External landmarks and boundaries
The anatomical boundaries of the gluteal region are defined by bony structures and skin folds.
Boundaries of the region:
- Superiorly: iliac crest.
- Inferiorly: gluteal fold.
- Laterally: an imaginary vertical line drawn downward from the anterior superior iliac spine.
- Medially: sacrum and coccyx, located deep within the intergluteal cleft.
The main palpable landmarks are the anterior and posterior superior iliac spines, the iliac crest, the greater trochanter of the femur (trochanter major), and the ischial tuberosity.
Muscles of the gluteal region
The musculature here is organized into three layers. The material details the superficial layer and part of the middle layer.
First (superficial) layer Represented exclusively by the gluteus maximus muscle (m. gluteus maximus). It originates from the iliac crest, thoracolumbar fascia, sacrum, coccyx, and sacrotuberous ligament. The fibers run obliquely downward and laterally. The anterosuperior bundles intertwine with the fascia lata (forming the iliotibial tract), while the main bulk attaches to the gluteal tuberosity of the femur.
Second (middle) layer (partial)
- Gluteus medius muscle (m. gluteus medius). Originates from the external surface of the ilium (partially covered by the gluteus maximus), attaching to the greater trochanter.
- Piriformis muscle (m. piriformis). Originates from the pelvic surface of the sacrum, emerges through the greater sciatic foramen, and attaches to the greater trochanter. It divides the sciatic foramen into supra- and infrapiriform spaces.
- Superior gemellus muscle (m. gemellus superior). Located inferior to the piriformis, originating from the ischial spine.
Topography of vessels and nerves
Projections of key structures are of paramount practical importance, especially when performing procedures.
- Sciatic nerve (n. ischiadicus) is projected strictly midway between the ischial tuberosity and the apex of the greater trochanter.
- Superior gluteal bundle (artery and nerve) emerges at the border of the upper and middle thirds of the line connecting the posterior superior iliac spine to the greater trochanter.
- Inferior gluteal bundle is projected laterally and inferiorly from the midpoint of the line running from the posterior superior spine to the ischial tuberosity.
Clinical significance: All major neurovascular formations project onto the two medial quadrants and the inferolateral quadrant. Therefore, the safe zone for intramuscular injections is exclusively the superolateral quadrant of the buttock.
Fasciae and fascial spaces
The deep fascia of the region superiorly and medially attaches to the sacrum and iliac crest, and inferiorly transitions into the fascia lata (fascia lata).
Synovial bursae are present in the region to prevent friction. The most significant are:
- Subcutaneous bursa over the greater trochanter (bursa subcutanea trochanterica).
- Trochanteric bursa of the gluteus maximus (bursa trochanterica m. glutei maximi), located between the muscle tendon and the greater trochanter.
Briefly: answers to topical questions
Which muscles form the second (middle) layer of the gluteal region?
The second (middle) layer of the gluteal region is formed by six muscles arranged from superior to inferior. These include:
- Gluteus medius muscle (m. gluteus medius)
- Piriformis muscle (m. piriformis)
- Superior gemellus muscle (m. gemellus superior)
- Obturator internus muscle (m. obturatorius internus) — represented by its tendon
- Inferior gemellus muscle (m. gemellus inferior)
- Quadratus femoris muscle (m. quadratus femoris)
All muscles of this layer are covered by deep fascia, and the piriformis, gemelli, and tendon of the obturator internus run transversely toward the greater trochanter.
Which muscles form the third (deep) layer of the gluteal region?
The third (deep) layer of the gluteal region is formed by two muscles located beneath the structures of the middle layer. This layer includes:
- Gluteus minimus muscle (m. gluteus minimus) — located in the upper part of the region, completely covered by the gluteus medius and situated with it in a closed osteofibrous space.
- Obturator externus muscle (m. obturatorius externus) — located in the lower part, curves inferiorly around the hip joint and courses posteriorly into the gluteal region.
What passes through the suprapiriform foramen?
The superior gluteal neurovascular bundle passes through the suprapiriform foramen. It includes the following anatomical structures:
- Superior gluteal artery (a. glutea superior) — branches off the internal iliac artery and divides into superior and inferior branches.
- Superior gluteal veins (vv. gluteae superiores) — form a venous plexus that covers the corresponding artery.
- Superior gluteal nerve (n. gluteus superior) — lies inferior and lateral to the blood vessels.
Which vessels and nerves emerge through the infrapiriform foramen?
Three neurovascular structures emerge through the infrapiriform foramen into the subgluteal space. From lateral to medial, they are:
- Sciatic nerve (n. ischiadicus) — the largest nerve in the body, lies most laterally.
- Posterior cutaneous nerve of the thigh (n. cutaneus femoris posterior).
- Comitant artery of the sciatic nerve (a. comitans n. ischiadici).
- Inferior gluteal neurovascular bundle — includes the inferior gluteal artery (a. glutea inferior), companion veins, and branches of the inferior gluteal nerve.
- Pudendal neurovascular bundle — includes the internal pudendal vessels (a. et vv. pudendae internae) and the pudendal nerve (n. pudendus), lying most medially.
Which synovial bursae are located in the gluteal region?
The gluteal region contains synovial bursae that facilitate gliding between muscles and adjacent structures. These include:
- Subcutaneous synovial bursa (bursa subcutanea trochanterica) — located superficially over the greater trochanter of the femur.
- Trochanteric bursa of the gluteus maximus (bursa trochanterica m. glutei maximi) — situated between the tendon of the gluteus maximus and the greater trochanter.
- Gluteus medius bursa (subgluteus medius bursa) — located in the region of the attachment of the gluteus medius tendon.
In general, trochanteric bursae lie deep beneath the tendons of the gluteus maximus, medius, and minimus muscles.
What is the innervation of the gluteus maximus muscle?
The gluteus maximus muscle (m. gluteus maximus) is innervated by the inferior gluteal nerve (n. gluteus inferior).
In electromyography, testing of the gluteus maximus muscle is used for differential diagnosis to rule out radiculopathy or plexopathy.
Class and exam questions
Where is the safe zone for gluteal injections and why?
In the upper outer quadrant. There are no major neurovascular bundles here, unlike the other three quadrants where the sciatic nerve and gluteal vessels are projected.
Which muscle divides the greater sciatic foramen?
Piriformis muscle (m. piriformis). It passes through it, dividing the foramen into supra- and infrapiriform compartments.
How is the sciatic nerve projected?
It is projected onto the midpoint of the distance between the apex of the greater trochanter of the femur and the medial margin of the ischial tuberosity.
What else to study on this topic
- Deep muscle layer of the gluteal region
- Contents of the suprapiriform foramen
- Contents of the infrapiriform foramen
- Topography of the lesser sciatic foramen
- Pelvic ligaments (sacrotuberous and sacrospinous)
Master the complete topic in the "Topographic Anatomy" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on the topic "Gluteal Region" and 2,777 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 91 video lessons on the subject
Other topics in the "Lower Limb" section
Free video lessons: topographic anatomyShort lessons with study notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.