Anatomy
The ilium (os ilium) has several palpable bone points. One of these points is the iliac crest (syn. : iliac crest, or lat.
: Crista iliaca) as the upper limit of the ilium. It ends in the anterior superior iliac spine at the front and in the posterior superior iliac spine at the back. The iliac crests serve to stabilize the iliac ring.
Furthermore, the iliac crest is well suited for bone marrow aspiration due to its superficial position. The area below the iliac crest is also called the iliac scoop (ala ossis ilii). The iliac bone is an important starting point for muscles and therefore has three groins for surface enlargement: Labium internum and labium externum (lat. “labia“: lip, “internum”: inside, “externum”: outside) as well as the linea intermedia (lat. “linea”: line, “intermedium”: “middle”).
Function
The iliac crest plays a decisive role in stabilizing the hip joint. Various ligaments attach to the different parts of the iliac crest. At the posterior third of the crista iliaca, the ligamentum iliolumbale connects the iliac crest with the fourth and fifth lumbar vertebrae.
Although this connection reduces the freedom of movement of the sacroiliac joint (Articulatio sacroiliaca), it prevents both iliac blades from moving away from each other. It also improves the transmission of pressure and load to the joint. The Ligamentum sacrotuberale serves to stabilize the sacroiliac joint at the rear by connecting the spina iliaca posterior superior, the sacrum and the ischial tuberosities.
This strong connection prevents the sacrum from tilting backwards. The inguinal ligament (vesalius ligament or inguinal ligament) runs between the anterior superior iliac spina and the pubic tubercle (pubic tubercle). The inguinal ligament represents the lower and anterior limits of the inguinal canal (Canalis inguinalis). Apart from this, the iliac crest is an important point of origin and starting point of various muscles.
Muscle attachment
The iliac crest has several starting points for muscles: The crest itself with its three groins (labium internum, linea intermedia and labium externum) and the anterior and posterior tip of the crest (spina iliaca anterior superior and spina iliaca posterior superior). The M. obliquus externus abdominis is attached to the labium externum of the crista iliaca. Similarly, the obliquus internus abdominis is applied to the labium internum and the intermedia line.
The M. musculus transversus abdominis also attaches to the linea intermedia of the crista iliaca. The spina iliaca anterior superior serves as the point of origin of the tensor fascia latae, which becomes active during internal rotation and flexion of the thigh (femur). This muscle is often more pronounced in sprinters.
The M. sartorius (tailor muscle) also has the spina iliaca anterior superior as its origin. The M. gluteus maximus (large gluteus muscle) is the most important hip joint extensor and is attached to the spina iliaca posterior superior. Pain in the region of the iliac crest can have various causes.
In the event of a fall or trauma, there is the possibility that the iliac bone or iliac crest may be bruised or even torn. In such cases, severe pain occurs especially when walking. A doctor should be consulted to make a diagnosis.
In order to secure the diagnosis, an X-ray should then be taken. Another possible cause of pain in the region of the iliac crest is a pulled abdominal muscle. This is an overstretching of the sarcomeres, i.e. the smallest functional units of a muscle, the abdominal muscles (M. obliquus internus abdominis, M. transversus abdominis, M. obliquus externus abdominis).
In most cases, muscle strains are the result of muscle overload due to inadequate (wrong or too strong) movements or a lack of or insufficient pre-stretching. Such injuries often occur in connection with sports such as football or during more intensive running or sprinting sessions. The pain is often localised in the iliac crest and can radiate to the navel.
A doctor should be consulted if abdominal muscle strains are suspected. In addition to a physical examination, imaging (magnetic resonance imaging) can also be useful. Physiotherapy should be used as a supplement to adequate pain medication.
