Identifying Muscles of the Lower Extremities - Anatomy
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What is the primary action of the sartorius?
What is the primary action of the sartorius?
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The sartorius originates from the anterior superior iliac spine (ASIS) and inserts near the tibial tuberocity, running laterally to medially along the anterior thigh. Because the sartorius crosses both the hip and the knee, contraction of the muscle is capable of flexing both the leg and thigh. By running laterally to medially, shortening of the muscle also causes lateral rotation and abduction of the thigh.
The sartorius originates from the anterior superior iliac spine (ASIS) and inserts near the tibial tuberocity, running laterally to medially along the anterior thigh. Because the sartorius crosses both the hip and the knee, contraction of the muscle is capable of flexing both the leg and thigh. By running laterally to medially, shortening of the muscle also causes lateral rotation and abduction of the thigh.
Which muscle does NOT extend the knee?
Which muscle does NOT extend the knee?
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The quadriceps muscle group is primarily responsible for the extension of the knee. This group includes the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. The biceps femoris part of the hamstring muscle group and is responsible for the flexion of the knee.
The quadriceps muscle group is primarily responsible for the extension of the knee. This group includes the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. The biceps femoris part of the hamstring muscle group and is responsible for the flexion of the knee.
Which of the following muscles is not part of the pes anserine group?
Which of the following muscles is not part of the pes anserine group?
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The semitendinosus, gracilis, and sartorius are the three muscles that make up the pes anserine group, coming from the posterior, medial, and anterior compartments of the thigh, respectively. The adductor longus, is not part of this group as it inserts on the linea aspera of the femur, rather than the pes anserinus, like the semitendinosus, gracilis, and sartorius.
The semitendinosus, gracilis, and sartorius are the three muscles that make up the pes anserine group, coming from the posterior, medial, and anterior compartments of the thigh, respectively. The adductor longus, is not part of this group as it inserts on the linea aspera of the femur, rather than the pes anserinus, like the semitendinosus, gracilis, and sartorius.
How many muscles attach to the talus?
How many muscles attach to the talus?
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No muscles attach to the talus directly. However, the extensor digitorum brevis comes close, via its attachment to one of the talocalcaneal ligaments.
No muscles attach to the talus directly. However, the extensor digitorum brevis comes close, via its attachment to one of the talocalcaneal ligaments.
To which bone does the largest tendon in the body insert?
To which bone does the largest tendon in the body insert?
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The achilles tendon or calcaneal tendon inserts on the posterior side of the calcaneus. It is the largest tendon in the body and pulls the heel up to point the toes downward. This decreases the angle between the bottom of the foot and back of the leg. This is called plantar flexion.
The achilles tendon or calcaneal tendon inserts on the posterior side of the calcaneus. It is the largest tendon in the body and pulls the heel up to point the toes downward. This decreases the angle between the bottom of the foot and back of the leg. This is called plantar flexion.
Which muscle inserts at the calcaneus and originates on the fibula and the medial border of the tibia.
Which muscle inserts at the calcaneus and originates on the fibula and the medial border of the tibia.
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The soleus is the correct answer. The gastrocnemius also inserts on the calcaneus, but it originates on the condyles of the femur. Th plantaris muscle also inserts at the calcaneus, but it also originates at the femur. The biceps femoris muscles are located on the posterior side of the thigh. The sartorius originates on the anterior superior iliac spine, and inserts on the anteromedial aspect of the tibia.
The soleus is the correct answer. The gastrocnemius also inserts on the calcaneus, but it originates on the condyles of the femur. Th plantaris muscle also inserts at the calcaneus, but it also originates at the femur. The biceps femoris muscles are located on the posterior side of the thigh. The sartorius originates on the anterior superior iliac spine, and inserts on the anteromedial aspect of the tibia.
Which of the following muscles is not located in the posterior compartment of the thigh?
Which of the following muscles is not located in the posterior compartment of the thigh?
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We are looking for a muscle in the posterior compartment of the thigh. This means that the muscle will be on the back of the leg, between the pelvis and the kneecap. The correct answer is the gracilis muscle, which unlike the other three is located in the anterior compartment of the thigh.
We are looking for a muscle in the posterior compartment of the thigh. This means that the muscle will be on the back of the leg, between the pelvis and the kneecap. The correct answer is the gracilis muscle, which unlike the other three is located in the anterior compartment of the thigh.
Which muscle running along the plantar surface of the foot is responsible for much of the "spring" or "push off" force when walking or running?
Which muscle running along the plantar surface of the foot is responsible for much of the "spring" or "push off" force when walking or running?
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The flexor hallucis longus attaches to the plantar surface of the hallux or big toe. Much of the spring force (originating in the foot) when walking or running is generated by the contraction of this muscle. The popliteus and gastrocnemius muscles are in the crural region. The flexor digitorum longus is also in the foot, but acts to flex the second, third, fourth, and fifth toes which generate less push force.
The flexor hallucis longus attaches to the plantar surface of the hallux or big toe. Much of the spring force (originating in the foot) when walking or running is generated by the contraction of this muscle. The popliteus and gastrocnemius muscles are in the crural region. The flexor digitorum longus is also in the foot, but acts to flex the second, third, fourth, and fifth toes which generate less push force.
Which muscle functions to depress the base of the first metatarsal during gait?
Which muscle functions to depress the base of the first metatarsal during gait?
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The fibularis (peroneus) longus depresses the base of the first metatarsal, allowing the body to advance forward, over the limb that is in contact with the ground (the stance limb).
The fibularis (peroneus) longus depresses the base of the first metatarsal, allowing the body to advance forward, over the limb that is in contact with the ground (the stance limb).
Which of the following is not considered part of the quadriceps muscle group?
Which of the following is not considered part of the quadriceps muscle group?
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The quadriceps muscle group consists of four different regions, each with a different origin. The rectus femoris originates on the anterior inferior iliac spine (AIIS). The vastus lateralis originates from the greater trochanter of the femur. The vastus medialis originates from the intertrochanteric line. The vastus intermedius originates from the shaft of the femur. Together, the muscles of the quadriceps work to extend the leg by straightening the knee.
The biceps femoris is located posterior to the femur, and is a part of the hamstring muscle group. The primary action of the biceps femoris is flexion of the leg by bending the knee.
The quadriceps muscle group consists of four different regions, each with a different origin. The rectus femoris originates on the anterior inferior iliac spine (AIIS). The vastus lateralis originates from the greater trochanter of the femur. The vastus medialis originates from the intertrochanteric line. The vastus intermedius originates from the shaft of the femur. Together, the muscles of the quadriceps work to extend the leg by straightening the knee.
The biceps femoris is located posterior to the femur, and is a part of the hamstring muscle group. The primary action of the biceps femoris is flexion of the leg by bending the knee.
Which muscle is responsible for the plantar flexion of the foot?
Which muscle is responsible for the plantar flexion of the foot?
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Plantar flexion involves increasing the angle between the foot and the leg (pointing the toe). The gastrocnemius is found on the posterior portion of the leg, and is contracted in order to cause plantar flexion of the foot. The other muscle to contribute to this action is the soleus, also located in the posterior portion of the leg.
The tibialis anterior is located in the anterior portion of the leg and is involved in dorsiflexion, the opposite of plantar flexion. The biceps femoris and rectus femoris are located in the thigh, and do not act on the position of the foot. The biceps femoris is involved in flexion of the knee and the rectus femoris is involved in extension of the knee.
Plantar flexion involves increasing the angle between the foot and the leg (pointing the toe). The gastrocnemius is found on the posterior portion of the leg, and is contracted in order to cause plantar flexion of the foot. The other muscle to contribute to this action is the soleus, also located in the posterior portion of the leg.
The tibialis anterior is located in the anterior portion of the leg and is involved in dorsiflexion, the opposite of plantar flexion. The biceps femoris and rectus femoris are located in the thigh, and do not act on the position of the foot. The biceps femoris is involved in flexion of the knee and the rectus femoris is involved in extension of the knee.
Which of the following innervates the gluteus maximus?
Which of the following innervates the gluteus maximus?
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The gluteus maximus is innervated by the inferior gluteal nerve. The gluteus medius and minimus are innervated by the superior gluteal nerve. The femoral nerve does not innervate the glutes, and the obturator nerve innervates muscles in the medial thigh.
The gluteus maximus is innervated by the inferior gluteal nerve. The gluteus medius and minimus are innervated by the superior gluteal nerve. The femoral nerve does not innervate the glutes, and the obturator nerve innervates muscles in the medial thigh.
Which of the following is considered a muscle of the posterior thigh, but not a part of the hamstring muscle group?
Which of the following is considered a muscle of the posterior thigh, but not a part of the hamstring muscle group?
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The short head of the biceps femoris is the only muscle of the posterior thigh that is not part of the "hamstring" muscle group. It is not cosnidered a hamstring muscle because it only crosses the knee joint; it does not act on the hip joint.
The short head of the biceps femoris is the only muscle of the posterior thigh that is not part of the "hamstring" muscle group. It is not cosnidered a hamstring muscle because it only crosses the knee joint; it does not act on the hip joint.
Which of these muscles is innervated by the common fibular divison of the sciatic nerve?
Which of these muscles is innervated by the common fibular divison of the sciatic nerve?
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Only the short head of the biceps femoris is innervatd by the common fibular division of the sciatic nerve. The long head of the biceps femoris, the semimembranous, and the semitendinous are innervated by the tibial division of the sciatic nerve. The gluteus maximus is innervated by the inferior gluteal nerve.
Only the short head of the biceps femoris is innervatd by the common fibular division of the sciatic nerve. The long head of the biceps femoris, the semimembranous, and the semitendinous are innervated by the tibial division of the sciatic nerve. The gluteus maximus is innervated by the inferior gluteal nerve.
Which of the following muscles is not innervated by the deep fibular nerve?
Which of the following muscles is not innervated by the deep fibular nerve?
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All of the incorrect answer options are muscles of the anterior compartment of the leg. Muscles of the anterior compartment are involved in dorsiflexion of the ankle and are all innervated by the deep fibular nerve.
The fibularis longus is a muscle of the lateral comaprtment of the leg. Muscles of the lateral compartment of the leg are innervated by the superficial fibular nerve.
All of the incorrect answer options are muscles of the anterior compartment of the leg. Muscles of the anterior compartment are involved in dorsiflexion of the ankle and are all innervated by the deep fibular nerve.
The fibularis longus is a muscle of the lateral comaprtment of the leg. Muscles of the lateral compartment of the leg are innervated by the superficial fibular nerve.
Located laterally to the abductor hallucis, what muscle is located in the center of the sole of the foot and is fed by the medial plantar nerve?
Located laterally to the abductor hallucis, what muscle is located in the center of the sole of the foot and is fed by the medial plantar nerve?
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The flexor digitorum brevis is sandwiched between the plantar aponeurosis and the tendons of the flexor digitorum longus. It flexes the lateral four digits at the proximal interphalangeal joints.
The flexor digitorum brevis is sandwiched between the plantar aponeurosis and the tendons of the flexor digitorum longus. It flexes the lateral four digits at the proximal interphalangeal joints.
What muscle passes through the greater sciatic notch, and is sometimes pierced by the sciatic nerve?
What muscle passes through the greater sciatic notch, and is sometimes pierced by the sciatic nerve?
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The piriformis passes through the greater sciatic notch and, in some people, is pierced by the sciatic nerve.
The piriformis passes through the greater sciatic notch and, in some people, is pierced by the sciatic nerve.
Which of the following muscles originates on the pubis and is one of three muscles that inserts into the anteromedial aspect of the tibia, or "pes anserinus?"
Which of the following muscles originates on the pubis and is one of three muscles that inserts into the anteromedial aspect of the tibia, or "pes anserinus?"
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We are looking for a muscle in the anterior/medial compartment of the thigh. Based on this we can eliminate the tensor fasia latae and vastus lateralis muscles because they are not in this compartment. The vastus lateralis muscle is part of the quadriceps, meaning it inserts into the tibial tuberosity via the quadriceps tendon, and is the lateralmost of the four quadriceps muscles. The adductor brevis does originate on the pubis, but it inserts on the femur, not the tibia, and its action is adduction of the femur. That leaves us with only the gracilis muscle as the right answer. The action of the gracilis is primarily flexion of the tibia, but it also medially rotates and adducts the hip.
We are looking for a muscle in the anterior/medial compartment of the thigh. Based on this we can eliminate the tensor fasia latae and vastus lateralis muscles because they are not in this compartment. The vastus lateralis muscle is part of the quadriceps, meaning it inserts into the tibial tuberosity via the quadriceps tendon, and is the lateralmost of the four quadriceps muscles. The adductor brevis does originate on the pubis, but it inserts on the femur, not the tibia, and its action is adduction of the femur. That leaves us with only the gracilis muscle as the right answer. The action of the gracilis is primarily flexion of the tibia, but it also medially rotates and adducts the hip.
During gait, knee buckling refers to uncontrolled flexion of the knee during stance, and can be caused by poor eccentric control of knee flexion. In weight bearing, as is the case during the stance phase of gait, knee flexion is coupled with talocrural ("ankle") dorsiflexion.
Although the quadriceps help prevent knee buckling, by eccentrically controlling knee flexion, what other muscle helps eccentrically control knee flexion during stance?
During gait, knee buckling refers to uncontrolled flexion of the knee during stance, and can be caused by poor eccentric control of knee flexion. In weight bearing, as is the case during the stance phase of gait, knee flexion is coupled with talocrural ("ankle") dorsiflexion.
Although the quadriceps help prevent knee buckling, by eccentrically controlling knee flexion, what other muscle helps eccentrically control knee flexion during stance?
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The gastrocnemis is a knee flexor, so it would promote knee buckling, not resist it. Although the tibialis anterior does not cross the knee joint, keep in mind that in weight bearing, ankle dorsiflexion is coupled with knee flexion. Accordingly, the tibialis anterior would also promote knee flexion, instead of resisting it. By the same principle, the soleus prevents knee buckling/controls knee flexion by eccentrically controlling ankle dorsiflexion.
The gastrocnemis is a knee flexor, so it would promote knee buckling, not resist it. Although the tibialis anterior does not cross the knee joint, keep in mind that in weight bearing, ankle dorsiflexion is coupled with knee flexion. Accordingly, the tibialis anterior would also promote knee flexion, instead of resisting it. By the same principle, the soleus prevents knee buckling/controls knee flexion by eccentrically controlling ankle dorsiflexion.
What muscle does not contribute to the pes anserinus?
What muscle does not contribute to the pes anserinus?
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The tendons of the sartorius, gracilis, and semitendinosus muscles combine and expand to form the pes anserinus. These muscles combine at the medial boarder of the tibial tuberosity.
Fun fact: the pes anserinus may be used in the surgical repair of the knee joint’s anterior cruciate ligament.
The rectus femoris is an anterior muscle of the thigh, and is a member of the quadriceps. It inserts at the base of the patella at the tibial tuberosity. Like all the quadriceps it helps extend the leg and is innervated by the femoral nerve.
The tendons of the sartorius, gracilis, and semitendinosus muscles combine and expand to form the pes anserinus. These muscles combine at the medial boarder of the tibial tuberosity.
Fun fact: the pes anserinus may be used in the surgical repair of the knee joint’s anterior cruciate ligament.
The rectus femoris is an anterior muscle of the thigh, and is a member of the quadriceps. It inserts at the base of the patella at the tibial tuberosity. Like all the quadriceps it helps extend the leg and is innervated by the femoral nerve.