The Muscular System: Part D 10 The Muscular System: Part D

General Tip to determine Actions If muscle is on the Anterior Surface of the body, it will move the insertion anteriorly If muscle is on the Posterior Surface … … will move ……posteriorly If muscle … Medial Surface … Medially If muscle … Lateral Surface …Laterally Muscle crosses two joints does actions at both joints Thigh Flexion Leg Extension Anterior Posterior © 2013 Pearson Education, Inc.

I. Muscles Crossing Hip Joint Introduction Muscles crossing both joints: Sartorius, Bracilis, Rectus Femoris, Hamstrings (3) Fascia Lata: connective tissue that wraps around muscle groups. 3 groups are enclosed into compartments Anterior Muscles: flex femur at hip, extend leg at knee Posterior Muscles: extend thigh, flex leg Medial muscles: all adduct thigh Walking A&P Flix™: Muscles that act on the hip joint and femur: An overview PLAY © 2013 Pearson Education, Inc.

A. Thigh flexors pass hip joint anteriorly Introduction … Origins: Type Joint: Actions include: A. Thigh flexors pass hip joint anteriorly 1. Iliopsoas: prime mover of flexion Upper groin muscle of 3 Composed of two muscles w/ same insertion iliacus psoas major Groin Pectineus Adductor longus PLAY A&P Flix™: Anterior muscles that cross the hip joint © 2013 Pearson Education, Inc.

2. Tensor fasciae latae 3. Rectus femoris 4. Sartorius Thigh Flexors … 2. Tensor fasciae latae anterior-lateral Inserts on Illiotibial tract = sheet of dense connective tissue that runs from the Illium to the Tibia laterally Mainly a Synergist 3. Rectus femoris Crosses 2 joints Anterior on femur Part of Quadriceps 4. Sartorius Runs inferiorly from lateral to medial 5. Adductor Group 3 muscles that Also Flex Thigh, but are named after their adduction of the thigh (details later) © 2013 Pearson Education, Inc.

Movements of the Thigh A&P Flix™: Iliopsoas PLAY A&P Flix™: Iliopsoas PLAY A&P Flix™: Tensor fasciae latae PLAY A&P Flix™: Rectus femoris PLAY A&P Flix™: Sartorius © 2013 Pearson Education, Inc.

12th rib Quadratus lumborum Psoas minor Iliac crest Patella Figure 10.20a Anterior and medial muscles promoting movements of the thigh and leg. 12th thoracic vertebra 12th rib Quadratus lumborum Psoas minor Iliac crest Psoas major Iliopsoas Iliacus 5th lumbar vertebra Anterior superior iliac spine Tensor fasciae latae Pectineus Adductor longus Sartorius Gracilis Quadriceps femoris • Rectus femoris Adductor magnus • Vastus lateralis • Vastus medialis Tendon of quadriceps femoris Patella Patellar ligament © 2013 Pearson Education, Inc.

Figure 10.21a Posterior muscles of the right hip and thigh. Gluteus medius Gluteus maximus Adductor magnus Gracilis Iliotibial tract Long head Biceps femoris Short head Hamstrings Semitendinosus Semimembranosus © 2013 Pearson Education, Inc.

Movements of the Thigh A&P Flix™: Biceps femoris PLAY A&P Flix™: Biceps femoris PLAY A&P Flix™: Semitendinosus PLAY A&P Flix™: Semimembranosus © 2013 Pearson Education, Inc.

Movements of the Thigh … B. Thigh extensors Location: Posterior Thigh 1. Gluteus maximus – prime mover of extension. 2. Hamstring muscles – Group of 3 muscles; prime movers Cross 2 Joints Biceps femoris– most lateral Semitendinosus– Has a Long Tendon Lays on top of Semimembranosus Semimembranosus – wide like a membrane; seen on either side of Semitendinosus 3. Adductor Magnus Large muscle w/ posterior portion acting in thigh extension Gluteus Maximus Semimembranosus © 2013 Pearson Education, Inc.

Thigh Extensors … A&P Flix™: Rectus femoris PLAY A&P Flix™: Rectus femoris PLAY A&P Flix™: Vastus lateralis PLAY A&P Flix™: Vastus medialis PLAY A&P Flix™: Vastus intermedius PLAY A&P Flix™: Gluteus maximus(c) PLAY A&P Flix™: Gluteus medius © 2013 Pearson Education, Inc.

C. Muscle that Adduct thigh Adductor Group– on medial surface of upper thigh also medially rotate and flexes thigh Adductor Brevis Deep under Pectineus Adductor Longus Lowest muscle of 3 seen in groin Adductor Magnus Partially Superficial, but deep to Gracilis, Pectineus, Adductor longus and brevis Large muscle with anterior and posterior portions w/ broad insertion. Does antagonistic actions of flex & extend thigh. Cut Pectineus Quadriceps, Sartorius, and Facia L. removed Adductor Magnus PLAY A&P Flix™: Medial muscles that cross the hip joint © 2013 Pearson Education, Inc.

2. Pectineus 3. Gracilis Seen as 2nd muscle in groin superficially Adductors … 2. Pectineus Seen as 2nd muscle in groin superficially Deep to Quadriceps Actions as for A. Longus & Brevis 3. Gracilis Superficial Crosses 2 Joints: so also flexes knee Only adducts at hip joint Adductor Longus Adductor Magnus © 2013 Pearson Education, Inc.

Movements of the Thigh Close File and go to Video “Hip Joint-2” PLAY A&P Flix™: Medial muscles that cross the hip joint © 2013 Pearson Education, Inc.

A&P Flix™: Pectineus Pectineus (cut) O O Adductor Adductor magnus Figure 10.20b Anterior and medial muscles promoting movements of the thigh and leg. Pectineus (cut) O O Adductor brevis Adductor magnus I Adductor longus I I Femur O = origin Ι = insertion PLAY A&P Flix™: Pectineus © 2013 Pearson Education, Inc.

D. Muscles that Move the Thigh Laterally = Thigh Abductors 1. Gluteus medius (also medially rotates thigh) Partially deep to G. maximus 2. Gluteus minimus (also Deep to G. medius 3. Gluteus maximus - Synergist in Abduction Cut end of Gluteus Max. © 2013 Pearson Education, Inc.

Figure 10.21c Posterior muscles of the right hip and thigh. Gluteus medius (cut) Gluteus minimus Superior gemellus Piriformis Obturator internus Obturator externus Inferior gemellus Quadratus femoris Gluteus maximus (cut) © 2013 Pearson Education, Inc.

Movements of the Thigh A&P Flix™: Gluteus maximus(c) PLAY A&P Flix™: Gluteus maximus(c) PLAY A&P Flix™: Gluteus medius © 2013 Pearson Education, Inc.

Figure 10.21b Posterior muscles of the right hip and thigh. External oblique Lumbar fascia Iliac crest Gluteus medius Median sacral crest (of sacrum) Adductor magnus Gluteus maximus Gracilis Iliotibial tract Biceps femoris Semitendinosus Semimembranosus © 2013 Pearson Education, Inc.

Summary of Movement at the Hip Joint VIDEO WORKS PLAY A&P Flix™: Movement at the hip joint © 2013 Pearson Education, Inc.