The third tenet states that structure and function are inter-related. Bodies have architectural (anatomical) form and engineering (physiological) processes that intimately influence each other. In the pelvic girdle, if there is sacroiliac dysfunction or lumbosacral torsion, a patient may have mechanical or structural back pain that might contribute to bowel dysfunction or urinary problems (Beal 1985, Browning 1990, Tettambel 2005). Conversely, if a woman has a difficult pregnancy or childbirth, she may develop pelvic pain as a result of a caesarean section or vaginally delivering a very large baby with or without instrumentation. Over time, the pain may become chronic, affecting her posture and gait (Ronchetti et al. 2008); and she may not anticipate another pregnancy with a positive attitude. Thus, the fourth osteopathic key tenet is pertinent: rational treatment is based upon the three previous principles. In this instance, to restore normal functionality, rational treatment may consist of postpartum spinal and extremity manual therapy; exercise to maintain stability and encourage flexibility of her musculoskeletal system; and perhaps family planning counselling to allow her to care for herself and her family.

Each of the above principles is important to the understanding of somatic dysfunction. Somatic dysfunction can be defined as ‘impaired or altered function of related components of the somatic (body framework) system: skeletal, arthrodial and myofascial structures and their related vascular, lymphatic and neural elements’ (Educational Council on Osteopathic Principles 2009). When a patient presents with PGP, the clinician should consider whether there is a somatic component to the chief complaint, injury or illness:

• Where in the soma might the problem exist?

• How does it manifest?

• Although the presenting painful condition may involve the pelvic girdle, could other bones, muscles, ligaments, nerves, vasculature, pelvic organs, fascia and/or related structures be primary features? (See Chapter 9.)

There may also be other relationships between the pelvic container and its contents, potentially affected by posture, gait and pulmonary ventilation (see Chapter 11). Somatic dysfunction could also be the result of a neurophysiological phenomenon, i.e. peripheral or central sensitization (Howell & Willard 2005) (see Chapter 3 for physiological mechanisms). Reflex loops of visceral and somatic excitation and facilitation may also be involved, introducing autonomic and referred pain to the equation (Janig 2008).

If there is a disturbance of the normal function of somatic structures, how might the problem best be addressed? Somatic dysfunction possesses characteristics identifiable by means of palpation to appreciate static or motion asymmetry of the body, as well as changes – structural and physiological – in other body tissues or systems. Osteopathic clinicians who perform osteopathic manipulative treatment (OMT) commonly use a combination of tests that evaluate the patient for signs of sensitive or tender points, tissue texture abnormalities in the soft tissues surrounding the spinal and pelvic joints, asymmetry of anatomical landmarks and alterations in quality or quantity of range of joint motion (Dinnar et al. 1982, Beal 1982, Fryer et al. 2009). A useful mnemonic, ‘STAR’, may be helpful to establish a palpatory structural diagnosis that may be amenable to manipulative treatment (Educational Council on Osteopathic Principles 2009) (see Box 14.1).

Box 14.1 STAR mnemonic used to establish a palpatory structural diagnosis amenable to manipulative treatment

• ‘S’ represents sensitivity. Sensitivity may occur as the result of tissue contact or pressure that would not be sufficient to cause discomfort in ‘normal’ tissues. This may be reported as tender or painful by the patient when being palpated. To establish a diagnosis of somatic dysfunction, sensitivity may or may not be present. Sensitivity may be subjective and not always a reliable indicator of dysfunction. However, a patient may not be aware of any pain until a structure is palpated. Usually, a patient with a complaint of pain may be anxious about the performance of a palpatory exam and report increased tenderness on palpation of a structure because the structure was palpated (Fryer et al. 2004a).

• ‘T’ represents tissue texture abnormality that is palpable evidence of physiological dysfunction. Palpable changes found in skin, subcutaneous tissue, fascia and muscles reflect disturbances in local tissues, related organs or specific spinal segments. Tissue changes can be acute or chronic somatic dysfunctions. In acute dysfunction, one can palpate warmth, moisture, as well as bogginess and increased tension of tissues. Oedema may be present. Conversely, in chronic dysfunction, the tissues may feel cool, thin, dry and ropey (O’Connell 2003, Fryer et al. 2005).

• ‘A’ represents structural asymmetry, which may be observed or palpated. Anatomical landmarks, such as iliac crests or trochanter heights, can be visualized to compare bilateral location. These landmarks can also be palpated to assess position bilaterally as well (Beal 1982).

• ‘R’ represents range of motion. This motion may be either active or passive with quantitative and qualitative features. To evaluate joints of the pelvic girdle by palpation, one must note how much the joint moves and how well it moves. What restrictions to normal motion are present? Where are the anatomical, restrictive and pathological barriers in both active and passive motion testing? How do these barriers affect local joint motion as well as the rest of the pelvis (Beal 1982)? Ultimately how does this dysfunction affect the body as a unit of function (Tettambel 2005)?

When the pelvic girdle is restricted, gait and posture change (van Wingerden et al. 2008). Persistent PGP can negatively affect the patient’s attitude about ability to function, sometimes to a state of depression and altered sensorium due to chronicity of the problem (Gutke et al. 2007). Pelvic girdle motion may also be restricted by pelvic organ pathology (Beal 1985). A bimanual pelvic exam may detect a mass, pelvic inflammatory disease, adhesions from infection or surgery, or possibly signs of endometriosis (Tettambel 2005). In addition to restriction of motion, pain may be elicited (Boyle 2008). However, in a patient with PGP due to somatic dysfunction, the primary objective should be to treat the dysfunction underlying the pain (Damen et al. 2001).

Used alone, digital pain provocation for sensitivity of the soft or osseous tissues is the most reliable of the four types of palpatory tests in the neck and back regions (Seffinger et al. 2004, Stochkendahl et al. 2006). Lumbar percussion for pain provocation is very specific, so it can be used as a screening test; if it reproduces the patient’s reported pain, then there is indeed a truly painful condition at that location (Kristiansson & Svardsudd 1996). It must be understood that reliability of pain provocation tests does not indicate that more than one examiner can reliably feel or interpret the sensitivity of the palpated tissues; rather that a patient can reliably state repetitively that a palpated site is sensitive when palpated by different practitioners (Seffinger et al. 2004, Haneline & Young 2009). Soft tissue tests assessing for tissue texture abnormalities, altered compliance or presence of muscle tension are in general not reliable when used as the sole source of palpatory information (Seffinger et al 2004, Stochkendahl 2006, Haneline & Young 2009). Although regional range of motion tests are more reliable than segmental range of motion tests, motion tests for SIJ or lumbar mobility are not in general reliable (Hestbaek & Leboeuf-Yde 2000, van der Wurff et al. 2000a, 2000b, Seffinger et al. 2004, Stochkendahl 2006, Robinson et al. 2007). However, using a cluster of pain provocation tests combined with motion tests improves reliability (Arab et al. 2009). Likewise, combinations of pain provocation tests have demonstrated validity (Van der Wurff et al. 2006, Hancock et al. 2007, Szadek et al. 2009). Pelvic distraction, thigh thrust, compression and sacral thrust tests in combination are accurate in detecting the SIJ as a source of pain (Laslett et al. 2003, 2005). When all tests do not provoke pain, the SIJ can be ruled out as a source of the pain. One study demonstrated that the maximum interexaminer reliability occurs when only the result of the most reliable test is used to determine the side of SIJ dysfunction, sacral base position and innominate bone position (Tong et al. 2006).

The European guidelines for physical diagnosis of PGP (Vleeming et al. 2008) recommend using the following tests as they have demonstrated reliability:

In pregnant women, the most accurate combination of pain provocation palpatory tests to detect the location of sacroiliac or lumbosacral pain is:

• Motion tests of femoral compression, lumbar movement and supine iliac gapping (Kristiansson & Svardsudd 1996, DonTigny 2005a, 2005b);

• Digital pressure to assess the sacrospinous ligament and posterior superior iliac spine (Kristiansson & Svardsudd 1996);

• Lumbar spine percussion (Kristiansson & Svardsudd 1996).

Using a combination of reliable lumbar and pelvic motion and sensitivity assessment tests in pregnant patients with non-specific lumbopelvic pain, two examiners were able to reach substantial agreement in differentiating patients as having either lumbar pain or PGP (Gutke et al. 2009). This is useful since up to 25% of patients presenting to a spine specialist pain clinic with low back pain are likely to actually have PGP (sacroiliac and/or hip as pain generator) (Sembrano & Polly 2009). If primary care clinicians were better at screening patients with low back pain, unnecessary referrals to specialists would result, limiting unnecessary expenditures of precious personal and healthcare industry financial resources.

Evaluation of the pubic symphysis and tubercles for levelness and tenderness is used to determine imbalance of forces attached there, including the rectus abdominis muscles and sheath, thigh adductor muscles (adductor magnus, longus and brevis, the gracilis and the pectineus), inguinal ligament and pelvic floor muscles (levator ani and coccygeus) (Greenman 2003).

The information outlined above forms a foundation for understanding an osteopathic approach to assessing and treating patients with PGP (Jordan 2006). Beyond palpatory evaluation for evidence of somatic dysfunction (i.e. assessing for STAR), additional information may help to determine treatment plans. Patient gender, age, professional and social activities, attitude, as well as other factors help determine the approach to evaluation and a care plan.

• Dancers, for example, commonly complain of lumbopelvic and various musculoskeletal pain at various times in their career depending on the demands placed upon them by the choreographer, the environment, their skill, age, coping ability and experience (Demann 1997, Hincapié et al. 2008).

• Athletes of sports that entail increased mechanical load on the lumbosacral spine and pelvis are at higher risk for PGP and low back pain (Bahr et al. 2004).

• The elite athlete has special considerations as well (Bo & Backe-Hansen 2007).

• The type of employment may affect the cause and nature of PGP. For example, the main biomechanical risk factors identified for the development of low back work-related musculoskeletal disorder were heavy physical work, awkward static and dynamic working postures, and lifting; the psychosocial risk factors identified were negative affectivity, low level of job control, high psychological demands and high work dissatisfaction; individual risk factors identified were younger age and high body mass index (da Costa & Vieira 2009).

• Motor vehicle collision survivors might have injuries from steering wheel blows to the pelvis, compression of door panels into the hip, lapbelt-incurred lumbopelvic torsions, or femoropelvic compression from floorboard and pedal ground forces at time of impact; or when bracing in preparation of the impending event.

• Older adults may have developed posture or gait disorders due to trauma (falls, accidents), or disease (neurological, vascular, cataracts) that can affect pelvic girdle mechanics.

• Young females who participate in sports may have ligamentous laxity, making them more susceptible to injury (Bo & Backe-Hansen 2007). Pelvic ligamentous laxity is helpful in childbearing years, but not desirable in menopause (Gabbe 2007).

• Pregnancy and birth trauma may result in chronic PGP (Latthe 2006, van der Hulst 2006).

• Sexual trauma may also result in pelvic pain and dysfunction.

• Postmenopausal women are at risk for pelvic organ prolapse, bladder or bowel incontinence, osteoporosis and degenerative arthritis (Prather 2007). Hormonal factors also influence pelvic structures, function and pain (O’Sullivan & Beales 2007, Eberhard-Gran & Eskild 2008).

• Women who work outside the home may develop pain due to ‘wardrobe malfunctions’ of restrictive clothing or uncomfortable shoes (Chen et al. 2005), as well as postural challenges that accompany manual labour or repetitive actions.

• Obesity as a result of pregnancy, endocrine problems, or poor nutritional habits contributes to pelvic girdle dysfunction (Mottola 2009).

An osteopathic approach to the patient with PGP would start with collection of historical information and the performing of a comprehensive physical examination, including a palpatory structural examination. A patient-centred treatment approach would investigate what would be required to promote health in the presence of challenging situations. In osteopathic literature there are five conceptual treatment models to promote health and modify disease (pathological) processes (Educational Council on Osteopathic Principles 1987, 2009, Hruby 1991, 1992). As the body is an integrated whole, posture, neural responses, respiration/circulation, metabolic processes and behaviour are tightly woven together; dysfunction of any of these coordinated body functions will therefore compromise the entire organism. Each of these models is discussed in this chapter, with intended therapeutic benefits, within the four key principles outlined above.

Biomechanical model

The biomechanical model requires knowledge of posture and motion as they relate to PGP and dysfunction (see Box 14.2). The patient should be observed in active posture as well as in the resting supine position. Palpatory examination using the combination of elements of STAR should be employed. It is necessary to consider how motions of the pelvic container affect both motion and function of the pelvic contents. Also requiring consideration is how pelvic dysfunction relates, from cause-and-effect perspectives, to the spine, abdomen, rib cage, lower and upper extremities. The spinal curves, lateral as well as anterior-posterior, require assessment, with consideration of their effect on muscle length and tension. Posture is assessed when standing or sitting from anterior, posterior and lateral views. Notes on postural influences are to be found in Chapter 11. Orthopaedic tests help determine structural and functional involvement of particular lumbopelvic components (Liebenson 2004, 2007). When evaluating the patient, painful structures usually denote muscle spasm or hypertonicity, but may also indicate peripheral and/or central sensitization (Howell & Willard 2005) or the result of decreased muscle activity (Fryer et al. 2004b). The antagonists to hypertonic muscles may be inhibited. Short- and long-term (up to 2 years) outcomes improve with an individualized exercise programme addressing muscle imbalance to relieve such weakness or inhibition (Stuge et al. 2004a, 2004b). Presence of rectus abdominis muscle diastasis, especially in post partum women, should be assessed and treated due to the effect it can have on the integrity of the abdomino-pelvic ‘canister’ and its functions in providing postural stability, controlled bladder function and efficient breathing mechanics (Lee et al. 2008).

Box 14.2 Biomechanical aetiological features

The bony pelvic girdle comprises right and left ilia (with pubes and ischia) which constitute the hemipelvis, plus the sacrum. Each hemipelvis arises embryologically from three bony islands that join flexibly in the acetabulum by the age of 8 years. Each side also has three joints – sacroiliac, hip, pubic symphysis – and so can be considered most balanced and stable when all three ‘legs’ of the stool are level and moving well. Because the pelvis serves for ambulation and stance, as well as for containment of truncal contents and passage of bodily functions, such a balancing act is dynamic even at rest.

• Congenital deformities such as small hemipelvis, club foot, facet asymmetry in the lumbosacral spine, partial or complete sacralization of the fifth lumbar, spondylolisthesis, spina bifida occulta, or butterfly (or bat) wing process can alter lumbopelvic biomechanics (Bailey & Beckwith 1937). Most of these conditions are discovered by X-ray, when there is an unsuccessful course of conservative care, which may have included manipulation. They may or may not be related to PGP and may or may not require surgical correction. Spine surgical consultation is indicated if symptoms do not improve or worsen with conservative measures.

• Anatomical short leg can cause sacral base unlevelling and pelvic asymmetry related to lumbopelvic pain (Juhl et al. 2004). Posture and gait can be affected with resultant musculoskeletal imbalance, scoliotic spinal curves and pain (Juhl et al. 2005). Heel lift therapy should be considered in patients with PGP and low back pain associated with unlevel sacral base due to anatomical short leg (Lipton et al. 2009).

• Injury to the coccyx due to trauma or childbirth can affect sacral motion via its ligamentous attachments (Meleger & Krivickas 2007). Ligamentous strains of the coccyx can also affect motion of the ilia and ischia, as well as cause pain in the pelvis, perineum and lower extremities. Coccygeal muscle pain can persist despite normalization of sacral dynamics due to the strong ligamentous spans retaining positional strain patterns; the authors have noted that some patients with persistent coccydynia complain of coccygeal pain with bowel movements, micturition, coitus, and upon sitting, standing or moving, likely because two-thirds of the levator ani sling muscles involve the coccyx.

• Lumbopelvic somatic dysfunction can compromise pelvic diaphragm (levator ani and coccygeus muscles) balance and functions, resulting in pelvic floor pain and bladder dysfunction (Pool-Goudzwaard et al. 2005, Arab et al. 2010). Bowel function may also be compromised (Ng 2007).

• Pelvic obliquity can arise from imbalances of the iliopsoas muscles and quadratus lumborum muscles. These form the deepest of the lumbopelvic core muscle layers.

• Difficult childbirth may induce pubic shears or avulsions. In addition to painful gait, dyspareunia with sexual dysfunction and bladder voiding dysfunction can result.

• In the Mitchell model of the ‘walking cycle’, the transverse axis for gait is through the pubic symphysis. Shears and compression strains would not only affect gait, but posture and pelvic bowl tilt as well (Greenman 2003). Movement at the pubic symphysis may be small, but intense pain on standing (on one leg) or walking may be reported by the patient when dysfunction exists (Greenman 2003).

Mitchell (1958) was an osteopathic pioneer in the development of a biomechanical model to explain the role of the pelvis in posture and gait. Mitchell also collaborated in the development of muscle energy technique (MET), a modality employed to treat somatic dysfunction (Goodridge 1981). This approach and his techniques have been adopted widely across professions and cultures. When joints such as SIJ are altered from their ideal positioning, or if inflammation or joint fluid pressures are elevated, inhibited motion occurs, often with resultant pain (Howell & Willard 2005). Muscle energy techniques (MET) may be used to balance muscle tone (i.e. stretch hypertonic muscles and strengthen hypotonic muscles), relieve asymmetrical forces upon spinal and peripheral joints, and enable restoration of normal joint motion (Wilson et al. 2003, Selkow et al. 2009). Benefits of MET manipulation alone, and combined with exercise, are beginning to be assessed by randomized clinical trials (Wilson et al. 2003, Selkow et al. 2009). Further studies are needed, especially in the contexts of the patient’s age and other activities of daily living.

Gait (or other means of locomotion) should be assessed for its cadence, symmetry, rate and reported ease through repeated visual or kinematic observation. Specific patterns of muscle activity have been fitted into the six determinants of the gait cycle (Kerrigan et al. 2000, 2001, Esquinazi & Mukul 2008). In patients with PGP, muscle activity patterns are not only altered during gait (Wu et al. 2008), but also during the active straight leg raising (ASLR) test as compared with pain-free subjects (O’Sullivan et al. 2002, Beales et al. 2009a, 2009b). Researchers found increased minute ventilation, decreased diaphragmatic excursion (O’Sullivan et al. 2002), increased intra-abdominal pressure (Beales et al. 2009a, 2009b) and increased pelvic floor descent (O’Sullivan et al. 2002, Beales et al. 2009a, 2009b) during the ASLR test in PGP patients, indicating considerable widespread effects on the neuromuscular control of respiration and pelvic floor function. Interestingly, enhancement of pelvis stability via manual compression through the ilia reversed these differences (O’Sullivan et al. 2002, Beales et al. 2009a, 2009b). Hu et al. (2010) therefore reasoned that since manual pelvic compression restores normal abdominal and pelvic motor control in patients with PGP during the ASLR test, a pelvic compression belt worn while walking might provide similar stabilizing effects. Nulligravid women walked on a treadmill at increasing speeds while wearing or not wearing a belt. Simultaneously, there was fine-wire electromyography (fwEMG) of the psoas, iliacus and transversus abdominis muscles and surface EMG (sEMG) of other hip and trunk muscles. Wearing a pelvic belt while walking reduced core abdominal muscle activity and induced contralateral activation of biceps femoris and gluteus maximus, thus promoting anterior tilting of the pelvis and enhancing force closure effects. Thus, poor force closure of the SIJs may be a key component of the altered gait, respiration and pelvic floor mechanics observed in some patients with PGP. Pregnancy adds another mechanical challenge to the patient with form and force closure problems. Wu et al. (2004) compared gaits of healthy women who were pregnant or nulligravid and found them to be very similar except for increased antiphase pelvis–thorax coordination among pregnant subjects walking quickly; the difference is greater among women with PGP while pregnant (Wu et al. 2008).

Pelvic mechanics are also altered in men who have PGP. Hungerford et al. (2004) did kinematic assessment of pelvic bone motion in men with posterior pelvic pain (PPP) compared to men without PPP. Posterior rotation of the weight-bearing innominate was observed in controls, while anterior rotation during weight-bearing occurred in symptomatic men.

Sacral motion can occur around a variety of axes: anteroposterior, vertical, horizontal or oblique (Beal 1982). It is most likely, however, that there is no stationary sacral axis and that the axis shifts with the introduction of movement (Beal 1982). Sacral and lumbar spine motions are often impaired in patients with PGP (Beal 1982, van Wingerden et al. 2008). Sacroiliac motion can be restricted at the superior or inferior aspects of the SIJ; compression can also occur (Beal 1982, Vleeming et al. 1990a, 1990b). There are no muscle attachments directly connecting the sacrum to the pelvic girdle. The sacrum is suspended between the ilia by ligaments. Its motion is influenced by joint surface (form closure) and myofascial and ligamentous function (force closure) (Vleeming 1990a). Ligamentous strains or laxity during pregnancy can disrupt joint mechanics, cause low back and pelvic girdle pain (Damen et al. 2001), and contribute to muscle imbalances in the pelvis, lower extremities and trunk of the body. In gynaecology patients, evaluation of sacral motion and dysfunction, along with pelvic girdle motion, should be assessed. On clinical gynaecological examination, strains of the broad ligament and uterine malpositioning may be inter-related with altered bone and joint mechanics (Barney 2008, Boyle 2008). The abdominal, lumbar, pelvic and lower extremity myofascial tension affects SIJ stiffness and stability (Van Wingerden et al. 2004). Patients with PGP with or without low back pain have altered standing posture and forward-bending motions (Van Wingerden et al. 2008). Therefore, it is important to assess and treat not only contiguous bony and ligamentous structures but the back, pelvic and extremity muscles and fascia as well, in helping the patient resolve not only the PGP, but to restore and maximize gait, posture and motion.

Hip range of motion impacts lumbopelvic integrity (Liebenson 2004, 2007) and should be checked in all directions to assess its six muscle groups. Janda (1977, 1986) found that prone hip extension reveals hamstring strain substitution for gluteus maximus activation. Nadler et al. (2002) associated impaired hip extension with propensity for low back pain in women. Vleeming and colleagues (2007) have written extensively about the biomechanical integration of rectus femoris muscle and sacrotuberous ligament as a key component of form closure and force closure affecting the long dorsal sacroiliac ligament and other pelvic girdle structures. Janda (1977, 1986) and Nadler et al. (2002) also found that weak hip abductors contribute to lumbopelvic instability and motor control substitution. Hip pain is also increased with lumbar hyperflexibility more frequently than stiffness (Biering-Sorensen 1984). Hip external rotation is likely to show lumbopelvic dysfunction than internal rotation (Liebenson 2007).

There is marked similarity between osteopathic and physical therapy assessments of dysfunction present in patients with PGP as evidenced by correlating the reports from Greenman (1996) with the integrated pelvic girdle model of Vleeming et al. (2007) and Lee (2004) (see Table 14.1).

Table 14.1 Osteopathic and physical therapy assessments of dysfunction

Somatic dysfunctions (SD) in persistent low back pain (Greenman 1996)	Integrated model of pelvic girdle: form closure, force closure, motor control, emotional awareness (Lee 2004, Vleeming et al. 2007)
Non-physiological pelvic SD (pubic shears)	Core, abdomen, pelvic floor and hip adductor muscles imbalance at pubic tubercles and rami
Non-physiological pelvic SD (sacroiliac shears)	Improper load distribution of sacroiliac joint (SIJ)
Sacral nutation failure (including non-neutral and backward sacral torsion SD)	Flexion (nutation): sacrotuberous ligament-biceps femoris Extension (counternutation): long dorsal sacroiliac ligament
Pelvic tilt/‘Short-leg syndrome’/unlevel sacral base	Impaired pelvic–trunk coordination
Muscle imbalance (including psoas syndrome)	Global muscle and core muscle faulty recruitment
Lumbar single level (Type II) lumbar SD	L5 associated with SIJ dysfunction

Osteopathic manipulative treatment options (see Box 14.3)

Osteopathic manipulative treatment (OMT) has been shown to be efficacious in treating chronic low back and pelvic pain (Licciardone et al. 2005), low back pain during pregnancy (Licciardone et al. 2010), pelvic pain from chronic prostatitis (Marx et al. 2009), and is advocated for women with chronic pelvic pain (Tettambel 2007) and patients with PGP (Greenman 2003). When diagnosing and treating somatic dysfunction with OMT, choosing the type of manipulative procedure appropriate for the patient requires training and experience.

Box 14.3 Osteopathic terminology (ECOP 2009)