Muscular System Part D Prepared by Alexander Cheroske and W. Rose. HESC310 11/15/2018 Muscular System Part D Prepared by Alexander Cheroske and W. Rose. Some figures from Martini et al., Visual A&P, and Marieb & Hoehn, Human Anat. & Physiol.. Muscles labelled in light gray are not on “Muscles_to_know.html” and will not be on test. Portions copyright Pearson Education Axial Skeleton

Muscles that move the thigh Originate on pelvis & associated ligaments & fascia Iliac crest Sacrum Gluteus medius (cut) Gluteal Group Gluteus medius Gluteus maximus (cut) Gluteus maximus Gluteus minimus Tensor fasciae latae Iliotibial tract Figure 10.16.1-2 The muscles that move the thigh originate on the pelvis and associated ligaments and fasciae Gluteal muscles, posterior view Lateral view of the gluteal region Figure 10.16 1 – 2 2

Muscles that move the thigh Originate on pelvis & associated ligaments & fascia Gluteal Group Iliopsoas Group An anterior view showing the isolated iliopsoas muscle group and the adductor group Gluteus maximus (cut) Gluteus medius (cut) Gluteus minimus Tensor fasciae latae Psoas major Iliacus L5 Lateral Rotator Group Inguinal ligament Piriformis Adductor Group Superior gemellus Obturator internus Pectineus Obturator externus Adductor brevis Inferior gemellus Adductor longus Quadratus femoris Adductor magnus Figure 10.16.3-4 The muscles that move the thigh originate on the pelvis and associated ligaments and fasciae Gracilis Ischial tuberosity Iliotibial tract A lateral view of a dissection of the gluteal region Figure 10.16 3 – 4 4

Knee flexors: hamstrings Knee extensors: quadriceps femoris Muscles that move the leg Anterior superior iliac spine Originate on pelvis & femur Iliac crest Inguinal ligament Gluteus medius Iliacus Tensor fasciae latae Iliopsoas Psoas major Pubic tubercle Tensor fasciae latae Gluteus maximus Pectineus Adductor longus Gracilis Adductor magnus Sartorius Gracilis Extensors of the Knee (Quadriceps muscles) Iliotibial tract Rectus femoris Vastus intermedius (lies deep to the rectus femoris and vastus lateralis) SM BF Flexors of the Knee ST Biceps femoris Vastus lateralis SM+ ST+BF=hamstrings. SM+ST=med ham. BF=lat ham. ST, SM, & BF long head originate on post ischium. BF short head from post femur. Longer distal tendon on ST compared to SM, hence the name. Distally, belly of SM medial to belly of ST. Figure 10.17.1-2 The muscles that move the leg originate on the pelvis and femur Semitendinosus Vastus medialis Quadriceps tendon Semimembranosus Sartorius Patella Popliteus Patellar ligament Knee flexors: hamstrings & popliteus Knee extensors: quadriceps femoris Figure 10.17 1 – 2 5

[Right thigh posterior views.] HESC310 11/15/2018 Figure 1.  Drawings illustrate the three muscles in the posterior compartment of the thigh that together constitute the hamstring muscle complex. The short head of the biceps femoris muscle is deep to the long head. The tendinous nature of the semitendinosus muscle inferiorly is appreciated, as is its raphe. The origin of the semimembranosus muscle is noted to be superolateral to the conjoint tendon. [Right thigh posterior views.] Hamstring Muscle Complex: An Imaging Review. Koulouris G, Connell D. RadioGraphics 25: 571-586, 2005. http://radiographics.rsna.org/content/25/3/571.long. Good review of normal hamstring anatomy and function in gait, followed by review of injuries and imaging – mostly MRI with some ultrasound. Axial Skeleton

Muscles that move the leg Thigh cross section POSTERIOR Semitendinosus Semimembranosus Sciatic nerve Adductor magnus Biceps femoris Gracilis MEDIAL Adductor longus Vastus lateralis Great saphenous vein Vastus intermedius Sartorius Femur Vastus medialis Rectus femoris Figure 10.17.4 The muscles that move the leg originate on the pelvis and femur ANTERIOR Figure 10.17 4 8

Tendon of flexor digitorum Muscles that move foot and toes Multiple muscle layers in posterior leg Superficial Dissection Deep Dissection Ankle Extensors Plantaris Head of fibula Gastrocnemius Popliteus Ankle Extensors (Deep) Soleus Tibialis posterior Fibularis longus Fibularis brevis Digital Flexors Gastrocnemius (cut and removed) Flexor digitorum longus Figure 10.18.1 The extrinsic muscles that move the foot and toes originate on the tibia and fibula Flexor hallucis longus Tendon of flexor digitorum longus Calcaneal tendon Tendon of fibularis brevis Calcaneus Tendon of fibularis longus Figure 10.18 1 9

Muscles that move foot and toes Lateral View Medial View Iliotibial tract Patella Medial surface of tibial shaft Head of fibula Patellar ligament Ankle Extensors Gastrocnemius Ankle Flexors Ankle Extensors Fibularis longus Tibialis anterior Gastrocnemius Soleus Soleus Fibularis brevis Digital Extensors Tibialis posterior Extensor digitorum longus Superior extensor retinaculum Superior extensor retinaculum Figure 10.18.2-3 The extrinsic muscles that move the foot and toes originate on the tibia and fibula Tendon of extensor hallucis longus Calcaneal tendon Calcaneal tendon Inferior extensor retinaculum Inferior extensor retinaculum Tendon of tibialis anterior Figure 10.18 2 – 3 10

Superior view of foot showing muscles of foot and toes Superior extensor retinaculum Medial malleolus of tibia Lateral malleolus of fibula Tendon of tibialis anterior Inferior extensor retinaculum Intrinsic Muscles of the Foot, Great Toe Tendons of extensor digitorum longus Extensor hallucis brevis Intrinsic Muscles of the Foot, Toes 2–5 Abductor hallucis Dorsal interossei Figure 10.19.1 The intrinsic muscles of the foot originate on the tarsal and metatarsal bones and associated tendons and ligaments Tendon of extensor hallucis longus Tendons of extensor digitorum brevis Figure 10.19 1 11

Clinical Example: 69 y.o. male at E.R. Sx: Stabbing pain & swelling in R leg commenced suddenly, upon standing from sitting position. Hx: At age 13, R Achilles tendon was partially severed. Repair was attempted. R gastrox smaller than L since then, but no pain or loss of mobility until now. Physical exam: Ruptured Achilles tendon suspected. Diagnostic studies: Plain radiographs shows ruptured calcified Achilles tendon. Dx: Ruptured calcified Achilles tendon Wick and Rieger (2008) NEJM 358: 2618

Muscle Actions of the Leg: Summary Leg muscles: Plantar flex and evert the foot (lateral compartment) Plantar flex the foot and flex the toes (posterior compartment) Dorsiflex the foot and extend the toes (anterior compartment)

Muscle Actions of the Leg: Summary Figure 10.24b