5.1 Introduction
5.1.1 Lumbar-Pelvic-Hip Region
The lumbopelvic-hip (LPH) region is a functional unit composed of the hip joints, pelvic connections, and the lumbar spine. As this book addresses the precise palpation of the joints of the limbs, the lateral and anterior hip complex will be selected and discussed in detail. The posterior hip and pelvic region is discussed in Chapter 9.
5.1.2 Functional Significance of the Pelvis and Hip Joint
The LPH region is subject to the principles of bipedal locomotion, as is the case for the entire construction of the lower limb. Support and locomotion are the most important aspects of these principles.
With this in mind, the first role of the LPH region is to form a connection between the lower limbs and the trunk. The sacroiliac (SI) joints are very large and rigid in comparison to the more delicate sternoclavicular joint that forms the junction between the upper limb and the trunk. The very steep articular surfaces and the tilted position of the sacrum make the construction and ligamental stability in the SI joint complicated in many respects.
The small movements observed in the SI joints and the pubic symphysis are especially necessary to cushion the transmission of loading, that is, for shock absorption. The principle of shock absorption is not only seen in the pelvis, but is also demonstrated in all sections of the lower limbs.
The complex connection between the lower limbs and the vertebral column also results in movement of the hip joint being transmitted directly onto the vertebral column. Movements of the pelvis and more superior movements acting on the pelvis also affect the other components of the LPH region. This becomes clear when looking at the example of hip extension. The normal range of hip extension is 10 to 15°. This movement is transmitted very quickly onto the articulations of the pelvis (SI joints and symphysis) and from there immediately onto the inferior segments of the lumbar spine.
While sitting, the pelvis transfers the load of the body to the surface on which the individual is seated or standing, and not to the legs.
Especially thick parts of the ilium transfer the load of the body from the SI joint to the acetabulum when the individual is upright.
5.1.3 Pathology and Common Applications for Treatment in this Region
The hip symptoms encountered in daily practice are numerous and very varied. If pain in the buttocks and groin is reported, functional differentiation of the pain generators is a diagnostic challenge that often requires considerable time and effort. The pain can originate in the lumbar spine, the pelvic connections, or the hip joints. The pain generators in pelvis and hip can be a variety of tissues: capsules, subchondral bones, labrum of the acetabulum, muscular insertions, tendons, bursae, peripheral nerves. An additional complication is the fact that pain generators close to the trunk can transmit symptoms as referred pain or pain projected to the legs, and this can extend the area in which pain is perceived (Lampert, 2009). For this reason, it is advisable when examining the LPH region to include in the diagnosis all components of the motor apparatus that could be possible causes of the symptoms.
Common Pathological Conditions in the Hip
Lateral hip symptoms: Soft-tissue conditions over the greater trochanter (tendinosis, trochanteric bursitis) and referred pain in the hip joint.
Local posterior hip symptoms: Insertion tendinopathy of the ischiocrural muscles, piriform syndrome, hamstring syndrome, femoroacetabular impingement, lesions of the acetabular labrum.
Groin pain: Insertion tendinopathy (e.g., of the adductors), irritation of the pubic symphysis, referred pain originating in the lumbar spine or the SI joint, and naturally, problems in the hip joint (arthrosis, arthritis, labrum lesion, femoroacetabular impingement), compression neuropathy.
This selection is just a partial listing of all the hip and groin symptoms that are commonly met in a physical therapist’s practice. Symptoms that occur on the dorsal aspect of the pelvis often originate in a pain generator in the spinal column or the sacroiliac joint.
Most hip and groin symptoms can be differentiated from one another by using special tests during assessment. Precise palpation is nevertheless required when tests do not help the therapist and when the exact position of the lesion needs to be identified and confirmed.
5.1.4 Required Basic Anatomical and Biomechanical Knowledge
To understand instructions for local palpation, the student needs some essential background information:
The bony construction of the pelvis, especially the accessible elevated areas of bone.
The geometry of the proximal femur, especially the femoral neck anteversion (FNA) angle.
The names and positions of the muscles that cross over the hip joint with special emphasis on the extensors and adductors.
Bone Anatomy
Pelvis
The remarkable aspect of the bony pelvis is the three-dimensional construction of the large bones that form a ring. It is very difficult to illustrate this in the two-dimensional illustrations that are available to therapists. Therefore, it is important for the therapist to develop the ability to visualize the structure of the ring from different perspectives.
The bony landmarks of the pelvis, whose precise location will be discussed in this section, mainly lie on the anterior aspect (▶ Fig. 5.1).
These are consolidated into the anteriorly accessible sections of the ilium and pubis.
The local anatomy of the deep structures in the posterior pelvis will also be addressed in this section on palpation of the hip region (▶ Fig. 5.2).
The ischial tuberosity is the only posterior reference point that will be sought. All other structures will be discussed in Chapter 9.
Pubic Symphysis
The symphysis, an important component of the pelvic ring, exerts significant control of the hip bones and strongly influences the SI joints. This means that the symphysis offers the greatest resistance to the effects of movement on the pelvic ring.
It is very long, at 4 to 5 cm, but this is not apparent because it is tilted approximately 45° from anterocranial to dorsocaudal (▶ Fig. 5.8). In the middle, between the two symphyseal rami of the pubic bone, is a fibrocartilaginous disk. This interpubic disk varies in thickness and develops, from the age of 10, an increasingly wide articular cavity, which, from the age of 30, develops a synovial membrane. The symphysis is stabilized by the superior interpubic ligament and the arcuate ligament of the pubis. The arcuate ligament is the most important stabilizer. It consists of thick fibers running in an arc, which insert directly medial to the insertions (origin) of the gracilis on the rami of the pubic bone. Large shear forces can lead to irritations at this point; these shear forces arise with loading on a single foot. In walking, there is a vertical and ventral translation of 2.2 and 1.3 mm respectively (Meissner, 1996).
Through its highly differentiated innervation (ilioinguinal and genitofemoral nerves, T12-L2, as well as the pudendal nerve, S2-S4), the symphysis is a potential pain generator with a uni- or bilateral pain perception area in the lower abdomen, anal, and genital areas and toward the medial thigh. Arthropathies of the symphysis are divided into four stages and are often associated with instability (increased translation). Palpation to locate an irritated muscular structure in adductor problems should always include the possibility of symphyseal irritation.
Hip Joint
The geometry of the bones in the joint can predispose the hip joint for certain pathologies: femoroacetabular impingement with/without lesions of the acetabular labrum, as well as coxarthrosis. The hip joint undergoes multiple changes during development, and individual variations of the spatial relation between femoral head and acetabulum are the rule.
The variations in size given for the caputcollumdiaphyseal (CCD) angle are well known. This angle describes the superomedial orientation of the femoral head with respect to the shaft; at birth it is approximately 150°. Reduction of the angle with advancing age to approximately 133° at the age of 15, and even lower in adults, varies inter- and intraindividually. Overall, there is agreement in the literature that a coxa vara exists from approximately 120° and less. This can favor the occurrence of a femoroacetabular impingement between the collum femoris and the border of the acetabulum. A CCD angle of over 135°, a coxa valga, is a predisposing factor for early coxarthrosis but also involves the danger of overloading the labrum at the superior edge of the acetabulum (Matthijs et al., 2003).
The antetorsion angle (ATA) is one of the determinants of the hip joint’s degree of rotation. The greater it is, the greater is the inward rotation capacity of the hip joint in normally elastic soft tissue (capsule and muscles). The ATA determines the degree of anterior twisting of the femoral neck with respect to the shaft. In drawings, the position of the shaft is usually represented as a transverse connection through the condyles at the distal femur (▶ Fig. 5.3).
Children have a large ATA (Rudorff 2007) and can therefore often achieve remarkable inward rotation. As the skeleton grows, the ATA is reduced to an average of 14 to 15° (von Lanz and Wachsmuth, 2004) as variously reported in the literature. Reduction of the 35° ATA of early childhood (Matthijs et al., 2003) results in inter- and especially intraindividual differences.
Determination of the ATA is of interest when it is found that there is a difference in rotational capability of the hip joints between one side and the other. The degree of inward plus outward rotation should always be the same. The ATA determines the distribution in favor of inward or outward rotation. However, this widespread opinion of teachers in the field of physical therapy was challenged by Tavares Canto et al. (2005). In his study, he found no significant correlation between the ATA and the degree of rotation, so the conclusion must be drawn that additional parameters, such as the geometry of the acetabulum, influence hip rotation.
Manual determination of the ATA by palpation of the lateral major trochanter has special importance in preoperative diagnosis of children with cerebral palsy, before derotation osteotomy. There are also validation studies from authors (Ruwe et al., 1992; Chung et al., 2010) that confirm the accuracy of this test.
The greater trochanter is especially easy to access on the femur. The remaining structures are either hidden by thick layers of soft tissue or can only be identified using guiding structures.
The size of the greater trochanter in living subjects is astonishing. For example, the posterior area between the trochanter and the lateral border of the ischial tuberosity amounts to only approximately 2 to 3 finger widths.
Once again, illustrations and common anatomical models cause confusion as the trochanter is too small in these examples and the spatial relationship to the pelvis too large.
In recent years, the geometry of the acetabulum coxae has also been substantiated. It is angled in all three planes. In the frontal plane, the angle is approximately 60° in children and approximately 45° to the transverse in adults (▶ Fig. 5.4). In the transverse plane, the acetabulum is often not uniformly inclined laterally out of the sagittal plane. The upper portion describes an approximately 20° angle, the lower a 45° angle, which creates a distinct torsion of the acetabulum. In the sagittal plane, the acetabulum is tipped backward by approximately 30°, which causes the notch in the acetabular edge to point down and forward.
Relevant Anterior Soft Tissues
The position of the anterior muscles is usually divided into the following:
This topographical classification aids orientation on the anterior aspect.
The lateral femoral triangle is bordered by the following:
This area is actually not a triangle, but is instead shaped like an arrowhead with its tip pointing upward. The triangle does not have a third border. The two participating muscles are in contact with the anterior superior iliac spine (ASIS). This is the most important osseous orientation point on the anterior pelvis.
The anterior inferior iliac spine (AIIS) and rectus femoris are found deep in this triangle.
The medial femoral triangle is the actual trigonum femorale (femoral triangle) and was first described by the Italian anatomist Antonio Scarpa (1752–1832). It is a proper triangle and is formed by the following:
The sartorius (medial edge of the muscle belly).
The adductor longus (medial edge of the muscle belly).
In addition to the previously mentioned ASIS, the pubic tubercle is also another important bony point for orientation.
Knowledge of this triangle helps the therapist to locate lesions in the clinically important flexor and adductor muscle groups. Furthermore, the position of the large neurovascular bundle directly anterior to the hip joint can be identified.
The following are the structures (from lateral to medial) (▶ Fig. 5.7):
The vessels leave the pelvic space together and cross under the inguinal ligament in the vascular lacuna, while the nerve accompanies the iliopsoas muscle passing through the lacuna musculorum. The inguinal ligament is a gathering of fasciae of the anterolateral muscles, thus not a real ligament in the usual sense. It extends between the ASIS and the pubic tubercle, another important osseous landmark. Lateral to the ASIS, the inguinal ligament is very flat and tapers visibly along its spiral course to medial. The groin (sulcus inguinalis) only coincides with the inguinal ligament in thin individuals. With an even slightly increased proportion of body fat, the groin falls below the level of the ligament. The superficial inguinal lymph nodes lie in the groin; they will not be discussed further here. The inguinal area cranial to the inguinal ligament is explained in Chapter 11.
Pubic Symphysis
The symphysis, an important component of the pelvic ring, exerts significant control of the hip bones and strongly influences the SI joints. This means that the symphysis offers the greatest resistance to the effects of movement on the pelvic ring.
It is very long, at 4 to 5 cm, but this is not apparent because it is tilted approximately 45° (Mens et al., 1999) from anterocranial to dorsocaudal (▶ Fig. 5.8). In the middle, between the two symphyseal rami of the pubic bone, is a fibrocartilaginous disk. This interpubic disk varies in thickness and develops, from the age of 10, an increasingly wide articular cavity, which, from the age of 30, develops a synovial membrane. The symphysis is stabilized by the superior interpubic ligament and the arcuate ligament of the pubis. The arcuate ligament is the most important stabilizer. It consists of thick fibers running in an arc, which insert directly medial to the insertions (origin) of the gracilis on the rami of the pubic bone. Large shear forces can lead to irritations at this point; these shear forces arise with loading on a single foot. In walking, there is a vertical and ventral translation of 2.2 and 1.3 mm respectively (Meissner, 1996).
Through its highly differentiated innervation (ilioinguinal and genitofemoral nerves, T12-L2, as well as the pudendal nerve, S2-S4), the symphysis is a potential pain generator with a uni- or bilateral pain perception area in the lower abdomen, anal, and genital areas and toward the medial thigh. Arthropathies of the symphysis are divided into four stages and are often associated with instability (increased translation). Palpation to locate an irritated muscular structure in adductor problems should always include the possibility of symphyseal irritation.
Relevant Posterior Soft Tissues
The hamstring muscles and the insertion of their common head onto the ischial tuberosity are the soft-tissue structures posterior to the hip joint that are important for palpation (▶ Fig. 5.9).
The muscle bellies of the biceps femoris, semimembranosus, and semitendinosus converge proximally and form a common tendon of origin.
Contrary to common belief, the muscle bellies are not aligned along the middle of the proximal femur, but are rather angled in a medial direction. The reason for this angled course is seen in the more medial position of the tuberosity.
Fibers from the tendon of origin (especially the segments of the biceps femoris muscle) sometimes even merge further into the sacrotuberous ligament (Mercer et al., 2005) and can therefore, theoretically, directly influence the SI joint (Woodley, 2005).
The functional importance of this muscle group is viewed far beyond its concentric-dynamic actions (extension of the hip joint, flexion of the knee joint). Proximally, the hamstrings assist other muscles to help control the pelvis in the sagittal plane and prevent the pelvis from tilting down anteriorly. Toward the knee joint, the hamstrings develop their strongest contraction at the end of the swing phase. The muscles decelerate the anterior swing of the leg just before heel strike to prevent excessive loading on the passive structures in the joint.
In hip flexion and extension, the sciatic nerve moves in its course along the lateral tuberosity and the common head. Especially in adduction, it is compressed against neighboring structures. As a result of scar formation after muscle injuries, long periods of sitting, fast running, or exaggerated stretching exercises of the ischiocrural muscles, the nerve can become irritated through friction or stretching (hamstring syndrome; Puranen and Orava, 1991).
Bursae
The course of muscles along bony eminences and edges as well as insertions involves a large number of bursae in a variety of locations. ▶ Fig. 5.10 gives an overview of those that could be of clinical interest in the case of bursitis and are often indirectly palpable. These are the following:
The iliopectineal bursa, lodged between the underside of the iliopsoas nerve and the iliopubic ramus, which protects the muscle against friction where it passes under the inguinal ligament.
Bursae of the greater trochanter—here, under the insertion of the gluteus minimus and medius muscles, there is a subtendinous bursa under each. On the lateral surface, on the boundary with the iliotibial tract, is the trochanteric bursa (Pfirrmann et al., 2001).
The sciatic bursa of the gluteus maximus, located at the inferomedial aspect of the sciatic tuberosity, which reduces friction between the muscle and the tuberosity.
Relevant Lateral Soft Tissues
Tendinosis and bursitis at the greater trochanter are known sources of lateral hip pain (Barratt et al., 2017). The study by Pfirrmann et al. (2001) clarifies the position of the gluteal insertions and bursae (▶ Fig. 5.11).
Seen from posterior to anterior, there is a continuous alternation between bursae and insertions. Each insertion of the gluteus minimus has its own bursa to protect it from friction. The largest bursa covers the posterior facet of the greater trochanter, the distal and lateral portions of the gluteus medius tendon, and the proximal portion of the vastus lateralis origin (Pfirrmann et al., 2001).
5.2 Local Palpation—Lateral
5.2.2 Summary of the Palpatory Process
This palpation involves finding easily accessible structures. It starts by locating and palpating the entire surface of the greater trochanter. The greater trochanter is palpated to provoke pain in locally inflamed soft tissues and to identify one of the most important aspects in the geometry of the proximal femur: the FNA angle.
Starting Position
The patient is in prone position, the arms rest next to the body, and a foot roll can be positioned underneath the ankles. This prone position only needs to be modified for patients suffering from hip joint or lumbar spine symptoms.
To locate boundaries and surfaces of the greater trochanter and to determine the ATA, the knee must be bent for rotational movement of the hip joint. The therapist stands on the contralateral side.
5.2.3 Palpation of Individual Structures
Greater Trochanter
As almost the only directly accessible section of the proximal femur, the greater trochanter acts as an important orientation point in the lateral region of the hip. It is the site of insertion for several small muscles coming from the pelvis, lengthens the lever for the small gluteal muscles, and its palpation allows conclusions regarding the geometry of the femur.
The greater trochanter is naturally found laterally, at around the same level as the tip of the sacrum approximately at the start of the post-anal furrow (see ▶ Fig. 9.32). The trochanter is located approximately 1 hand width inferior to the iliac crest.
Technique
The trochanter is found and recognized in the region described by palpating the area, applying moderate deep pressure, and feeling a hard resistance. With perpendicular palpation, its superior and anterior and posterior borders can be distinctly felt (▶ Fig. 5.12). If the anterior and posterior borders are grasped between thumb and index finger, the width of the trochanter becomes clear (▶ Fig. 5.13). Directly lateral, in the same plane, a large surface of the trochanter can be felt, on which the small gluteus muscles insert, protected by a few bursae.
As this region is often obese, palpation may be difficult and it may be necessary to confirm the location using the following aid.
The therapist flexes the ipsilateral knee and uses the leg as a lever to alternately medially and laterally rotate the hip joint. The trochanter then rolls back and forth underneath the palpating finger so that both its lateral surface and its superior aspect can be easily palpated.
This is the starting point of the dorsal palpation that will follow.
Femoral Neck Anteversion Angle
The FNA angle helps determine the amount of medial rotation at the hip joint. The larger the angle is, the greater the ability of the hip joint to medially rotate—providing the soft tissues (capsule and muscles) have normal elasticity.
In children with cerebral palsy, the angle is determined before derotation osteotomy. Rapid manual determination of the FNA (also known as the ATA “Antetorsion Angle”) goes back to Drehmann (1909) (Tönnis and Legal, 1984) and is based on estimation or goniometric measurement of the angle at the moment when the most lateral forward curve of the trochanter is palpated (Ruwe et al., 1992). The exactitude of this rapid determination is amazingly high. Ruwe et al. (1992) describe the average difference between the trochanteric eminence angle test and intraoperative measurements to be approximately 4° with an intratester error of 5°. The excellent validity and reliability of this test was confirmed again by Chung et al. (2010).
Technique
The therapist positions the hip in neutral rotation and flexes the knee. The flat hand palpates laterally over the trochanter (▶ Fig. 5.14).
The hip is placed in medial rotation by moving the leg laterally away from the sagittal plane. The therapist should now be able to visualize the greater trochanter moving in a large arc around the head of the femur during the medial rotation movement.
While continuing to palpate, the medial rotation movement is stopped at the position where the trochanter is felt to be most lateral (▶ Fig. 5.15).
