Gluteal Region Muscles PDF

Gluteal Region CHAPTER3 ILO's: By the end of the lectures, the student should be able to: Describe the origin, insertion, action, nerve supply and relations of the muscles of the gluteal region (tensor fascia lata, three...

Gluteal Region CHAPTER3 ILO's: By the end of the lectures, the student should be able to: Describe the origin, insertion, action, nerve supply and relations of the muscles of the gluteal region (tensor fascia lata, three glutei, six lateral rotators). Define the role of the gluteal muscles in walking and the effect of their paralysis. Describe the origin, termination, and branches (or tributaries) of the gluteal vessels and nerves. Describe the site, formation and branches of the sacral plexus. Describe the origin, termination, relations, branches and surface anatomy of the sciatic nerve. Define the injury of the sciatic nerve in the gluteal region. Describe the site and attachments of the sacrotuberous and sacrospinous ligaments. Define the greater and lesser sciatic foramina (boundaries and structures passing through). Identify the muscles, vessels, and nerves of the gluteal region. Identify the structures passing through the greater and lesser sciatic foramina. THE GLUTEAL REGION It is bounded superiorly by the iliac crest, inferiorly by the gluteal fold, postero-medially by the natal cleft and antero-laterally by a line drawn from the anterior superior iliac spine to the greater trochanter Fig.(46). Muscles of the Gluteal Region outer lip iliac weet 1 nollo superior gluteal 1-Tensor fascia lata nerve EX (Fig. 47) EXCEPT glutens maximus Origin : from the outer lip of the iliac crest between the anterior superior - Origin: iliac spine and the iliac tubercle. - Insertion Insertion:: into the anterior border of the ilio-tibial tract. - Nerve supply: superior gluteal nerve. Action: It tightens the ilia-tibial tract to assist in keeping the knee extended in standing and walking. - Abduction T medial rotation - ilio libial trach  Gluteal Region 2- Gluteus maximus (Figs.48 &49) It is the largest muscle in the body. Origin : from - Origin: 1- The outer gluteal surface of the ilium, behind the posterior gluteal line. 2- The posterior surface of sacrum and coccyx. 3- The back of the sacra-tuberous ligament. Insertion: the fibers pass downwards and laterally. - Insertion: Its superficial 3/4: inserted into the posterior border of the upper part of the ilia-tibial tract. Its deep 1/4: inserted into the floor of the gluteal tuberosity. - Nerve supply: inferior gluteal nerve. - Action: 1. It is the main extensor of the hip joint as during rising from sitting position. 2. Lateral rotator and abductor of the hip joint. 3. It tightens the ilia-tibial tract to assist in keeping the knee extended in standing.. N.B.: - The great thickness of the gluteus maximus muscle makes it ideal for intramuscular injections. To avoid injury to the underlying sciatic nerve, the injection should be given on the upper outer quadrant of the buttock. Structures deep to the gluteus maximus: (Fig. 50): 1. Bony prominences: greater trochanter and ischial tuberosity. 2. Ligaments: sacro-spinous and sacra-tuberous. 3. Muscles and tendons: Muscles attached to the greater trochanter: gluteus medius, piriformis, tendon of obturator internus , 2 gemelli and quadratus femoris. Muscles attached to ischial tuberosity: adductor magnus and origin of hamstring muscles. 4. Vessels: Superior and inferior gluteal vessels and internal pudenda/ vessels. 5. Nerves: Superior and inferior gluteal nerves, sciatic nerve, posterior cutaneous nerve of thigh and nerve to quadratus femoris. 6. Bursae: On greater trochanter, ischial tuberosity and vastus /ateralis.  Gluteal Region Sup. gluteal a. and n. lnf. gluteal a. and n. a. andn. N. to obturator intemus Post. Cutaneous n. I of thigh Sciatic nerve / M Fig. (50): Structures p.assing through the sciatic foramina (Deep to the gluteus maximus) 3- Gluteus medius (Fig. 49) steral sufact Origin : from the outer surface of the ilium - Origin: [between iliac crest(above), posterior gluteal line (behind) and anterior gluteal line (below)]. Insertion: Inserted into the oblique ridge on the lateral surface of the - Insertion: greater trochanter. - Nerve supply: superior gluteal nerve.  Gluteal Region & 4- Gluteus minimus (Fig. 49) e anterior suc ↳ It lies deep to the gluteus medius. - Origin: from the outer surface of the ilium between the anterior and inferior gluteal lines. - Insertion: inserted into the anterior surface of the greater trochanter. - Nerve supply: superior gluteal nerve. - Action of gluteus medius and minimus: 1. Abduction of the hip joint. 2. Medial rotation of the thigh (the anterior fibers). 3. Both muscles prevent sagging of the pelvis when the opposite leg is off the ground. N.B: - In paralysis of both muscles on one side: the patient shows a limping gait. - On both sides: the patient shows a waddling gait. Formative Assessment M.C.Q's 1- The powerful extension of the thigh, required when one is standing from a sitting position, is a function of the: a) Gluteus maximus muscle. b) Psoas major muscle. c) lliacus muscle. d) Obturator extermus muscle. 2- A significant weakness in abduction of the thigh would involve the following muscle: a) Gluteus medius. b) Pectineus. c) Gracilis. d) Adductor magnus.  Gluteal Region The Six Lateral Rotators of the Hip Joint (Figs. 50& 51) 1. Piriformis Origin : from the front of the middle three sacral vertebrae in the pelvis; - Origin: then it leaves the pelvis through the greater sciatic foramen to enter the gluteal region. - Insertion Insertion:: inserted into the tip of the greater trochanter. - Nerve supply: branches from the sacral plexus (S1' 2). - Action:lateral rotation of the thigh at the hip joint. 2- Obturator internus - Origin: From the pelvic surface of the obturator membrane. From the margins of the obturator foramen. From an area extending between obturator foramen and greater sciatic notch. - Insertion: Its tendon passes through the lesser sciatic foramen laterally across the back of hip joint to be joined by the two gemelli (superior and inferior) to form a common tendon. It is inserted into the medial surface of the greater trochanter.. Nerve supply: nerve to obturator internus from the sacral plexus (Ls, S1,2).. Action: Lateral rotation of the thigh at the hip joint.  Gluteal Region 3. Superior gemellus - Origin: from the upper margin of the lesser sciatic notch. - Insertion: into the upper border of the tendon of, obturator internus. - Nerve supply: nerve to obturator internus (from the sacral plexus). - Action: lateral rotation of the hip joint. I 4. Inferior gemellus - Origin: from the lower margin of the lesser sciatic notch. - Insertion: into the lower border of the tendon of obturator internus. - Nerve supply: nerve to quadratus femoris (from the sacral plexus). - Action: lateral rotation of the hip joint. 5- Quadratus femoris - Origin: from lateral margin of ischial tuberosity. - Insertion: into the quadrate tubercle. - Nerve supply: nerve to quadratus femoris. - Action: lateral rotation of the thigh at the hip joint. I 6- Obturator externus (Fig. 52) Origin: from outer surface of obturator membrane and from margins of obturator fora men. Insertion: The tendon passes below then behind the hip joint to become inserted into the floor of the trochanteric fossa. Nerve supply: posterior division of obturator nerve (from lumbar plexus). Action: lateral rotation of the thigh at the hip joint.