when lying prone and the typical findings on the ‘sitting-lying’ test in keeping with the ‘left anterior’ rotation; i.e. ‘left leg lengthens lying, left landmarks (ASIS, pubic bone) lower’.

Clinical correlation: coronal (frontal) plane asymmetry

The difference in the elevation of the iliac crests is sometimes strikingly obvious and may be accentuated by the cut of a costume. The visual effect of this may distract from the aesthetic appearance. In disciplines such as dancing and figure-skating, this could conceivably affect the perception and judgement of style. In anyone, there may be mundane problems related to clothing, straps or belts repeatedly slipping down or even completely off on one side, just as objects carried over the ‘lower’ shoulder will tend to slip off (Figs 2.70, 2.76B, 2.90, 2.95A, 3.4).

Fig. 3.4 An ‘upslip’ and ‘rotational malalignment’ typically result in one shoulder being lower (e.g. as a result of a compensatory scoliosis). (A) Bag carried on left repeatedly slips off lowered left shoulder; running the strap over the right side solves that problem but calls on a number of musculoskeletal adjustments (note person leaning into the right side). (B) Straps across both shoulders, as with a backpack, distribute the weight more evenly, decrease the need for adjustments and help counter recurrences of malalignment.

Sitting is likely to present problems. The ischial tuberosities are at different levels: raised on the side of the ‘anterior’, lowered on the side of the ‘posterior’ rotation (Figs 2.76D, 6.4). With a ‘right anterior’ rotation, the right ischial tuberosity can easily end up 1 cm off the seating surface, the weight now borne primarily by the left tuberosity. The person often talks of ‘sitting more on one buttock than the other’ or ‘off to one side’ and may get relief simply by putting a hand, small pillow or a magazine under the raised tuberosity to fill the gap when riding (see Ch. 6), driving, flying, or travelling by other means, or in any other situation where they are sitting for a longer period of time.

Sitting increases the pressure on the lower tuberosity and creates a shearing force on the ipsilateral SI joint by pushing the innominate upward relative to the sacrum. In addition, the ischial tuberosities serve as the insertion of the sacrotuberous ligament and the origin of the hamstrings (Figs 2.5, 2.6, 2.21). These structures are more vulnerable to direct pressure at this site on the side of the ‘posterior’ rotation, especially when sitting in a slouched position or on a hard surface. Slouching or sitting in a bucket seat allows the pelvic ring – the innominates and sacrum – to tilt posteriorly as a unit, further increasing pressure, especially on the ischial tuberosity and the PSIS on the side of the posteriorly rotated innominate. Aside from using a hand, cushion or magazine between the raised ischial tuberosity and the seat to actually fill in the gap created by the ‘anterior’ rotation, the person may have found that he or she gets comfort by:

1. increasing the general amount of cushioning under both buttocks, allowing the lower one to sink in further than the higher one – memory foam is ideal for this (Fig. 7.42)

2. placing a cushion under the thighs, ahead of the ischial tuberosities; better still, a pillow that is tapered down from buttocks to thighs (which also shifts weight-bearing forward, more under the thighs)

3. continuously shifting weight-bearing from side-to-side to off-load the tender ischial tuberosity

None of these methods may work very well, especially when the person has to remain seated for a longer period of time in a confined space or when the seating area is small and hard, such as a church pew, a rowing shell or a bicycle seat. In riding, a lowered left ischial tuberosity may increase pressure on the horse’s left paravertebral musculature, by digging into the muscles directly (bareback) or through the saddle (Fig. 6.4A). The increased pressure can cause a reflex increase in tension in these muscles so that the horse starts to appear ‘stiff’ on that side, hesitating or eventually even refusing to veer to the right on command (see Ch. 6).

Given all these situations in which the iliac crest is higher or lower, often changing from one position to another, it is important not to lose sight of the overall picture and realize that these variations in height call for tests which are more definitive and consideration of a differential diagnosis that, at this point, includes ‘rotational malalignment’ or an ‘upslip’, an anatomical (true) or a ‘functional’ LLD.

Asymmetry of pelvic orientation and movement around the vertical axis in the transverse plane

With ‘rotational malalignment’, the pelvic unit often appears rotated counterclockwise, around the vertical axis in the transverse plane some 5–10 degrees, rarely more. This probably relates to the fact that ‘right anterior, left posterior’ rotation, which tends to twist the pelvic ring in a counterclockwise direction and brings the right ASIS forward and the left backward, is by far the most frequently noted pattern. Therefore, the pelvis is more likely to jut out a bit at the front on the right side and recede on the left when the person is standing (Fig. 3.5A). Rotation in this plane will, however, also be influenced by the position of examination. Consider the example of the person who has such seemingly obvious right forward rotation in standing. When he or she goes to lie prone on a hard plinth, the protruding right ASIS will be the first to contact the plinth and will be forced posteriorly. In this position, therefore, the pelvis could now look level, or the right PSIS may even end up protruding backward compared to the left, as if the pelvis had rotated clockwise in the transverse plane.

Fig. 3.5 Asymmetry of pelvic rotation around the vertical axis in the transverse plane typically seen with ‘rotational malalignment’. (A) Passive: standing – asymmetry, usually with some counterclockwise rotation of the pelvis (left side positioned relatively backward, right forward on a superior view); the trunk may rotate in the opposite or the same direction, with compensatory rotation of the head and neck to keep them in midline (not shown). (B) Active clockwise rotation to 40 degrees. (C) Active counterclockwise rotation decreased to 30 degrees (note the decreased facial, shoulder girdle and chest profile compared with Fig. 3.5B).

In the presence of ‘rotational malalignment’, active and passive rotation of the pelvis in the transverse plane is usually restricted into the side of the posteriorly rotated innominate.

Restriction into the side of the ‘posterior’ rotation can occur for the following reasons:

First, counterclockwise rotation of the pelvis in the transverse plane seen normally during the walking cycle – right ASIS forward with right ‘swing’ leg – occurs with the simultaneous contrary rotation of the innominates: right posterior and left anterior (Figs 2.12, 2.21, 2.22, 2.41). The pattern is reversed with clockwise rotation on swinging the left leg forward.

Second, when there is ‘rotational malalignment’ with the right innominate seemingly held in ‘anterior’, and the left in ‘posterior’ rotation, clockwise rotation is increased in part due to the fact that the malaligned innominates can rotate further from their resting position in the directions needed to allow this particular movement (Fig. 3.5B). The left one, which starts off rotated posteriorly, can rotate anteriorly through more degrees until it reaches the end of available range in the sagittal plane than if it had started from its normal position. Similarly, the anteriorly rotated right innominate can rotate posteriorly through more degrees until it reaches the end point in that direction. Also, on account of the wedging of the sacrum, the left innominate already flares slightly inward, the right outward. Overall, this translates into more degrees of clockwise rotation.

Conversely, counterclockwise rotation is limited by the fact that the innominates are already rotated part way into the directions required for them to move into for this manoeuvre (Fig. 3.5C). Namely, the right is already rotated anteriorly and the left posteriorly, restricting further movement into these directions required for counterclockwise rotation.

To assess rotation around the vertical axis in the transverse plane, ask the person to stand with the inside of the legs or feet just touching. Sit behind, your feet resting against the outside of his or her feet and, with your knees and calves gently press the lower part of the person’s legs together in order to minimize any rotation that might otherwise occur through the lower extremities. With the arms crossed on the chest, he or she should let the trunk, head, neck and upper extremities move with the pelvis as one unit to end point, first to right and then to left. Note and compare the amount of rotation possible from neutral. There is often the feeling of a sudden, hard stop to rotation of the pelvis into the side of the restriction, which the person may well sense.

A rotation of 40 degrees to the right and only 30 degrees to the left would, for example, not be unusual in someone with ‘rotational malalignment’ with ‘right anterior/left posterior’ innominate rotation (Fig. 3.5B,C). Discrepancies of greater magnitude can occur, the degree of limitation appearing to be proportionate to the degree of difference in ‘anterior’ versus ‘posterior’ innominate rotation. However, correction of the malalignment immediately removes this restriction and may now allow for an equal amount of rotation: 40 degrees to right and left, in the example given. The fact that rotation might actually now be 45–50 degrees or even more bilaterally suggests that other restrictive factors were operative prior to realignment, such as restriction caused by sacral torsion and/or rotation, asymmetry of muscle tension, and asymmetry of the hip ranges of motion (see below).

Clinical correlation: transverse plane asymmetry

This asymmetry interferes with the ability to execute turning manoeuvres that require pelvic rotation in the transverse plane when both feet are on the ground. The prime example is downhill skiing, in which turns are initiated in large part by movement of the pelvis in this plane, combined with shifting weight onto the appropriate edges. The skier is more likely to experience limitation on attempting a turn into the side of a posterior innominate rotation (see Ch. 5).

Forced active or passive rotation on the pelvis into the side of the limitation is more likely to lead to soft tissue or even bony injury because the physiological and anatomical barriers will now be exceeded earlier.

The anatomical barrier defines the terminal range of joint motion; movement past that point results in disruption of tissue. The person (e.g. workman, skier or wrestler) presenting with malalignment is, therefore, at increased risk of injury whenever an opponent, a change in direction, or a collision forces the pelvis into that restriction.

Rotation of the spine occurs primarily through the thoracic segment. Whenever rotation of the thoracic segment is impaired, rotational stresses on the lumbar spine and the pelvic region are increased, making them even more vulnerable to injury if forced actively or passively into the direction of a restriction already caused by the malalignment. This can occur, for example, whenever:

1. the thorax is pinned to the floor, such as in wrestling (Fig. 5.36)

2. a gymnast restricts thoracic rotation by holding on to the apparatus with both hands while spinning or twisting the pelvis and legs (Fig. 5.11B,D).

Conversely, a restriction of rotation of the pelvic unit in one direction at the pelvic level may require a compensatory increase in the amount of rotation of the thoracic spine. Such an increased demand on the thoracic segment is more likely with activities that normally require a simultaneous rotation of both the pelvis and trunk while standing upright: with certain field events (discus, hammer, shot and javelin), on playing golf, baseball, and court sports, or simply reaching to the right or left (Fig. 2.44). The increased stress placed especially on the thoracolumbar (T/L) junction may account for the onset or aggravation of mid back pain, especially if these actions are a part of the person’s work or sports activities. This issue is discussed further under ‘Curvatures of the lumbar, thoracic and cervical segments’ (see below).

Asymmetry of sacroiliac joint mobility

Those presenting with ‘right’ or ‘left anterior’ rotation show SI joint mobility dysfunction, which may take any of the forms shown in Box 3.2.

Box 3.2 Sacroiliac joint movement dysfunction

1. ‘Locking’: jamming of the innominate and sacrum against each other on one side, (e.g. excessive ‘anterior’ rotation of an innominate) can result in a loss of movement between the two, so that they now move together instead; on the affected side, this results in:

a. excessive upward and downward movement of the PSIS on trunk flexion and extension, respectively (Figs 2.119, 2.120)

b. a failure of the landmarks to separate on the ‘kinetic rotational’ or Gillet test (Fig. 2.125)

c. no movement being discernible on SI joint ‘spring’ stress tests ( Figs 2.110–2.112)

2. Partial ‘locking’, which results in:

a. some upward and downward movement of the PSIS relative to the sacrum on trunk flexion and extension, respectively, and the kinetic rotational and stress tests, but less than what occurs on comparison to the normal side

3. ‘hypermobility’ or ‘laxity’:

a. defined as excessive movement around one or more axis and/or in the anteroposterior, craniocaudal or medial-lateral transverse plane(s) (Figs. 2.114, 2.115)

b. detectable uni- or bilaterally on the stress tests

Hypomobility or outright ‘locking’ may be caused by excessive rotation of an innominate relative to the sacrum, a reflex increase in muscle tone or a combination of these.

The person who had ‘rotational malalignment’ with ‘locking’ or decreased mobility of one SI joint on initial examination may present for reassessment with the malalignment still evident even after having undergone a course of manual therapy treatments. At this time, possible findings include the following:

1. the previously noted hypomobility or actual ‘locking’ may still be detectable on the same side; also, sometimes these problems may actually have ‘switched’ sides

2. more likely than not, movement on lumbosacral flexion, extension and kinetic rotational tests will now be found to be normal (i.e., ‘locking’ resolved)

3. the side previously felt to be hypomobile may now turn out to be hypermobile, suggesting a possible underlying problem of ligament laxity, joint osteoarthritis, muscle weakness, impaired control or a combination of these that was previously hidden by the ‘locking’.

Achieving correction of the ‘rotational malalignment’ usually re-establishes normal movement on flexion/extension and kinetic rotational tests, and may serve to expose an underlying problem of hypermobility.

Curvature of the lumbar, thoracic and cervical segments

What follows is an abbreviated discussion of how the resting curves of the spine are influenced by:

1. side-flexion of the spine and/or rotation of the pelvis and spine

2. malalignment of the pelvis and excessive rotation of individual vertebra(e) or a vertebral segment.

The interested reader is referred to extensive discussions of this aspect by Lovett 1903; Fryette 1954; Gracovetsky and Farfan 1986; Richard 1986; D Lee 1992b, 2004a, 2011).

In 1903, Lovett pointed out that:

1. the spine is a flexible rod that is already bent in one plane (sagittal) to create the lumbar lordosis and thoracic kyphosis

2. the rod, therefore, cannot be bent in another plane (e.g. coronal or ‘frontal’) without twisting at the same time.

Therefore, in the absence of congenital or traumatic abnormalities of the vertebrae (e.g. hemivertebrae or stress fractures), the lateral curves of the spine are formed by rotation of the vertebrae of a respective segment: the lumbar, thoracic and cervical.

This feature was explored further by Gracovetsky and Farfan (1986). They reported that when one tries to superimpose a lateral curve on the pre-existing lumbar lordosis and thoracic kyphosis, the following occur:

First, the components of the lumbar spine are twisted. For example, on side-bending the trunk to the left, the bodies of vertebrae L1–L4 inclusive rotate to the right, into the convexity formed. Their spinous processes, therefore, rotate to the left, toward the concavity formed (Figs 2.42, 2.96, 3.6, 4.6, 4.24). This rotation is accompanied by simultaneous side-flexion of the vertebrae into the concave side, as well as either extension or forward flexion; that is, as discussed in Ch. 2, there is movement in all three planes (Figs 2.42, 2.52B, 2.94, 2.96).

The combination of Forward flexion, Side-flexion and Rotation constitutes the so-called ‘FSR movement’; should extension occur, the result would be an ‘ESR movement’. These patterns are delineated by the so-called ‘laws’ of Fryette (1954). A vertebra may become excessively rotated to the right or left and/or into extension or flexion, and become ‘stuck’ in that position. Movement in one facet joint will then be pathologically restricted, causing the vertebra to rotate around that facet on flexion or extension (Figs 2.52B, 2.94A).

In other words, the overall effect is normally ‘a locking one and so plays a safety role. Where the physiological limit has been exceeded, to reverse this mechanism will be the key to the treatment of one part of the lower back syndrome’ (Richard 1986).

Second, it is harder to predict the direction of vertebral rotation in the thoracic segment, which is affected by the attaching ribs, the overlying scapulae and soft tissue attachments. The clear-cut correlation that exists in the lumbar segment is missing. The central thoracic vertebrae are more likely to rotate into the convexity (Fig. 3.6); the upper ones are less likely to do so (Lee 1992b).

Fig. 3.6 Changes that occur normally in the vertebrae and sacrum on left side-bending: right rotation, forward flexion and left side-flexion.

Third, during normal gait, there is a continuous change in the convex/concave curve patterns seen in the thoracic and lumbar spine, changing in direction on right and left swing-through to weight-bearing back into swing-through phase of the cycle while the pelvis and thorax rotate in opposite directions in the transverse plane, balanced by contrary movement of the arms (Fig. 2.41). During normal gait, therefore, there is a matched rotation of the pelvis and spine which helps to balance body weight while the head remains centred throughout.

Effect of malalignment on the spine

Someone who is in alignment and has equal leg length may have a straight spine but, more likely, some minor ‘intrinsic curves’ when standing. ‘Rotational malalignment’ results in a pelvic obliquity attributable both to the rotation around the sagittal axis and to the shift of the iliac crests: up on the side of the ‘anterior’ and down on the side of the ‘posterior’ innominate rotation. Assuming a pelvic obliquity, right side up and left down: if the spine remained straight and perpendicular to the pelvis, the head would end up off-centre, leaning to the left, something that would disturb the visual and balancing mechanisms. A person usually will automatically form compensatory lateral curves of the spine so that the head ends up in centre, vertical and with the right and left eyes and ears level. Unfortunately, the compensatory curves can exacerbate any ‘intrinsic curves’. Also, as indicated above:

1. The spine cannot accommodate without simultaneous rotation of the vertebrae in the thoracic and lumbar segments.

2. The curve formed in the thoracic segment is usually opposite in direction to that formed by the lumbar vertebrae, resulting in the typical double curve, or ‘scoliosis’ (Figs 3.7A, 3.8, 2.70, 2.90, 2.91, 2.95, 2.120C).

3. The lumbar and central thoracic vertebral bodies appear to rotate into the respective convexity of these curves (Fig. 3.6).

4. X-Rays will show this typical double, ‘scoliotic’ curve, with a reversal at the thoracolumbar junction (Figs 4.6, 4.31) and possibly also noticeable aggravation of any ‘intrinsic’ curves on comparison to X-rays taken when the person is in alignment.

Fig. 3.7 Typical patterns of scoliosis (standing). (A) Patterns seen with ‘rotational malalignment’ and associated pelvic obliquity (inclined to the right side in the majority). (B) Scoliotic curves commonly seen with right and left anatomical (true) leg length difference.

Fig. 3.8 Common patterns relating pelvic obliquity and scoliotic curves to the presentation of ‘rotational malalignment’. (A) ‘Right anterior, right locked’. (B) ‘Left anterior, left locked’. (C) ‘Right anterior, left locked’. NB: in (B), right pelvic crest is raised in standing and sitting, the left up in prone-lying; (C) shows a reversal of the scoliotic curves sometimes seen on moving from standing or sitting to prone-lying.

If the cervical spine simply continued in the trajectory of the thoracic curve, the person would be walking about with the head and neck still half-cocked, leaning toward the side of the thoracic concavity! Among other things, this would continue to upset the balancing mechanism, which is dependent on visual and vestibular input and also, in large part, on proprioceptive signals arising from the muscles and joints in the neck region and the rest of the body. The brain could have difficulty dealing with the additional sensory input generated when the head and neck are set at an angle.

There is, therefore, a further reversal in the curvature of the spine in order that the head will, hopefully, end up straight and in midline. This reversal usually occurs at the level of the cervicothoracic junction (Fig. 2.91A). It may, however, start as far down as T4 or T5, which accounts for a large number of those people with a very obvious curvature of the lower and mid-thoracic segment convex, for example, to the right yet with the shoulder and scapula dipped down on the right side instead of the left, as might be expected (Fig. 2.91B). Reversal occurring in the upper thoracic region creates another stress point and may account for reports of interscapular and upper back discomfort. Also, there is likely to be a constant increase in tension or outright contraction in muscles attempting to straighten the cervical spine and avoid any rotation of the head and neck.

The direction of the curves associated with ‘rotational malalignment’ (or an ‘upslip’) may differ depending on whether the person is examined standing, sitting or lying prone. The curves are probably best regarded as an adaptation of the spine to the interaction of several factors, including the direction of sacral torsion, the pelvic obliquity, the lateralization of ‘anterior’ and/or ‘posterior’ innominate rotation and SI joint ‘locking’, and the presence of any lengthening having occurred with prolonged stretching, or increased tension or actual contracture of soft tissue attaching to the pelvis, ribs and spine. More important than defining the direction of these curves is to determine if there are any factors that may have resulted in formation of the curves, including malalignment of the pelvis or rotation of individual vertebrae, that can be treated using manual therapy (see Ch. 7).

When the person is lying prone or supine, there is also the passive torquing of the pelvis and/or thorax that results from the plinth pushing upward on any bony point that has been rotated forward or backward (e.g. shoulder, ASIS or PSIS). If we assume that a person presents with 5–10 degrees of forward rotation of the pelvis on the right side, and a contrary rotation of the trunk so that the left shoulder ends up forward: on lying prone, the contact of these protruding points with the surface results in a force that torques the pelvis clockwise and the thorax counter-clockwise. This may account for a reversal of the curves sometimes evident in prone-lying compared with those seen in standing and sitting.

When one looks at the combination of pelvic obliquity and the pattern of the thoracic and lumbar curves, the pattern is least likely to change from standing to sitting to lying prone if the anterior innominate rotation and ‘locking’ are both on the right side (Fig. 3.8A). With the ‘left anterior and locked’ pattern, the obliquity will change from the right side usually being higher in standing and sitting, to the left being higher when lying prone; whereas the curves may remain the same or change on going from one position to another (Fig. 3.8B). When the ‘anterior’ rotation is on one side and the ‘locking’ on the other, the curves are likely to change on lying prone; whereas the pelvic obliquity may stay the same, but this is not predictable (Fig. 3.8C).

Interestingly, the curves associated with an anatomical LLD in standing appear to be no less predictable than those associated with ‘rotational malalignment’. That is, one may find a lumbar convexity into either the side of the long or short leg. This is in keeping with the literature, which suggests that the curve formed by the lumbar spine is usually convex to the long-leg side, but also warns of frequent exceptions.

However, as stated before, more important than determining the actual thoracic and lumbar curves in the various positions is to determine what is the reason for the curves – idiopathic scoliosis, LLD, malalignment, or some other underlying cause? – to help decide if and what treatment is indicated.

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