1. Muscles of the Gluteal Region
DR. NIVIN SHARAF MD
LMCC

2. Objectives
Identify the bony landmarks of the pelvis and hip on the articulated skeleton and bones. Include: pelvis (ilium, ischium, pubis, iliac crest, iliac fossa, anterior superior iliac spines, pubic tubercle, pubic crest, acetabulum, obturator foramen, greater and lesser sciatic notches, ischial spine, sacroiliac joint, greater and lesser sciatic foramina, ischial tuberosity), femur (head, neck, shaft, greater and lesser trochanters, intertrochanteric line and crest, linea aspera).
Explain how the anatomical position affects the muscle function. .
Locate the piriformis muscle and the suprapiriform and the infrapiriform spaces.
Identify the superior gluteal nerve in the suprapiriform space and the sciatic and inferior gluteal nerves emerging via infrapiriform space.
. Summarize the muscles of gluteal region and thigh in terms of their location, origin, insertion, nerve supply and actions.
. Summarize the muscles of gluteal region and thigh in terms of their
location, origin, insertion, nerve supply and actions.

3. Bony Skeleton GENERAL INTRODUCTION Body_ID: HC006002 Body_ID: P006002
Body_ID: HC006002
Body_ID: P006002
Body_ID: F006001
Figure 6.1 Upper margin of the lower limb.
The lower limb is directly anchored to the axial skeleton by a sacroiliac joint and by strong ligaments, which link the pelvic bone to the sacrum. It is separated from the abdomen, back, and perineum by a continuous line (Fig. 6.1), which:
joins the pubic tubercle with the anterior superior iliac spine (position of the inguinal ligament) and then continues along the iliac crest to the posterior superior iliac spine to separate the lower limb from the anterior and lateral abdominal walls;
passes between the posterior superior iliac spine and along the dorsolateral surface of the sacrum to the coccyx to separate the lower limb from the muscles of the back;
joins the medial margin of the sacrotuberous ligament, the ischial tuberosity, the ischiopubic ramus, and the pubic symphysis to separate the lower limb from the perineum.
Body_ID: P006001
The lower limb is divided into the gluteal region, thigh, leg, and foot on the basis of major joints, component bones, and superficial landmarks (Fig. 6.2):
the gluteal region is posterolateral and between the iliac crest and the fold of skin (gluteal fold) that defines the lower limit of the buttocks;
anteriorly, the thigh is between the inguinal ligament and the knee joint-the hip joint is just inferior to the middle third of the inguinal ligament and the posterior thigh is between the gluteal fold and the knee;
the leg is between the knee and ankle joint;
the foot is distal to the ankle joint.
The femoral triangle is a pyramid-shaped depression formed by muscles in the proximal regions of the thigh and by the inguinal ligament, which forms the base of the triangle. The major blood supply and one of the nerves of the limb (femoral nerve) enter into the thigh from the abdomen by passing under the inguinal ligament and into the femoral triangle.
Body_ID: P006005
The popliteal fossa is posterior to the knee joint and is a diamond-shaped region formed by muscles of the thigh and leg. Major vessels and nerves pass between the thigh and leg through the popliteal fossa.
Body_ID: P006006
Most nerves, vessels and flexor tendons that pass between the leg and foot pass through a series of canals (collectively termed the tarsal tunnel) on the posteromedial side of the ankle. The canals are formed by adjacent bones and a flexor retinaculum, which holds the tendons in position.

5. FYI

6. FEMUR Posterior. Anterior. greater trochanter head intertrochanteric
Proximal:
-head,
-fovea
-neck,
-greater + lesser
trochanters,
-intertrochanteric
line + crest
-gluteal
tuberosity
-linea aspera.
Distal:
-supracondylar
lines
-epicondyles,
-condyles
-adductor
tubercle
head
intertrochanteric
crest
neck
lesser
trochanter
intertrochanteric
line
gluteal tuberosty
linea aspera
medial
epicondyle
lateral
epicondyle
adductor
tubercle
supracondylar
lines
lateral
condyle
medial
condyle

7. Sciatic foramen
Seven nerves enter the gluteal region from the pelvis through the greater sciatic foramen (Fig. 6.47A): the superior gluteal nerve, sciatic nerve, nerve to the quadratus femoris, nerve to the obturator internus, posterior cutaneous nerve of the thigh, pudendal nerve, and inferior gluteal nerve. Body_ID: P An additional nerve, the perforating cutaneous nerve, enters the gluteal region by passing directly through the sacrotuberous ligament.
Some of these nerves, such as the sciatic and pudendal nerves, pass through the gluteal region en route to other areas. Nerves such as the superior and inferior gluteal nerves innervate structures in the gluteal region. Many of the nerves in the gluteal region are in the plane between the superficial and deep groups of muscles

8. Movements of Hip Joint
Internal rotation
External
rotation

9. Gluteal region Gluteal muscles: a-Gluteus maximus b-Gluteus medius
c-Gluteus minimus
Tensor fasciae latae -iliotibial tract.
Small lateral rotators of thigh.
Sciatic and posterior cutaneous nerve of thigh.
Superior and inferior gluteal ARTERIES.
The gluteal region lies posterolateral to the bony pelvis and proximal end of the femur (Fig. 6.43). Muscles in the region mainly abduct, extend, and laterally rotate the femur relative to the pelvic bone. Body_ID: P The gluteal region communicates anteromedially with the pelvic cavity and perineum through the greater and lesser sciatic foramina, respectively. Inferiorly, it is continuous with the posterior thigh. Body_ID: P The sciatic nerve enters the lower limb from the pelvic cavity by passing through the greater sciatic foramen and descending through the gluteal region into the posterior thigh and then into the leg and foot. Body_ID: P The pudendal nerve and internal pudendal vessels pass between the pelvic cavity and perineum by passing first through the greater sciatic foramen to enter the gluteal region and then immediately pass through the lesser sciatic foramen to enter the perineum. The nerve to the obturator internus and gemellus superior follows a similar course. Other nerves and vessels that pass through the greater sciatic foramen from the pelvic cavity supply structures in the gluteal region itself.

11. Gluteus Maximus Gluteal region: -Gluteus maximus
iliotibial tract
Tensor
Fasciae
Latae
Gluteus
maximus
gluteus maximus
Gluteal region:
-Gluteus maximus
(most powerful extensor,
also lateral rotator)
Insertion:
Gluteal tuberosity +
Iliotibial tract (band)
Lateral View
Posterior View

12. Gluteus Maximus
a more superficial group of larger muscles, which mainly abduct and extend the hip and include the gluteus minimus, gluteus medius, and gluteus maximus-an additional muscle in this group, the tensor fasciae latae, stabilizes the knee in extension by acting on a specialized longitudinal band of deep fascia (the iliotibial tract) that passes down the lateral side of the thigh to attach to the proximal end of the tibia in the leg.
FYI
Gluteus Maximus and Tensor Fascia Lata insert into Iliotibial Tract
- Iliotibial tract is a thickening of the deep fascia (fascia lata) that extends from the ilium to the tibia.
- Tension from contraction of gluteus maximus and tensor fasciae latae stabilizes the lower limb as a weight-bearing column.

13. Tensor Fascia Lata
Lateral
Posterior

14. Illio Tibial Tract (Band)
Is the thickened lateral part of fascia latae.
Receive insertions of:
1- tensor fasciae l.
2- superf ¾ of gluteus maximus.
Attached to oblique ridge on the front of lat condyle of tibia.
Stabilize femur on tibia during standing.

15. Gluteus Medius
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Extends, Abducts and Medial and Lateral rotations (Ant and posterior fibers)
helps to keep the pelvis level when the opposite leg is raised during activities such as running,
Walking, or standing on one leg

16. Gluteus Minimus Posterior View Small Lateral Rotators of Thigh
Piriformis .
Obturator internus.
Superior gemillus
inferior gemillus
Quadratus femoris.

17. Action Gluteus maximus:1- main extensor of hip.
2- lateral rotation of hip
3- Maintain knee joint in Extension through the iliotibial tract.
gluteus medius, gluteus minimus, tensor fascia latae :
1- extension of hip
2- abduction of hip
3-medial rotation (anterior fibers)
4-contract during walking to prevent tilting of pelvis.

18. Nerve supply Inferior gluteal nerve → gluteus maximus.
Superior gluteal nerve →gluteus medius.
gluteus minimus.
tensor fascia latae

19. Intrinsic muscles
Infra and supra Piriformis space

20. Superior gluteal nerve

21. Lateral and Medial Rotation of the hip
gluteus medius
gluteus
maximus
gluteus minimus
Deep to gluteus maximus:
-abductors:
gluteus medius
gluteus minimus
(anterior fibres medially rotate)
-lateral (external) rotators:
piriformis
obturator internus
(associated gemelli)
quadratus femoris
[obturator externus is also a
lateral rotator]
piriformis
superior
gamellus
obturator
internus
quadratus
femoris
inferior
gamellus

22. Gluteus medius and minimus: abduction of femur and stabilization of pelvis

23. * Normal Positive sign Trendelenburg Sign. Loss of abductor function
(gluteus medius & minimus)
causes the pelvis to tilt down
when supporting the body
on the affected side (*).
(I.e. damage to superior
gluteal nerve).
This function of these
muscles is called
“stabilization of the pelvis”. *

24. Superior and Inferior Gluteal Nerves
Gluteu Medius
Gluteus Minimus
Inferior
Gluteus Maximus

25. QUIZ
QUIZ

26. Intragluteal Injections
What?
Why?

27. Avoid Sciatic Nerve Injury

28. Sciatic Nerve (L4-S3) Thickest nerve in the body About 2cm in diameter
L4, L5, S1, S2, and S3 Inside the pelvis
Leave through greater sciatic Foramen, below piriformis.

29. FYI!

30. Sciatic Nerve Variations!

31. Action N supply Insertion Origin Muscle Lateral rotation S1,2
Upp border of g trochanter
3 middle
Sacral peices
Piriformis
N to obturator int
T of obt. int
Spine of ischium
Sup gemillus
N to quadratus f
Upp margin of ischial tuberosity.
Inf gemillus
Med surf of g trochanter
Obturator
Membrane
Obturator internus
Quadrate t
Ischial tuber
Quad fem

32. QUIZ

34. References www.netteranatomy.com www.studentconsult.com www.google.com
Gray’s Anatomy for students