The general findings on examination at an affected level have been described in Ch. 2. Rotational displacement can affect any vertebra between the occiput and the sacrum but it does involve certain levels of the spine with increased frequency (see Ch. 3). Note is here made of some of these levels.

L4, L5 or both vertebrae

Though these are involved infrequently (affecting some 5% of those with recurrent pelvic malalignment), there are three major problems that can result with rotational displacement at these levels: pain, restriction of range of motion and secondary malalignment of the sacrum and the SI joints (Figs 2.52, 2.96). Instability of the lumbosacral area may be caused by the initial injury or develop subsequently with the stress arising from recurring vertebral rotational displacement.

Pain

Usually pain is severe and of acute onset, coincident with the displacement of one or both vertebra. It may be localized to the low back region but there may also be radiation to the buttocks or even referral to the lower extremities as a result of:

1. increased tension on soft tissue structures

– involves primarily the paravertebral muscles, interspinous, supraspinous and other intervertebral ligaments and, at the L4/5 level, also the iliolumbar ligaments (Figs 2.4, 2.5, 2.52, 3.61B, 3.68, 7.40)

2. stresses on facet joints

a. compression on the side contralateral to the direction of vertebral rotation, and

b. distraction (opening) ipsilaterally (e.g. clockwise trunk rotation results in approximation of the left and separation of the right joint surfaces; Fig. 2.52B)

3. torquing of the annulus and the disc

Clockwise rotation of L5, for example, increases tension in the right iliolumbar as well as the supra- and interspinous ligaments, also multifidi and rotatores muscles, primarily from the L3 to S1 level (Figs 2.29, 2.52B, 3.68). It compresses the left and separates the right L5–S1 facet surfaces. Distraction or entrapment of the facet joint capsule, ligaments and the nerve fibres supplying these joints can account for localized pain and referred symptoms to the ipsilateral buttock and lower extremity as far down as the ankle (McCall et al. 1979; Mooney & Robertson 1976; Travell & Simons 1992).

Restriction of range of motion

Vertebral rotational displacement is usually multidirectional, involving not only rotation in the transverse plane but a combination of either forward flexion (F) or extension (E), the rotation (R) around the vertical axis and side-flexion (S): the ‘FRS’ or ‘ERS’ presentation, respectively.

The ‘FRS’ and ‘ERS’ patterns result in a restriction of further movement into the directions indicated. L1–L4, for example, would normally rotate into a convexity; therefore, rotation would be counterclockwise into a left (Figs 2.42, 4.6, 4.26, 4.33) and clockwise into a right convexity (Fig. 2.96A). Superimposing a clockwise rotational displacement of L4 on a pre-existing right convexity will accentuate the already existing forward flexion (or extension), rotation and right side-flexion, limiting any further movement of L4 into all of these directions. Counterclockwise displacement of L4 would limit further movement into the opposite directions (Fig. 2.96B).

1. Assuming that the lumbar spine is forward flexed and L1-L4 have rotated clockwise into a right lumbar convexity (Fig. 2.96A):

– L1-4 would be in an FRS (forward flexed, right rotated, left side-flexed) position and further movement into these directions would be limited

2. if L4 now rotated to the left, its range of rotation into the opposite (left) FRS directions may be slightly increased

3. if L4 rotated even further to the right with an excessive force, it could be literally ‘jammed’ into a right FRS position.

Malalignment of the SI joints

A clockwise rotation of L4 or L5 exerts a rotational force on the innominates (anterior on the left and posterior on the right) because the simultaneous rotation of the transverse process – forward on the left, backward on the right – displaces the iliolumbar ligament origins away from their insertions and increases tension in these ligaments on both sides (Fig. 2.52A). There is also the torsional effect on the sacrum transmitted through the compressed left facet joint (Fig. 2.52B) and the L5-S1 disc. Reactive spasm in the adjacent quadratus lumborum and psoas can cause a recurrent ipsilateral ‘upslip’ (Fig. 2.62). Always remember that in the case of recurrent ‘rotational malalignment’ or an ‘upslip’, two common causes to consider (especially when there is excessive pain, usually acute in onset) are:

1. a failure to correct L4 and/or L5 vertebral rotational displacement, and

2. an actual instability of L4/L5, L5/S1, or both levels.

Thoracolumbar junction: T11, T12 and L1

Degenerative changes at the thoracolumbar junction are common in sports that call for repeated high spinal loading, high-velocity hyperflexion and hyperextension, and rotary motion (d’Hemecourt & Micheli 1997); in particular, gymnastics, ballet, wrestling, diving, waterski-jumping, and the bowling action of cricket, with gymnastics consistently receiving most mention (Kesson & Atkins 1999).

Rotational displacement at this junction typically involves T12 and/or L1, less often T11. These vertebrae may be involved in isolation or in combination; for example, the commonly noted ‘T12 right and L1 left’ rotation. In addition to the increased stress on facet joints, discs and ligaments, often with reactive muscle spasm localizing to the thoracolumbar region, rotational displacement at these levels may be complicated by the presence of an ‘upslip’ and/or ‘rotational malalignment’ of the pelvis, with:

1. pelvic obliquity and the compensatory scoliosis that creates stress points at the sites of reversal: the lumbosacral, thoracolumbar and cervicothoracic junctions

2. ‘facilitation’ of the left quadratus lumborum muscle; this increase in tension would act directly on the upper origins of this muscle from the L1 transverse process and may help explain the frequently seen L1 left vertebral rotation

3. ‘thoracolumbar syndrome’ (see Ch. 4; Figs 4.20–4.23)

4. rotational stresses on the attaching rib(s) and thoracic diaphragm

A rotational displacement of T11 and/or T12 results in increased stress on their costovertebral and costotransverse articulations. The associated torquing increases the stress on the anterior articulation of the 11th rib at the costochondral junction and its continuation as the costal cartilage. Pain can usually be provoked by applying pressure anywhere along the affected rib(s), and localized by direct pressure on the tender anterior and/or posterior articulation(s). Torsion of the lower ribs can also present as discomfort and even spasm of the attaching diaphragm. Any of these structures may become symptomatic, sometimes presenting as ‘chest’ or ‘abdominal’ pain and leading to extensive investigations to rule out a cardiac, respiratory or gastrointestinal problem (see Ch 4).

The T4 and T5 level

A rotational displacement of one or both vertebrae at these levels is a frequent occurrence and may reflect the fact that:

1. reversal of the curvature of the thoracic segment, which helps to ensure that the head ends up in the midline, may start as low as T4 or T5 (Fig. 2.91B)

2. forces normally associated with upper extremity activities intersect at this level; unopposed or unequal forces predispose to displacement of one or both vertebrae through muscle action (e.g. different muscles on opposite sides that can created a torsional component when acting together; unopposed unilateral rhomboid action because of weakness of its partner or a difference in tone, with ‘facilitation’ on one side and ‘inhibition’ on the other):

a. asymmetrical throwing; e.g. bowling, curling or track and field events that involve throwing an object with one arm (Figs 3.18, 3.51)

b. lifting a weight with one arm at a time

c. asymmetrical resisted manoeuvres; e.g. canoeing (Fig. 5.1)

d. sudden rotational forces on the trunk, especially when the pelvis is fixed, as in sitting or lying; e.g. collisions with players and objects; wrestling (Fig. 5.35).

Fig. 5.1 Canoeing in the kneeling, half-squatting position: torquing through the trunk, pelvis and even legs to carry out a ‘stern pry and bow cross-draw’ manoeuvre.

(Courtesy of Harrison 1981.)

Fig. 5.35 Wrestling action in which the trunk may be forcefully rotated (actively or passively) relative to a ‘fixed’ pelvis. (A) Forming a bridge (black shorts) to prevent a fall, with the pelvis ‘fixed’ by keeping both feet anchored to the ground. (B) The opponent (white top) is rotating the trunk clockwise while pinning the pelvis down on the floor.

The spinous processes will deviate from the midline in a direction opposite to that of the vertebral body rotation. As a result, the otherwise uniform curve formed by the thoracic spinous processes, convex to right or left, will be interrupted at the level of the deviated spinous process.

The associated pain is commonly felt in the interscapular area and/or under one or both scapulae. Pain from these sites can also be referred directly through the thorax to the anterior chest region, simulating angina (see Ch. 4). Other referred pain patterns to the shoulder girdles were discussed in Ch. 2 (Figs 3.12, 4.8). The athlete may localize the discomfort mainly to an area of increased tension and tenderness, or actual localized spasm. These changes may be palpable within the immediately adjacent rhomboid, mid-trapezius and paravertebral musculature (sometimes just on one side), or more laterally (e.g. subscapularis, infraspinatus, teres minor). The abnormal tension may simply reflect an increase in distance between the origin and insertion of these muscles. For example, a right deviation of the T4 spinous process, away from the left scapula, will increase tension in the attaching left rhomboid and mid-trapezius muscles. Alternately, the vertebral rotation may be secondary to an increase in tension with spasm, sprain or other injury affecting right rhomboid, pulling T4 to the right. Pain from T4/T5 can also trigger a reflex contraction of adjacent muscles in an attempt to splint this site. One is usually looking at a combination of factors (see Ch. 3). The area may, however, remain asymptomatic. Just as an imbalance in muscle tension can cause rotation of a vertebra in the interscapular region, specific muscles can be harnessed to rotate that vertebra back in line (see Ch. 7: ‘using rhomboid to effect realignment of T3’; Fig. 2.97).

On examination, pain may be evoked with posterior-to-anterior and/or rotatory pressure to the spinous process of the vertebra, possibly also to the one above and below. There may be discomfort with pressure applied to the soft tissues within the immediate vicinity. As in tests carried out for thoracolumbar syndrome, the findings may suggest an irritation of specific facet joints (Fig. 4.20). Trigger points are common in the muscles and ligaments at these levels and the adjacent posterior shoulder girdle regions. In addition, upper extremity ranges of motion may be restricted if they exert a rotational force on a tight, affected segment of the thoracic spine and provoke pain.

The ‘T3’ or ‘T4’ syndrome

As initially described by Maitland (1977), this refers to a symptom complex caused by the rotation of one or more vertebrae between T2 and T7, with T3 or T4 being most commonly involved. The symptoms are vague and widespread, with a report of pain and paraesthesias in the upper limbs and/or head pain (initially described as a dull aching or pressure feeling in an ‘all-over’ distribution). Symptoms may occur as a result of referral through the autonomic nervous system, originating from the upper thoracic region. In the series of 90 patients with T4 syndrome published by McGuckin in 1986, all had involvement of the upper extremity, either uni- or bilaterally, with a glove-like distribution of paraesthesias: fingers up to the wrist(s), or to the forearm, elbow or an even more proximal level (Fig. 4.9).

Fraser (1993) described a ‘T3 syndrome’ following trauma (e.g. a fall onto the shoulder or direct trauma to the anterior rib region). Symptoms may include paraesthesias, pain, vasomotor changes, a loss of sensation, the swelling of an extremity, anterior chest wall and/or axillary pain, a weakness of grip and difficulty breathing. The dramatic results achieved with manipulation to restore joint play at T3, the T3 costotransverse junction and sometimes also T2 and T4 led Fraser to propose that:

1. the correction ‘affects the vaso-motor system probably via the sympathetic ganglion at T-2’ (1993: 5)

2. it may be worth considering injection of local anaesthetic into this ganglion.

Examination and diagnostic techniques

Palpation of the paraspinal muscles in the vicinity of the displaced vertebra(e) may reveal tenderness and increased tension, or even muscle that has become hard and unyielding with recurrent spasm and now feels like a piece of rope running alongside the spinous processes on one or both sides. Chronicity of the problem can result in an increase in fibrous content, with the feeling of crepitus on palpation. The facet joints can be stressed:

1. non-specifically on side-flexion, back extension alone, and back extension combined with rotation to the right or left

2. more specifically, by applying a translatory rotational (Fig. 4.20A) or direct forces to individual spinous processes (Figs 4.20B, 5.2).

Fig. 5.2 Posteroanterior compression of individual spinous processes using the heel of the hand (pisiform bone).

In the case of vertebral rotational displacement, applying a further rotational force will reveal a restriction into the direction of the displacement and may provoke pain.

Posteroanterior translation or ‘glide’ in the sagittal plane may be similarly decreased or abolished, making the affected level(s) feel ‘stiff’ and unyielding. These changes are usually most easily appreciated in the region of T12–L1, where the reversal of the lumbar and thoracic curves in the sagittal and coronal planes itself already results in a restriction of joint play, even in the absence of any superimposed rotational displacement of one or both vertebrae (Fig. 3.14C). The levels adjacent to a site of such excessive rotation sometimes also lack ‘give’ and feel stiff; whereas hypermobility may be evident at sites immediately adjacent or some distance away, where the spine is attempting to compensate for this restriction of movement or has been stressed to the point that actual ligament laxity or joint degeneration has occurred.

Rib involvement can be assessed by examination for side-to-side asymmetry and by stressing the anterior and posterior rib attachments, either directly or by selectively springing the individual ribs along their length (Figs 2.93, 2.94). Diagnostic nerve root blocks can be helpful if involvement of posterior root or intercostal nerve fibres is suspected. Selective blocks of the rib articulations – costochondral, costotransverse and costovertebral – may also help to localize the origin of the pain (see Chs 3, 4, 7 and Figs 3.15, 3.16).

Limitation of sports performance by the common presentations of malalignment

The changes associated with the three common presentations of pelvic malalignment may limit sports performance by:

1. interfering with the desired or required range of motion

a. limiting range in a direction specifically needed for a certain sport (e.g. reaching outward and back to catch a ball; trunk rotation in kayaking, golfing; Figs 3.5, 3.49)

b. limiting combined trunk, pelvic and limb ranges of motion, which could create problems especially in those sports which require all parts of the body to be able to move through a full range of motion at any time, sometimes at high speed (e.g. court sports, lacrosse, white water kayaking)

2. provoking discomfort or pain

3. causing problems with muscle weakness and fatigue

4. altering weight-bearing, balance and controlled progression (ice skating, dancing/ballet)

5. disturbing symmetry, posture and style (synchronized swimming, competitive weight-lifting).

Appendix 10 notes the changes that can occur and some of the sports affected as a result.

Clinical correlations: specific sports

Specific sports create specific demands, and malalignment can affect the ability to meet these demands, often in a predictable manner. We are sometimes too quick to blame hand and foot preference, muscle tightness or weakness in an attempt to explain why one athlete is unable to change his or her style and repeatedly carries out a manoeuvre in the same way, or why another athlete has suffered a specific injury (especially if it is recurrent). A knowledge of the biomechanical changes and limitations imposed by the malalignment may allow for a more rational explanation. Appendix 11 details the clinical correlations related to some specific sports and Appendix 5 lists those specific to running.

Court, racquet and stick sports

A specific sport may appear to have been singled out as carrying an increased risk for a certain type of injury but the injuries outlined below are common to a number of these sports, and the mechanisms of injury often similar. Malalignment may well be a unifying factor.

Excessive rotation into a pelvic or thoracic restriction

Typical here is the rotation of the trunk required in tennis or golf (see below). Take the example of a ‘right anterior, left posterior’ innominate rotation and a lumbar segment convex to left (Fig. 2.42). When he or she attempts a right backhand with both feet fixed to the ground (Fig. 5.3), the initial left rotation is restricted:

1. through the lumbar segment, by the fact that the vertebrae have already rotated partly to the left, into the convexity (Fig. 2.42)

2. through the pelvic unit around the vertical axis in the transverse plane (Fig. 3.5C)

3. through the legs, especially by a limitation of further left internal, right external rotation, as these are already partially rotated in these directions

Fig. 5.3 A right backhand in tennis: the feet are relatively fixed to the ground and the trunk is rotated counterclockwise in preparation for hitting the oncoming ball.

(Courtesy of Schwartz & Dazet 1998.)

The combined effect is to restrict rotation through the lumbar spine and below. The rotational component has to occur, in large part, through the thoracolumbar junction and thoracic spine. Reaching backward in preparation for the backhand further increases the possibility of causing an injury to any one of these regions. This manoeuvre, which requires a counterclockwise rotation, again occurs primarily through the trunk when the feet are fixed. The player may be able to compensate by increasing rotation through the knees but is at increased risk of suffering an acute knee injury and acceleration of wear and tear because the counterclockwise rotation augments the tendency toward:

1. right pronation and knee valgus angulation

– with internal rotation of the tibia relative to the externally-rotating femur, increased stress on the soft tissue structures (e.g. the medial collateral ligament) and increased pressure within the lateral joint compartment (Figs 3.37, 3.81B, 3.82)

2. left supination and knee varus angulation

– with external rotation of the tibia relative to the internally-rotating femur, increased stress particularly on the lateral collateral ligament and increased pressure within the medial joint compartment.

Actually hitting the ball involves a clockwise thoracic rotation which is suddenly slowed, arrested, or even forced counterclockwise as the racquet contacts the ball. If any simultaneous clockwise rotation of the pelvis and lower extremities continues, there results a torsional stress, maximal through the already compromised thoracolumbar junction. In addition, at contact the ball may force the wrist into flexion and/or there is an acute contraction of the right wrist extensors in an attempt to counter any wrist flexion; both manoeuvres exert a jarring force on the origin that can result in a typical lateral epicondylitis or ‘tennis elbow’.

A lay-up in basketball requires a maximum range of trunk and pelvic rotation. Limitations associated with malalignment may make it more difficult to approach the basket from one direction and may, in fact, be responsible for a preference to execute a lay-up from left or right, clockwise or counterclockwise. The risk of injury is increased should circumstances such as the proximity of other players or a blocking of the preferred approach force the player into choosing a different angle or rotating into an already restricted direction in order to complete the lay-up.

Excessive movement into a restricted hip range of motion

‘Right anterior, left posterior’ innominate rotation results in a limitation of right hip flexion and internal rotation, left hip extension and external rotation ( Figs 3.71–3.75). There is, therefore, an increased risk that a quick forward movement of one leg or backward of the other may exceed the available hip flexion or extension range of motion, respectively. In the example given, there would be an increased risk in a lunge with the right leg leading and the left receding (Fig. 5.10C). Similarly, rotation of the body to the right or left over a planted, relatively ‘fixed’, foot may exceed, respectively, the remaining external or internal rotation available for that extremity, possibly to the point of ‘engaging’ the anatomical barrier and causing injury ( Figs 3.78–3.80, 5.14B,C).

Fig. 5.10 Classical fencing: positioning for speed, strength, balance and timing. (A) Side view of a right-handed fencer in the ‘on guard’ position: the right foot is pointing at the opponent, the left foot is at a right angle and the trunk is turned one-half to three-quarters to the front.

(B) Front view of a left-handed fencer in the ‘on guard’ position: the left knee is balanced directly over the foot.

(Courtesy of Pitman 1988.)

Thoraco-abdominal injuries

Injuries involving rectus abdominis, transversus abdominis and external and internal abdominal oblique muscles have been seen to occur more often in tennis players than in those playing handball and racquetball. Lehmann (1988) may well have been right in attributing these injuries to the increased need for overhead activity in tennis. Malalignment can, however, also increase the chance of suffering a sprain or strain of these ‘inner’ and ‘outer’ core muscles with the sudden rotational, reaching and extension movements characteristic of some of these sports (Figs 5.4A,B,C).

Fig. 5.4 Quick twisting and rotational responses. (A) The player is bearing weight on the left leg only. Note: the left foot is supinated; this athlete would be more liable to suffer an inversion sprain if an ‘upslip’ or ‘rotational malalignment’ were present, with the associated shift in weight-bearing toward left supination and functional weakness in left peroneus longus (see Fig. 3.37). (B) Torsional stresses increase risk of injury to soft tissues and joints in thoracic and lumbar spine regions in particular. (C) Overhead serve, a combination of back hyperextention and trunk rotation, results in torsional and ‘jamming’ (compressive) forces on the back. (D) The forward-flexed posture, common to tennis and a number of other competitive sports, predisposes to malalignment when combined with trunk rotation and side-flexion.

(Courtesy of Petersen & Nittinger 2006.)

Injury is especially likely if such movement occurs at a time when that muscle is already shortened by adaptive contracture and/or an increase in tone (e.g. as occurs with ‘facilitation’ and in reaction to pain or instability caused by the malalignment).

Athletes presenting with malalignment sometimes complain of pain in the lateral flank and abdominal region on one or both sides. Problems relating to transversus abdominis or the external or internal obliques can cause pain in these generalized areas, given the overlapping of these muscles and their role as part of the anterior abdominal slings. Tenderness may localize to their origins from the ribs, the main muscle bulk itself or the insertions onto the innominates (Figs 2.31B, 2.32, 2.33).

External abdominal obliques

Most frequently injured, uni- or bilaterally, are the external abdominal obliques (Fig. 2.32) which:

1. originate from the posterolateral aspect of the lower eight ribs and run forward and downward, to

2. insert into the iliac crest and, along with the inferior segment of transversus abdominis and lateral rectus abdominis

3. also insert into the iliohypogastric and ilioinguinal region and onto the lateral aspect of the superior pubic ramus

Tension in the right external muscle is increased by ‘right anterior’ innominate rotation, and by clockwise trunk and counterclockwise pelvic rotation around the vertical axis, also ‘left outflare/right inflare’. Tension increases simultaneously in other abdominal muscles, such as transversus abdominis and rectus abdominis, which are interlinked with the external obliques (Fig. 2.39).

Internal oblique

This muscle originates from the thoracodorsal fascia and anterior iliac crest, inserting into ribs 9-12, through the aponeurosis into the linea alba and to the superior pubic ramus and pectineal line. In the example given above for the effect of ‘right anterior’ rotation on the right external oblique (Fig. 2.32), tension is especially likely to increase in the contralateral (left) internal oblique (Fig. 2.33) if there is a compensatory ‘posterior’ rotation of the left innominate, also with a ‘left outflare’.

Transversus abdominis

Tension will increase in the ipsilateral transversus abdominis (Fig. 2.31). This muscle originates from the lateral inguinal ligament, iliac crest, thoracodorsal fascia and cartilages of the lower ribs, to insert into the linea alba, the superior pubic ramus and the pectineal line.

Rectus abdominis

‘Anterior’ innominate rotation increases tension in the ipsilateral half of rectus abdominis by separating its origin and insertion (Fig. 2.31B). As indicated above, transversus abdominis and the external and internal obliques blend with rectus abdominis and are, therefore, also affected indirectly by tension changes in this muscle.

Tension in all four muscle groups is further increased by reaching and extension movements (e.g. serving in tennis, bowling in cricket, going up for a spike in volleyball). Injury is more likely when rotation, reaching and extension movements occur at a time when these muscles and their tendons are already under increased tension because of pre-existing malalignment (Figs 3.51, 5.4)

Low back pain

Marks et al. (1988) stated that the four strokes used in racquet sports – forehand and backhand ground strokes, the overhead serve and the volley – all put the back at risk. The overhead serve in tennis, for example, is a combined action of rotation and hyperextension of the back (Fig. 5.4B). Rotation occurs through the lower extremities, pelvis and primarily thoracic segment of the spine. Any malalignment-related restriction of movement increases the stress on sites that are already attempting to compensate.

Field hockey deserves special mention here because of the prevalence of low back pain. Part of the problem stems from the constant need to lean or actually bend forward with the trunk while handling and reaching with what, for many of the players, amounts to a relatively short stick. In addition, the trunk is repeatedly rotated clockwise and counterclockwise when attempting to hit the ball from the left or right, respectively. If this manoeuvre is carried out while moving forward, the ability of the pelvis to rotate into the side of the leading leg is at times restricted so that the legs and trunk have to compensate, further increasing the rotational stress (especially on the thoracic spine).

Players may already be aware of a mechanical restriction on wind-up or follow-through. The pelvic restriction is more likely to be to the left, partly because of:

1. restriction of further internal rotation of the left leg and

2. the associated restriction of pelvic rotation around the vertical axis in the transverse plane to that side, especially when both feet are on the ground (Fig. 3.5C).

Pelvic restriction can only increase the stress on the thoracic spine, whose ability to rotate to one side or the other may be further decreased by the rotational displacement of any individual thoracic vertebrae (Fig. 3.49B). It should be remembered that thoracolumbar dysfunction, rather than causing mid-back pain, may be felt as low back pain and also as lateral hip/buttock pain (e.g. as in the ‘thoracolumbar syndrome’ with cutaneous nerve involvement; Fig. 4.23A,B).

Shoulder injuries

Malalignment impairs both shoulder stability and ranges of motion (Fig. 3.17), partly as a result of the:

1. compensatory scoliosis, so the glenoid socket faces downward on the concave and upward on the convex side of the thorax (Figs 2.90, 2.120C)

2. trunk rotation around the vertical axis (increasing the tendency to shoulder protraction on one side and retraction on the other (Chs 3,6)

Those with an ‘upslip’ or one of the ‘more common’ rotational patterns typically show an increase in right external, left internal rotation of the gleno-humeral joint (Fig. 3.17A).

When a player is serving overhead or hitting an overhead volley, the shoulder is initially in a position of maximum external rotation, and the anterior capsule, ligaments and internal rotators are maximally stretched. In someone with malalignment, using the right arm to serve, the increased right external rotation range seen with the malalignment may allow the player to develop more force when serving but:

1. the increased external rotation puts these anterior tissues under even more strain, at the risk of stretching and eventual anterior gleno-humeral joint laxity (Fig. 4.7)

2. a forceful swing-through is more likely to come to an abrupt halt by the limitation of internal rotation on the right side if he or she tries to go through the full ROM (Fig. 3.17A)

3. to avoid stressing these anterior tissues, especially if there is already some discomfort, the player may avoid using the extra external rotation available on the right side and instead compensate by increasing rotation and extension of the spine to ‘wind-up’ for the throw, at the risk of precipitating or aggravating back pain (Fig. 3.18).

In contrast, external rotation will be decreased on the left side and may not allow the player who serves with the left arm to develop as good a force as would be possible when in alignment. Again, the player may try to compensate by increasing spine extension and/or rotation to improve arm external rotation, at the risk of precipitating or aggravating pain especially in the upper back and thoracic spine region.

Groin strain

Balduini (1988: 352) described two mechanisms that can result in groin strain in tennis players, both resulting from an attempt by the player to stop lateral progression.

1. One tends to occur on clay surfaces and involves the leading foot sliding outward. A loss of traction can result in the slide ending up as a split, in which case the adductors, and less often the iliopsoas, can be strained or the lesser trochanter avulsed (Figs 3.50, 5.21)

2. The other mechanism occurs by ‘posting’ the leading foot outward on a surface where the footing is secure, such as a synthetic court. In other words, lateral movement is abruptly stopped. Here ‘the efforts of the adductors and hip flexors are opposed by lateral momentum, and contraction results in muscle tearing rather than the anticipated deceleration’.

The majority of those with the ‘right anterior, left posterior’ rotational pattern present with a restriction of both left hip adduction and abduction range (see also Ch. 6). Tension is typically increased in:

1. the left hip abductors and tensor fascia lata/iliotibial band (TFL/ITB) complex, through ‘facilitation’ (Figs 3.41, 3.44)

2. the iliacus component of iliopsoas (Figs 2.46B,C, 2.59, 3.42, 4.2B), especially when ‘posterior’ innominate rotation is present (which it is more often on the left side; see Ch. 2)

3. iliopsoas as a unit, sometimes unilaterally in an attempt to stabilize an SI joint or decrease pain

4. psoas, as a result of ‘facilitation’ linked to T12, L1 or L2 vertebral rotational displacement.

The combined effect of these restrictions predisposes to injury of the hip adductors, as well as pectineus and the individual components of iliopsoas (Figs 2.62, 4.2. 4.14), with either a lateral ‘slide’ or ‘posting’. Forced adduction can cause pain by compressing these same structures, while putting a tight gluteal/TFL/ITB complex at risk of sprain or strain (Figs 3.41, 3.44Aiii, 5.17).

Reference should also be made at this point to the occurrence of a painful hemipubic bone in court sports as a result of irritation of the anterior cutaneous branches in association with T12/L1 rotational displacement and the ‘thoracolumbar syndrome’ (Fig. 4.23A2,B2; Appendix 9). These branches are vulnerable especially in those playing tennis or soccer (Maigne 1995). Certainly, repeated trunk hyperextension and reaching manoeuvres (e.g. serving), as well as excessive or repetitive hip extension stressing the back, will put the anterior branches under stretch while simultaneously narrowing the intervertebral foraminal outlets as the player leans backward.