Muscles of the Pelvis, Leg and Foot Lab 21 Muscles of the Pelvis, Leg and Foot

Muscles to know psoas major iliacus gluteus maximus gluteus medius sartorius quadriceps femoris (4) gracilus adductor longus biceps femoris semitendinosis semimembranosus tibialis anterior ext hallucis longus ext digitorum longus fibularis (peroneus) longus gastrocnemius soleus flexor hallucis longus flexor digitorum longus

Muscles of the Pelvis and Lower Limbs Pelvic girdle is tightly bound to axial skeleton: permits little movement has few muscles

Muscles that Position the Lower Limbs Muscles that move the thigh Muscles that move the leg Muscles that move the foot and toes

Generally… Muscles that are lateral are abductors Muscles that are medial are adductors flexors are on inner surface of joint extensors are on outer surface of joint Note: in legs and feet, look at each joint individually (cf. arms)

Muscles that Move the Thigh Gluteal muscles Lateral rotators Adductors Iliopsoas group

Muscles of hip and thigh psoas major iliacus gluteus maximus gluteus medius adductor longus

Gluteal Muscles (1 of 2) Cover lateral surfaces of ilia Gluteus maximus: largest, most posterior gluteal muscle produces extension and lateral rotation at hip Originates on illiac crest, etc., inserts on illiotibial tract and femur

Gluteal Muscles (2 of 2) Gluteus medius and [gluteus minimus]: originate anterior to gluteus maximus insert on trochanter of femur

Muscles that Move the Thigh Figure 11–19a, b

Muscles that Move the Thigh Figure 11–19c, d

Adductors Adductor longus: Gracilis (UPPER LEG): hip flexion and adduction Gracilis (UPPER LEG):

Iliopsoas group 2 hip flexors insert on the same tendon: psoas major originates on lumbar vetebrae, inserts on femur iliacus originates on illium/fossa

Summary: Muscles that Move the Thigh Table 11–16 (1 of 2)

Summary: Muscles that Move the Thigh Table 11–16 (2 of 2)

Muscles that Move the Leg Flexors of the knee: originate on the pelvic girdle generally: hamstrings Extensors of the knee: originate on the femoral surface insert on the patella generally: quads

Flexors of the Knee Biceps femoris Semimembranosus Semitendinosus Sartorius: originates superior to the acetabulum long, ribbon-like muscle traverses the quads and wraps around to the back of the knee

Hamstrings Made up of: All are knee flexors biceps femoris (long and short heads) semimembranosus semitendinosus All are knee flexors

Muscles that Move the Leg Figure 11–20a

Extensors of the Knee 4 muscles of the quadriceps femoris: 3 vastus muscles: vastus lateralis vastus medialis vastus intermedius rectus femoris muscle

Muscles that Move the Leg Figure 11–20b, c

Summary: Muscles that Move the Leg Table 11–17 (1 of 2)

Summary: Muscles that Move the Leg Table 11–17 (2 of 2)

Muscles that Move the Foot and Toes Extrinsic muscles that move the foot and toes include: muscles that produce extension at the ankle (Plantar flexion) muscles that produce flexion at the ankle muscles that produce extension at the toes muscles that produce flexion at the toes

Muscles that Produce Extension at the Ankle (Plantar flexion) Calf muscles Large posterior calf muscles, both insert on Achilles): Gastrocnemius Soleus Fibularis longus

Muscles that Move the Foot and Toes Figure 11–21a, b

Muscles that Move the Foot and Toes Figure 11–21c, d

The Achilles Tendon The calcaneal tendon (Achilles tendon): shared by the gastrocnemius and soleus

Muscles that Produce Flexion at the Ankle Tibialis anterior: opposes the gastrocnemius

Muscles that Move the Foot and Toes Figure 11–21a, b

Muscles that Move the Foot and Toes Figure 11–21c, d

Muscles that Produce Extension at the Toes Extensor digitorum longus Extensor hallucis longus Toe extensors are on top of foot Note: there are no muscles in toes themselves (only tendons)

The Intrinsic Muscles of the Foot Figure 11–22a

Muscles that Produce Flexion at the Toes Flexor digitorum longus Flexor hallucis longus: oppose the extensors Toe flexors are on bottom of foot

The Intrinsic Muscles of the Foot Figure 11–22b, c

Summary: Muscles that Move the Foot and Toes Table 11–18

Today Lab 21 Ignore muscles that are not on the list Due Next Week