Datasets:

MedRAG
/

textbooks

Dataset card Data Studio Files Files and versions Community

Split (1)

train · 126k rows

Subsets and Splits

id stringlengths 14 28	title stringclasses 18 values	content stringlengths 2 999	contents stringlengths 19 1.02k
Anatomy_Gray_1500	Anatomy_Gray	Muscles that provide dynamic support for the arches during walking include the tibialis anterior and posterior and the fibularis longus. The plantar aponeurosis is a thickening of deep fascia in the sole of the foot (Fig. 6.115). It is firmly anchored to the medial process of the calcaneal tuberosity and extends forward as a thick band of longitudinally arranged connective tissue fibers. The fibers diverge as they pass anteriorly and form digital bands, which enter the toes and connect with bones, ligaments, and dermis of the skin. Distal to the metatarsophalangeal joints, the digital bands of the plantar aponeurosis are interconnected by transverse fibers, which form superficial transverse metatarsal ligaments. The plantar aponeurosis supports the longitudinal arch of the foot and protects deeper structures in the sole. Fibrous sheaths of toes	Anatomy_Gray. Muscles that provide dynamic support for the arches during walking include the tibialis anterior and posterior and the fibularis longus. The plantar aponeurosis is a thickening of deep fascia in the sole of the foot (Fig. 6.115). It is firmly anchored to the medial process of the calcaneal tuberosity and extends forward as a thick band of longitudinally arranged connective tissue fibers. The fibers diverge as they pass anteriorly and form digital bands, which enter the toes and connect with bones, ligaments, and dermis of the skin. Distal to the metatarsophalangeal joints, the digital bands of the plantar aponeurosis are interconnected by transverse fibers, which form superficial transverse metatarsal ligaments. The plantar aponeurosis supports the longitudinal arch of the foot and protects deeper structures in the sole. Fibrous sheaths of toes
Anatomy_Gray_1501	Anatomy_Gray	The plantar aponeurosis supports the longitudinal arch of the foot and protects deeper structures in the sole. Fibrous sheaths of toes The tendons of the flexor digitorum longus, flexor digitorum brevis, and flexor hallucis longus muscles enter fibrous digital sheaths or tunnels on the plantar aspect of the digits (Fig. 6.116). These fibrous sheaths begin anterior to the metatarsophalangeal joints and extend to the distal phalanges. They are formed by fibrous arches and cruciate (cross-shaped) ligaments attached posteriorly to the margins of the phalanges and to the plantar ligaments associated with the metatarsophalangeal and interphalangeal joints. These fibrous tunnels hold the tendons to the bony plane and prevent tendon bowing when the toes are flexed. Within each tunnel, the tendons are surrounded by a synovial sheath.	Anatomy_Gray. The plantar aponeurosis supports the longitudinal arch of the foot and protects deeper structures in the sole. Fibrous sheaths of toes The tendons of the flexor digitorum longus, flexor digitorum brevis, and flexor hallucis longus muscles enter fibrous digital sheaths or tunnels on the plantar aspect of the digits (Fig. 6.116). These fibrous sheaths begin anterior to the metatarsophalangeal joints and extend to the distal phalanges. They are formed by fibrous arches and cruciate (cross-shaped) ligaments attached posteriorly to the margins of the phalanges and to the plantar ligaments associated with the metatarsophalangeal and interphalangeal joints. These fibrous tunnels hold the tendons to the bony plane and prevent tendon bowing when the toes are flexed. Within each tunnel, the tendons are surrounded by a synovial sheath.
Anatomy_Gray_1502	Anatomy_Gray	These fibrous tunnels hold the tendons to the bony plane and prevent tendon bowing when the toes are flexed. Within each tunnel, the tendons are surrounded by a synovial sheath. The tendons of the extensor digitorum longus, extensor digitorum brevis, and extensor hallucis longus pass into the dorsal aspect of the digits and expand over the proximal phalanges to form complex dorsal digital expansions (“extensor hoods”) (Fig. 6.117). Each extensor hood is triangular in shape with the apex attached to the distal phalanx, the central region attached to the middle (toes II to V) or proximal (toe I) phalanx, and each corner of the base wrapped around the sides of the metatarsophalangeal joint. The corners of the hoods attach mainly to the deep transverse metatarsal ligaments.	Anatomy_Gray. These fibrous tunnels hold the tendons to the bony plane and prevent tendon bowing when the toes are flexed. Within each tunnel, the tendons are surrounded by a synovial sheath. The tendons of the extensor digitorum longus, extensor digitorum brevis, and extensor hallucis longus pass into the dorsal aspect of the digits and expand over the proximal phalanges to form complex dorsal digital expansions (“extensor hoods”) (Fig. 6.117). Each extensor hood is triangular in shape with the apex attached to the distal phalanx, the central region attached to the middle (toes II to V) or proximal (toe I) phalanx, and each corner of the base wrapped around the sides of the metatarsophalangeal joint. The corners of the hoods attach mainly to the deep transverse metatarsal ligaments.
Anatomy_Gray_1503	Anatomy_Gray	Many of the intrinsic muscles of the foot insert into the free margin of the hood on each side. The attachment of these muscles into the extensor hoods allows the forces from these muscles to be distributed over the toes to cause flexion of the metatarsophalangeal joints while at the same time extending the interphalangeal joints (Fig. 6.117). The function of these movements in the foot is uncertain, but they may prevent overextension of the metatarsophalangeal joints and flexion of the interphalangeal joints when the heel is elevated off the ground and the toes grip the ground during walking.	Anatomy_Gray. Many of the intrinsic muscles of the foot insert into the free margin of the hood on each side. The attachment of these muscles into the extensor hoods allows the forces from these muscles to be distributed over the toes to cause flexion of the metatarsophalangeal joints while at the same time extending the interphalangeal joints (Fig. 6.117). The function of these movements in the foot is uncertain, but they may prevent overextension of the metatarsophalangeal joints and flexion of the interphalangeal joints when the heel is elevated off the ground and the toes grip the ground during walking.
Anatomy_Gray_1504	Anatomy_Gray	Intrinsic muscles of the foot originate and insert in the foot: the extensor digitorum brevis and extensor hallucis brevis on the dorsal aspect of the foot; all other intrinsic muscles—the dorsal and plantar interossei, flexor digiti minimi brevis, flexor hallucis brevis, flexor digitorum brevis, quadratus plantae (flexor accessorius), abductor digiti minimi, abductor hallucis, and lumbricals—are on the plantar side of the foot in the sole where they are organized into four layers. Intrinsic muscles mainly modify the actions of the long tendons and generate fine movements of the toes. All intrinsic muscles of the foot are innervated by the medial and lateral plantar branches of the tibial nerve except for the extensor digitorum brevis, which is innervated by the deep fibular nerve. The first two dorsal interossei also may receive part of their innervation from the deep fibular nerve. On the dorsal aspect	Anatomy_Gray. Intrinsic muscles of the foot originate and insert in the foot: the extensor digitorum brevis and extensor hallucis brevis on the dorsal aspect of the foot; all other intrinsic muscles—the dorsal and plantar interossei, flexor digiti minimi brevis, flexor hallucis brevis, flexor digitorum brevis, quadratus plantae (flexor accessorius), abductor digiti minimi, abductor hallucis, and lumbricals—are on the plantar side of the foot in the sole where they are organized into four layers. Intrinsic muscles mainly modify the actions of the long tendons and generate fine movements of the toes. All intrinsic muscles of the foot are innervated by the medial and lateral plantar branches of the tibial nerve except for the extensor digitorum brevis, which is innervated by the deep fibular nerve. The first two dorsal interossei also may receive part of their innervation from the deep fibular nerve. On the dorsal aspect
Anatomy_Gray_1505	Anatomy_Gray	On the dorsal aspect The extensor digitorum brevis is attached to a roughened area on the superolateral surface of the calcaneus lateral to the tarsal sinus (Fig. 6.118 and Table 6.10). The flat muscle belly passes anteromedially over the foot, deep to the tendons of the extensor digitorum longus, and forms three tendons, which enter digits II, III, and IV. The tendons join the lateral sides of the tendons of the extensor digitorum longus. The extensor digitorum brevis extends the middle three toes through attachments to the long extensor tendons and extensor hoods. It is innervated by the deep fibular nerve. The extensor hallucis brevis originates in conjunction with the extensor digitorum brevis. Its tendon attaches to the base of the proximal phalanx of the great toes. The muscle extends the metatarsophalangeal joint of the great toe and is innervated by the deep fibular nerve. In the sole	Anatomy_Gray. On the dorsal aspect The extensor digitorum brevis is attached to a roughened area on the superolateral surface of the calcaneus lateral to the tarsal sinus (Fig. 6.118 and Table 6.10). The flat muscle belly passes anteromedially over the foot, deep to the tendons of the extensor digitorum longus, and forms three tendons, which enter digits II, III, and IV. The tendons join the lateral sides of the tendons of the extensor digitorum longus. The extensor digitorum brevis extends the middle three toes through attachments to the long extensor tendons and extensor hoods. It is innervated by the deep fibular nerve. The extensor hallucis brevis originates in conjunction with the extensor digitorum brevis. Its tendon attaches to the base of the proximal phalanx of the great toes. The muscle extends the metatarsophalangeal joint of the great toe and is innervated by the deep fibular nerve. In the sole
Anatomy_Gray_1506	Anatomy_Gray	In the sole The muscles in the sole of the foot are organized into four layers. From superficial to deep, or plantar to dorsal, these layers are the first, second, third, and fourth layers. There are three components in the first layer of muscles, which is the most superficial of the four layers and is immediately deep to the plantar aponeurosis (Fig. 6.119 and Table 6.11). From medial to lateral, these muscles are the abductor hallucis, flexor digitorum brevis, and abductor digiti minimi. The abductor hallucis muscle forms the medial margin of the foot and contributes to a soft tissue bulge on the medial side of the sole (Fig. 6.119). It originates from the medial process of the calcaneal tuberosity and adjacent margins of the flexor retinaculum and plantar aponeurosis. It forms a tendon that inserts on the medial side of the base of the proximal phalanx of the great toe and on the medial sesamoid bone associated with the tendon of the flexor hallucis brevis muscle.	Anatomy_Gray. In the sole The muscles in the sole of the foot are organized into four layers. From superficial to deep, or plantar to dorsal, these layers are the first, second, third, and fourth layers. There are three components in the first layer of muscles, which is the most superficial of the four layers and is immediately deep to the plantar aponeurosis (Fig. 6.119 and Table 6.11). From medial to lateral, these muscles are the abductor hallucis, flexor digitorum brevis, and abductor digiti minimi. The abductor hallucis muscle forms the medial margin of the foot and contributes to a soft tissue bulge on the medial side of the sole (Fig. 6.119). It originates from the medial process of the calcaneal tuberosity and adjacent margins of the flexor retinaculum and plantar aponeurosis. It forms a tendon that inserts on the medial side of the base of the proximal phalanx of the great toe and on the medial sesamoid bone associated with the tendon of the flexor hallucis brevis muscle.
Anatomy_Gray_1507	Anatomy_Gray	The abductor hallucis abducts and flexes the great toe at the metatarsophalangeal joint and is innervated by the medial plantar branch of the tibial nerve. The flexor digitorum brevis muscle lies immediately superior to the plantar aponeurosis and inferior to the tendons of the flexor digitorum longus in the sole of the foot (Fig. 6.119). The flat spindle-shaped muscle belly originates as a tendon from the medial process of the calcaneal tuberosity and from the adjacent plantar aponeurosis. The muscle fibers of the flexor digitorum brevis converge anteriorly to form four tendons, which each enter one of the lateral four toes. Near the base of the proximal phalanx of the toe, each tendon splits to pass dorsally around each side of the tendon of the flexor digitorum longus and attach to the margins of the middle phalanx. The flexor digitorum brevis flexes the lateral four toes at the proximal interphalangeal joints and is innervated by the medial plantar branch of the tibial nerve.	Anatomy_Gray. The abductor hallucis abducts and flexes the great toe at the metatarsophalangeal joint and is innervated by the medial plantar branch of the tibial nerve. The flexor digitorum brevis muscle lies immediately superior to the plantar aponeurosis and inferior to the tendons of the flexor digitorum longus in the sole of the foot (Fig. 6.119). The flat spindle-shaped muscle belly originates as a tendon from the medial process of the calcaneal tuberosity and from the adjacent plantar aponeurosis. The muscle fibers of the flexor digitorum brevis converge anteriorly to form four tendons, which each enter one of the lateral four toes. Near the base of the proximal phalanx of the toe, each tendon splits to pass dorsally around each side of the tendon of the flexor digitorum longus and attach to the margins of the middle phalanx. The flexor digitorum brevis flexes the lateral four toes at the proximal interphalangeal joints and is innervated by the medial plantar branch of the tibial nerve.
Anatomy_Gray_1508	Anatomy_Gray	The flexor digitorum brevis flexes the lateral four toes at the proximal interphalangeal joints and is innervated by the medial plantar branch of the tibial nerve. The abductor digiti minimi muscle is on the lateral side of the foot and contributes to the large lateral plantar eminence on the sole (Fig. 6.119). It has a broad base of origin, mainly from the lateral and medial processes of the calcaneal tuberosity and from a fibrous band of connective tissue, which connects the calcaneus with the base of metatarsal V. The abductor digiti minimi forms a tendon, which travels in a shallow groove on the plantar surface of the base of metatarsal V and continues forward to attach to the lateral side of the base of the proximal phalanx of the little toe. The abductor digiti minimi abducts the little toe at the metatarsophalangeal joint and is innervated by the lateral plantar branch of the tibial nerve.	Anatomy_Gray. The flexor digitorum brevis flexes the lateral four toes at the proximal interphalangeal joints and is innervated by the medial plantar branch of the tibial nerve. The abductor digiti minimi muscle is on the lateral side of the foot and contributes to the large lateral plantar eminence on the sole (Fig. 6.119). It has a broad base of origin, mainly from the lateral and medial processes of the calcaneal tuberosity and from a fibrous band of connective tissue, which connects the calcaneus with the base of metatarsal V. The abductor digiti minimi forms a tendon, which travels in a shallow groove on the plantar surface of the base of metatarsal V and continues forward to attach to the lateral side of the base of the proximal phalanx of the little toe. The abductor digiti minimi abducts the little toe at the metatarsophalangeal joint and is innervated by the lateral plantar branch of the tibial nerve.
Anatomy_Gray_1509	Anatomy_Gray	The abductor digiti minimi abducts the little toe at the metatarsophalangeal joint and is innervated by the lateral plantar branch of the tibial nerve. The second muscle layer in the sole of the foot is associated with the tendons of the flexor digitorum longus muscle, which pass through this layer, and consists of the quadratus plantae and four lumbrical muscles (Fig. 6.120 and Table 6.12). The quadratus plantae muscle is a flat quadrangular muscle with two heads of origin (Fig. 6.120): One of the heads originates from the medial surface of the calcaneus inferior to the sustentaculum tali. The other head originates from the inferior surface of the calcaneus anterior to the lateral process of the calcaneal tuberosity and the attachment of the long plantar ligament. The quadratus plantae muscle inserts into the lateral side of the tendon of the flexor digitorum longus in the proximal half of the sole of the foot near where the tendon divides.	Anatomy_Gray. The abductor digiti minimi abducts the little toe at the metatarsophalangeal joint and is innervated by the lateral plantar branch of the tibial nerve. The second muscle layer in the sole of the foot is associated with the tendons of the flexor digitorum longus muscle, which pass through this layer, and consists of the quadratus plantae and four lumbrical muscles (Fig. 6.120 and Table 6.12). The quadratus plantae muscle is a flat quadrangular muscle with two heads of origin (Fig. 6.120): One of the heads originates from the medial surface of the calcaneus inferior to the sustentaculum tali. The other head originates from the inferior surface of the calcaneus anterior to the lateral process of the calcaneal tuberosity and the attachment of the long plantar ligament. The quadratus plantae muscle inserts into the lateral side of the tendon of the flexor digitorum longus in the proximal half of the sole of the foot near where the tendon divides.
Anatomy_Gray_1510	Anatomy_Gray	The quadratus plantae muscle inserts into the lateral side of the tendon of the flexor digitorum longus in the proximal half of the sole of the foot near where the tendon divides. The quadratus plantae assists the flexor digitorum longus tendon in flexing the toes and may also adjust the “line of pull” of this tendon as it enters the sole of the foot from the medial side. The muscle is innervated by the lateral plantar nerve. The lumbrical muscles are four worm-like muscles that originate from the tendons of the flexor digitorum longus and pass dorsally to insert into the free medial margins of the extensor hoods of the four lateral toes (Fig. 6.120). The first lumbrical originates from the medial side of the tendon of the flexor digitorum longus that is associated with the second toe. The remaining three muscles are bipennate and originate from the sides of adjacent tendons.	Anatomy_Gray. The quadratus plantae muscle inserts into the lateral side of the tendon of the flexor digitorum longus in the proximal half of the sole of the foot near where the tendon divides. The quadratus plantae assists the flexor digitorum longus tendon in flexing the toes and may also adjust the “line of pull” of this tendon as it enters the sole of the foot from the medial side. The muscle is innervated by the lateral plantar nerve. The lumbrical muscles are four worm-like muscles that originate from the tendons of the flexor digitorum longus and pass dorsally to insert into the free medial margins of the extensor hoods of the four lateral toes (Fig. 6.120). The first lumbrical originates from the medial side of the tendon of the flexor digitorum longus that is associated with the second toe. The remaining three muscles are bipennate and originate from the sides of adjacent tendons.
Anatomy_Gray_1511	Anatomy_Gray	The lumbrical muscles act through the extensor hoods to resist excessive extension of the metatarsophalangeal joints and flexion of the interphalangeal joints when the heel leaves the ground during walking. The first lumbrical is innervated by the medial plantar nerve, while the other three are innervated by the lateral plantar nerve. There are three muscles in the third layer in the sole of the foot (Fig. 6.122 and Table 6.13): Two (the flexor hallucis brevis and adductor hallucis) are associated with the great toe. The third (the flexor digiti minimi brevis) is associated with the little toe. The flexor hallucis brevis muscle has two tendinous heads of origin (Fig. 6.122): The lateral head originates from the plantar surfaces of the cuboid, behind the groove for the fibularis longus, and adjacent surface of the lateral cuneiform. The medial head originates from the tendon of the tibialis posterior muscle as it passes into the sole of the foot.	Anatomy_Gray. The lumbrical muscles act through the extensor hoods to resist excessive extension of the metatarsophalangeal joints and flexion of the interphalangeal joints when the heel leaves the ground during walking. The first lumbrical is innervated by the medial plantar nerve, while the other three are innervated by the lateral plantar nerve. There are three muscles in the third layer in the sole of the foot (Fig. 6.122 and Table 6.13): Two (the flexor hallucis brevis and adductor hallucis) are associated with the great toe. The third (the flexor digiti minimi brevis) is associated with the little toe. The flexor hallucis brevis muscle has two tendinous heads of origin (Fig. 6.122): The lateral head originates from the plantar surfaces of the cuboid, behind the groove for the fibularis longus, and adjacent surface of the lateral cuneiform. The medial head originates from the tendon of the tibialis posterior muscle as it passes into the sole of the foot.
Anatomy_Gray_1512	Anatomy_Gray	The medial head originates from the tendon of the tibialis posterior muscle as it passes into the sole of the foot. The medial and lateral heads unite and give rise to a muscle belly, which itself is separated into medial and lateral parts adjacent to the plantar surface of metatarsal I. Each part of the muscle gives rise to a tendon that inserts on either the lateral or medial side of the base of the proximal phalanx of the great toe. A sesamoid bone occurs in each tendon of the flexor hallucis brevis as it crosses the plantar surface of the head of metatarsal I. The tendon of the flexor hallucis longus passes between the sesamoid bones. The flexor hallucis brevis flexes the metatarsophalangeal joint of the great toe and is innervated by the medial plantar nerve. The adductor hallucis muscle originates by two muscular heads, transverse and oblique, which join near their ends to insert into the lateral side of the base of the proximal phalanx of the great toe (Fig. 6.122):	Anatomy_Gray. The medial head originates from the tendon of the tibialis posterior muscle as it passes into the sole of the foot. The medial and lateral heads unite and give rise to a muscle belly, which itself is separated into medial and lateral parts adjacent to the plantar surface of metatarsal I. Each part of the muscle gives rise to a tendon that inserts on either the lateral or medial side of the base of the proximal phalanx of the great toe. A sesamoid bone occurs in each tendon of the flexor hallucis brevis as it crosses the plantar surface of the head of metatarsal I. The tendon of the flexor hallucis longus passes between the sesamoid bones. The flexor hallucis brevis flexes the metatarsophalangeal joint of the great toe and is innervated by the medial plantar nerve. The adductor hallucis muscle originates by two muscular heads, transverse and oblique, which join near their ends to insert into the lateral side of the base of the proximal phalanx of the great toe (Fig. 6.122):
Anatomy_Gray_1513	Anatomy_Gray	The transverse head originates from the plantar ligaments associated with the metatarsophalangeal joints of the lateral three toes and from the associated deep transverse metatarsal ligaments—the muscle crosses the sole of the foot transversely from lateral to medial and joins the oblique head near the base of the great toe. The oblique head is larger than the transverse head and originates from the plantar surfaces of the bases of metatarsals II to IV and from the sheath covering the fibularis longus muscle—this head passes anterolaterally through the sole of the foot and joins the transverse head. The tendon of insertion of the adductor hallucis attaches to the lateral sesamoid bone associated with the tendon of the flexor hallucis brevis muscle in addition to attaching to the proximal phalanx. The adductor hallucis adducts the great toe at the metatarsophalangeal joint and is innervated by the lateral plantar nerve.	Anatomy_Gray. The transverse head originates from the plantar ligaments associated with the metatarsophalangeal joints of the lateral three toes and from the associated deep transverse metatarsal ligaments—the muscle crosses the sole of the foot transversely from lateral to medial and joins the oblique head near the base of the great toe. The oblique head is larger than the transverse head and originates from the plantar surfaces of the bases of metatarsals II to IV and from the sheath covering the fibularis longus muscle—this head passes anterolaterally through the sole of the foot and joins the transverse head. The tendon of insertion of the adductor hallucis attaches to the lateral sesamoid bone associated with the tendon of the flexor hallucis brevis muscle in addition to attaching to the proximal phalanx. The adductor hallucis adducts the great toe at the metatarsophalangeal joint and is innervated by the lateral plantar nerve.
Anatomy_Gray_1514	Anatomy_Gray	The adductor hallucis adducts the great toe at the metatarsophalangeal joint and is innervated by the lateral plantar nerve. The flexor digiti minimi brevis muscle originates from the plantar surface of the base of metatarsal V and adjacent sheath of the fibularis longus tendon (Fig. 6.122). It inserts on the lateral side of the base of the proximal phalanx of the little toe. The flexor digiti minimi brevis flexes the little toe at the metatarsophalangeal joint and is innervated by the lateral plantar nerve. There are two muscle groups in the deepest muscle layer in the sole of the foot, the dorsal and plantar interossei (Fig. 6.123 and Table 6.14). The four dorsal interossei are the most superior muscles in the sole of the foot and abduct the second to fourth toes relative to the long axis through the second toe (Fig. 6.123). All four muscles are bipennate and originate from the sides of adjacent metatarsals.	Anatomy_Gray. The adductor hallucis adducts the great toe at the metatarsophalangeal joint and is innervated by the lateral plantar nerve. The flexor digiti minimi brevis muscle originates from the plantar surface of the base of metatarsal V and adjacent sheath of the fibularis longus tendon (Fig. 6.122). It inserts on the lateral side of the base of the proximal phalanx of the little toe. The flexor digiti minimi brevis flexes the little toe at the metatarsophalangeal joint and is innervated by the lateral plantar nerve. There are two muscle groups in the deepest muscle layer in the sole of the foot, the dorsal and plantar interossei (Fig. 6.123 and Table 6.14). The four dorsal interossei are the most superior muscles in the sole of the foot and abduct the second to fourth toes relative to the long axis through the second toe (Fig. 6.123). All four muscles are bipennate and originate from the sides of adjacent metatarsals.
Anatomy_Gray_1515	Anatomy_Gray	The tendons of the dorsal interossei insert into the free margin of the extensor hoods and base of the proximal phalanges of the toes. The second toe can be abducted to either side of its long axis, so it has two dorsal interossei associated with it, one on each side. The third and fourth toes have a dorsal interosseous muscle on their lateral sides only. The great and little toes have their own abductors (the abductor hallucis and abductor digiti minimi) in the first layer of muscles in the sole of the foot. In addition to abduction, the dorsal interossei act through the extensor hoods to resist extension of the metatarsophalangeal joints and flexion of the interphalangeal joints. The dorsal interossei are innervated by the lateral plantar nerve. The first and second dorsal interossei also receive branches on their superior surfaces from the deep fibular nerve.	Anatomy_Gray. The tendons of the dorsal interossei insert into the free margin of the extensor hoods and base of the proximal phalanges of the toes. The second toe can be abducted to either side of its long axis, so it has two dorsal interossei associated with it, one on each side. The third and fourth toes have a dorsal interosseous muscle on their lateral sides only. The great and little toes have their own abductors (the abductor hallucis and abductor digiti minimi) in the first layer of muscles in the sole of the foot. In addition to abduction, the dorsal interossei act through the extensor hoods to resist extension of the metatarsophalangeal joints and flexion of the interphalangeal joints. The dorsal interossei are innervated by the lateral plantar nerve. The first and second dorsal interossei also receive branches on their superior surfaces from the deep fibular nerve.
Anatomy_Gray_1516	Anatomy_Gray	The dorsal interossei are innervated by the lateral plantar nerve. The first and second dorsal interossei also receive branches on their superior surfaces from the deep fibular nerve. The three plantar interossei adduct the third, fourth, and little toes toward the long axis through the second toe (Fig. 6.123). Each plantar interosseous muscle originates from the medial side of its associated metatarsal and inserts into the medial free margin of the extensor hood and base of the proximal phalanx. The great toe has its own adductor (the adductor hallucis) in the third layer of muscles in the sole of the foot and the second toe is adducted back to its longitudinal axis by using one of its dorsal interossei. In addition to adduction, the plantar interossei act through the extensor hoods to resist extension of the metatarsophalangeal joints and flexion of the interphalangeal joints. All are innervated by the lateral plantar nerve.	Anatomy_Gray. The dorsal interossei are innervated by the lateral plantar nerve. The first and second dorsal interossei also receive branches on their superior surfaces from the deep fibular nerve. The three plantar interossei adduct the third, fourth, and little toes toward the long axis through the second toe (Fig. 6.123). Each plantar interosseous muscle originates from the medial side of its associated metatarsal and inserts into the medial free margin of the extensor hood and base of the proximal phalanx. The great toe has its own adductor (the adductor hallucis) in the third layer of muscles in the sole of the foot and the second toe is adducted back to its longitudinal axis by using one of its dorsal interossei. In addition to adduction, the plantar interossei act through the extensor hoods to resist extension of the metatarsophalangeal joints and flexion of the interphalangeal joints. All are innervated by the lateral plantar nerve.
Anatomy_Gray_1517	Anatomy_Gray	Blood supply to the foot is by branches of the posterior tibial and dorsalis pedis (dorsal artery of the foot) arteries. The posterior tibial artery enters the sole and bifurcates into lateral and medial plantar arteries. The lateral plantar artery joins with the terminal end of the dorsalis pedis artery (the deep plantar artery) to form the deep plantar arch. Branches from this arch supply the toes. The dorsalis pedis artery is the continuation of the anterior tibial artery, passes onto the dorsal aspect of the foot and then inferiorly, as the deep plantar artery, between metatarsals I and II to enter the sole of the foot.	Anatomy_Gray. Blood supply to the foot is by branches of the posterior tibial and dorsalis pedis (dorsal artery of the foot) arteries. The posterior tibial artery enters the sole and bifurcates into lateral and medial plantar arteries. The lateral plantar artery joins with the terminal end of the dorsalis pedis artery (the deep plantar artery) to form the deep plantar arch. Branches from this arch supply the toes. The dorsalis pedis artery is the continuation of the anterior tibial artery, passes onto the dorsal aspect of the foot and then inferiorly, as the deep plantar artery, between metatarsals I and II to enter the sole of the foot.
Anatomy_Gray_1518	Anatomy_Gray	The posterior tibial artery enters the foot through the tarsal tunnel on the medial side of the ankle and posterior to the medial malleolus. Midway between the medial malleolus and the heel, the pulse of the posterior tibial artery is palpable because here the artery is covered only by a thin layer of retinaculum, by superficial connective tissue, and by skin. Near this location, the posterior tibial artery bifurcates into a small medial plantar artery and a much larger lateral plantar artery.	Anatomy_Gray. The posterior tibial artery enters the foot through the tarsal tunnel on the medial side of the ankle and posterior to the medial malleolus. Midway between the medial malleolus and the heel, the pulse of the posterior tibial artery is palpable because here the artery is covered only by a thin layer of retinaculum, by superficial connective tissue, and by skin. Near this location, the posterior tibial artery bifurcates into a small medial plantar artery and a much larger lateral plantar artery.
Anatomy_Gray_1519	Anatomy_Gray	The lateral plantar artery passes anterolaterally into the sole of the foot, first deep to the proximal end of the abductor hallucis muscle and then between the quadratus plantae and flexor digitorum brevis muscles (Fig. 6.124). It reaches the base of metatarsal V where it lies in the groove between the flexor digitorum brevis and abductor digiti minimi muscles. From here, the lateral plantar artery curves medially to form the deep plantar arch, which crosses the deep plane of the sole on the metatarsal bases and the interossei muscles. Between the bases of metatarsals I and II, the deep plantar arch joins with the terminal branch (deep plantar artery) of the dorsalis pedis artery, which enters the sole from the dorsal side of the foot.	Anatomy_Gray. The lateral plantar artery passes anterolaterally into the sole of the foot, first deep to the proximal end of the abductor hallucis muscle and then between the quadratus plantae and flexor digitorum brevis muscles (Fig. 6.124). It reaches the base of metatarsal V where it lies in the groove between the flexor digitorum brevis and abductor digiti minimi muscles. From here, the lateral plantar artery curves medially to form the deep plantar arch, which crosses the deep plane of the sole on the metatarsal bases and the interossei muscles. Between the bases of metatarsals I and II, the deep plantar arch joins with the terminal branch (deep plantar artery) of the dorsalis pedis artery, which enters the sole from the dorsal side of the foot.
Anatomy_Gray_1520	Anatomy_Gray	Major branches of the deep plantar arch include: a digital branch to the lateral side of the little toe; four plantar metatarsal arteries, which supply digital branches to adjacent sides of toes I to V and the medial side of the great toe; and three perforating arteries, which pass between the bases of metatarsals II to V to anastomose with vessels on the dorsal aspect of the foot. The medial plantar artery passes into the sole of the foot by passing deep to the proximal end of the abductor hallucis muscle (Fig. 6.124). It supplies a deep branch to adjacent muscles and then passes forward in the groove between the abductor hallucis and the flexor digitorum brevis muscles. It ends by joining the digital branch of the deep plantar arch, which supplies the medial side of the great toe.	Anatomy_Gray. Major branches of the deep plantar arch include: a digital branch to the lateral side of the little toe; four plantar metatarsal arteries, which supply digital branches to adjacent sides of toes I to V and the medial side of the great toe; and three perforating arteries, which pass between the bases of metatarsals II to V to anastomose with vessels on the dorsal aspect of the foot. The medial plantar artery passes into the sole of the foot by passing deep to the proximal end of the abductor hallucis muscle (Fig. 6.124). It supplies a deep branch to adjacent muscles and then passes forward in the groove between the abductor hallucis and the flexor digitorum brevis muscles. It ends by joining the digital branch of the deep plantar arch, which supplies the medial side of the great toe.
Anatomy_Gray_1521	Anatomy_Gray	Near the base of metatarsal I, the medial plantar artery gives rise to a superficial branch, which divides into three vessels that pass superficial to the flexor digitorum brevis muscle to join the plantar metatarsal arteries from the deep plantar arch. The dorsalis pedis artery is the continuation of the anterior tibial artery and begins as the anterior tibial artery crosses the ankle joint (Fig. 6.125). It passes anteriorly over the dorsal aspect of the talus, navicular, and intermediate cuneiform bones, and then passes inferiorly, as the deep plantar artery, between the two heads of the first dorsal interosseous muscle to join the deep plantar arch in the sole of the foot. The pulse of the dorsalis pedis artery on the dorsal surface of the foot can be felt by gently palpating the vessel against the underlying tarsal bones between the tendons of the extensor hallucis longus and the extensor digitorum longus to the second toe.	Anatomy_Gray. Near the base of metatarsal I, the medial plantar artery gives rise to a superficial branch, which divides into three vessels that pass superficial to the flexor digitorum brevis muscle to join the plantar metatarsal arteries from the deep plantar arch. The dorsalis pedis artery is the continuation of the anterior tibial artery and begins as the anterior tibial artery crosses the ankle joint (Fig. 6.125). It passes anteriorly over the dorsal aspect of the talus, navicular, and intermediate cuneiform bones, and then passes inferiorly, as the deep plantar artery, between the two heads of the first dorsal interosseous muscle to join the deep plantar arch in the sole of the foot. The pulse of the dorsalis pedis artery on the dorsal surface of the foot can be felt by gently palpating the vessel against the underlying tarsal bones between the tendons of the extensor hallucis longus and the extensor digitorum longus to the second toe.
Anatomy_Gray_1522	Anatomy_Gray	Branches of the dorsalis pedis artery include lateral and medial tarsal branches, an arcuate artery, and a first dorsal metatarsal artery: The tarsal arteries pass medially and laterally over the tarsal bones, supplying adjacent structures and anastomosing with a network of vessels formed around the ankle. The arcuate artery passes laterally over the dorsal aspect of the metatarsals near their bases and gives rise to three dorsal metatarsal arteries, which supply dorsal digital arteries to adjacent sides of digits II to V, and to a dorsal digital artery that supplies the lateral side of digit V. The first dorsal metatarsal artery (the last branch of the dorsalis pedis artery before the dorsalis pedis artery continues as the deep plantar artery into the sole of the foot) supplies dorsal digital branches to adjacent sides of the great and second toes.	Anatomy_Gray. Branches of the dorsalis pedis artery include lateral and medial tarsal branches, an arcuate artery, and a first dorsal metatarsal artery: The tarsal arteries pass medially and laterally over the tarsal bones, supplying adjacent structures and anastomosing with a network of vessels formed around the ankle. The arcuate artery passes laterally over the dorsal aspect of the metatarsals near their bases and gives rise to three dorsal metatarsal arteries, which supply dorsal digital arteries to adjacent sides of digits II to V, and to a dorsal digital artery that supplies the lateral side of digit V. The first dorsal metatarsal artery (the last branch of the dorsalis pedis artery before the dorsalis pedis artery continues as the deep plantar artery into the sole of the foot) supplies dorsal digital branches to adjacent sides of the great and second toes.
Anatomy_Gray_1523	Anatomy_Gray	The dorsal metatarsal arteries connect with perforating branches from the deep plantar arch and similar branches from the plantar metatarsal arteries. There are interconnected networks of deep and superficial veins in the foot. The deep veins follow the arteries. Superficial veins drain into a dorsal venous arch on the dorsal surface of the foot over the metatarsals (Fig. 6.126): The great saphenous vein originates from the medial side of the arch and passes anterior to the medial malleolus and onto the medial side of the leg. The small saphenous vein originates from the lateral side of the arch and passes posterior to the lateral malleolus and onto the back of the leg. The foot is supplied by the tibial, deep fibular, superficial fibular, sural, and saphenous nerves: All five nerves contribute to cutaneous or general sensory innervation.	Anatomy_Gray. The dorsal metatarsal arteries connect with perforating branches from the deep plantar arch and similar branches from the plantar metatarsal arteries. There are interconnected networks of deep and superficial veins in the foot. The deep veins follow the arteries. Superficial veins drain into a dorsal venous arch on the dorsal surface of the foot over the metatarsals (Fig. 6.126): The great saphenous vein originates from the medial side of the arch and passes anterior to the medial malleolus and onto the medial side of the leg. The small saphenous vein originates from the lateral side of the arch and passes posterior to the lateral malleolus and onto the back of the leg. The foot is supplied by the tibial, deep fibular, superficial fibular, sural, and saphenous nerves: All five nerves contribute to cutaneous or general sensory innervation.
Anatomy_Gray_1524	Anatomy_Gray	The foot is supplied by the tibial, deep fibular, superficial fibular, sural, and saphenous nerves: All five nerves contribute to cutaneous or general sensory innervation. The tibial nerve innervates all intrinsic muscles of the foot except for the extensor digitorum brevis, which is innervated by the deep fibular nerve. The deep fibular nerve often also contributes to the innervation of the first and second dorsal interossei. The tibial nerve enters the foot through the tarsal tunnel posterior to the medial malleolus. In the tunnel, the nerve is lateral to the posterior tibial artery, and gives origin to medial calcaneal branches, which penetrate the flexor retinaculum to supply the heel. Midway between the medial malleolus and the heel, the tibial nerve bifurcates with the posterior tibial artery into: a large medial plantar nerve, and a smaller lateral plantar nerve (Fig. 6.127). The medial and lateral plantar nerves lie together between their corresponding arteries.	Anatomy_Gray. The foot is supplied by the tibial, deep fibular, superficial fibular, sural, and saphenous nerves: All five nerves contribute to cutaneous or general sensory innervation. The tibial nerve innervates all intrinsic muscles of the foot except for the extensor digitorum brevis, which is innervated by the deep fibular nerve. The deep fibular nerve often also contributes to the innervation of the first and second dorsal interossei. The tibial nerve enters the foot through the tarsal tunnel posterior to the medial malleolus. In the tunnel, the nerve is lateral to the posterior tibial artery, and gives origin to medial calcaneal branches, which penetrate the flexor retinaculum to supply the heel. Midway between the medial malleolus and the heel, the tibial nerve bifurcates with the posterior tibial artery into: a large medial plantar nerve, and a smaller lateral plantar nerve (Fig. 6.127). The medial and lateral plantar nerves lie together between their corresponding arteries.
Anatomy_Gray_1525	Anatomy_Gray	The medial and lateral plantar nerves lie together between their corresponding arteries. The medial plantar nerve is the major sensory nerve in the sole of the foot (Fig. 6.127). It innervates skin on most of the anterior two-thirds of the sole and adjacent surfaces of the medial three and one-half toes, which includes the great toe. In addition to this large area of plantar skin, the nerve also innervates four intrinsic muscles—the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and first lumbrical. The medial plantar nerve passes into the sole of the foot deep to the abductor hallucis muscle and forward in the groove between the abductor hallucis and flexor digitorum brevis, supplying branches to both these muscles.	Anatomy_Gray. The medial and lateral plantar nerves lie together between their corresponding arteries. The medial plantar nerve is the major sensory nerve in the sole of the foot (Fig. 6.127). It innervates skin on most of the anterior two-thirds of the sole and adjacent surfaces of the medial three and one-half toes, which includes the great toe. In addition to this large area of plantar skin, the nerve also innervates four intrinsic muscles—the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and first lumbrical. The medial plantar nerve passes into the sole of the foot deep to the abductor hallucis muscle and forward in the groove between the abductor hallucis and flexor digitorum brevis, supplying branches to both these muscles.
Anatomy_Gray_1526	Anatomy_Gray	The medial plantar nerve supplies a digital branch (proper plantar digital nerve) to the medial side of the great toe and then divides into three nerves (common plantar digital nerves) on the plantar surface of the flexor digitorum brevis, which continue forward to supply proper plantar digital branches to adjacent surfaces of toes I to IV. The nerve to the first lumbrical originates from the first common plantar digital nerve. The lateral plantar nerve is an important motor nerve in the foot because it innervates all intrinsic muscles in the sole, except for the muscles supplied by the medial plantar nerve (the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and first lumbrical) (Fig. 6.127). It also innervates a strip of skin on the lateral side of the anterior two-thirds of the sole and the adjacent plantar surfaces of the lateral one and one-half digits.	Anatomy_Gray. The medial plantar nerve supplies a digital branch (proper plantar digital nerve) to the medial side of the great toe and then divides into three nerves (common plantar digital nerves) on the plantar surface of the flexor digitorum brevis, which continue forward to supply proper plantar digital branches to adjacent surfaces of toes I to IV. The nerve to the first lumbrical originates from the first common plantar digital nerve. The lateral plantar nerve is an important motor nerve in the foot because it innervates all intrinsic muscles in the sole, except for the muscles supplied by the medial plantar nerve (the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and first lumbrical) (Fig. 6.127). It also innervates a strip of skin on the lateral side of the anterior two-thirds of the sole and the adjacent plantar surfaces of the lateral one and one-half digits.
Anatomy_Gray_1527	Anatomy_Gray	The lateral plantar nerve enters the sole of the foot by passing deep to the proximal attachment of the abductor hallucis muscle. It continues laterally and anteriorly across the sole between the flexor digitorum brevis and quadratus plantae muscles, supplying branches to both these muscles, and then divides near the head of metatarsal V into deep and superficial branches. The superficial branch of the lateral plantar nerve gives rise to a proper plantar digital nerve, which supplies skin on the lateral side of the little toe, and to a common plantar digital nerve, which divides to supply proper plantar digital nerves to skin on the adjacent sides of toes IV and V. The proper plantar digital nerve to the lateral side of the little toe also innervates the flexor digiti minimi brevis and the dorsal and plantar interossei muscles between metatarsals IV and V.	Anatomy_Gray. The lateral plantar nerve enters the sole of the foot by passing deep to the proximal attachment of the abductor hallucis muscle. It continues laterally and anteriorly across the sole between the flexor digitorum brevis and quadratus plantae muscles, supplying branches to both these muscles, and then divides near the head of metatarsal V into deep and superficial branches. The superficial branch of the lateral plantar nerve gives rise to a proper plantar digital nerve, which supplies skin on the lateral side of the little toe, and to a common plantar digital nerve, which divides to supply proper plantar digital nerves to skin on the adjacent sides of toes IV and V. The proper plantar digital nerve to the lateral side of the little toe also innervates the flexor digiti minimi brevis and the dorsal and plantar interossei muscles between metatarsals IV and V.
Anatomy_Gray_1528	Anatomy_Gray	The proper plantar digital nerve to the lateral side of the little toe also innervates the flexor digiti minimi brevis and the dorsal and plantar interossei muscles between metatarsals IV and V. The deep branch of the lateral plantar nerve is motor and accompanies the lateral plantar artery deep to the long flexor tendons and the adductor hallucis muscle. It supplies branches to the second to fourth lumbrical muscles, the adductor hallucis muscle, and all interossei except those between metatarsals IV and V, which are innervated by the superficial branch. The deep fibular nerve innervates the extensor digitorum brevis, contributes to the innervation of the first two dorsal interossei muscles, and supplies general sensory branches to the skin on the adjacent dorsal sides of the first and second toes and to the web space between them (Fig. 6.128).	Anatomy_Gray. The proper plantar digital nerve to the lateral side of the little toe also innervates the flexor digiti minimi brevis and the dorsal and plantar interossei muscles between metatarsals IV and V. The deep branch of the lateral plantar nerve is motor and accompanies the lateral plantar artery deep to the long flexor tendons and the adductor hallucis muscle. It supplies branches to the second to fourth lumbrical muscles, the adductor hallucis muscle, and all interossei except those between metatarsals IV and V, which are innervated by the superficial branch. The deep fibular nerve innervates the extensor digitorum brevis, contributes to the innervation of the first two dorsal interossei muscles, and supplies general sensory branches to the skin on the adjacent dorsal sides of the first and second toes and to the web space between them (Fig. 6.128).
Anatomy_Gray_1529	Anatomy_Gray	The deep fibular nerve enters the dorsal aspect of the foot on the lateral side of the dorsalis pedis artery, and is parallel with and lateral to the tendon of the extensor hallucis longus muscle. Just distal to the ankle joint, the nerve gives origin to a lateral branch, which innervates the extensor digitorum brevis from its deep surface. The deep fibular nerve continues forward on the dorsal surface of the foot, penetrates deep fascia between metatarsals I and II near the metatarsophalangeal joints, and then divides into two dorsal digital nerves, which supply skin over adjacent surfaces of toes I and II down to the beginning of the nail beds. Small motor branches, which contribute to the supply of the first two dorsal interossei muscles, originate from the deep fibular nerve before it penetrates deep fascia.	Anatomy_Gray. The deep fibular nerve enters the dorsal aspect of the foot on the lateral side of the dorsalis pedis artery, and is parallel with and lateral to the tendon of the extensor hallucis longus muscle. Just distal to the ankle joint, the nerve gives origin to a lateral branch, which innervates the extensor digitorum brevis from its deep surface. The deep fibular nerve continues forward on the dorsal surface of the foot, penetrates deep fascia between metatarsals I and II near the metatarsophalangeal joints, and then divides into two dorsal digital nerves, which supply skin over adjacent surfaces of toes I and II down to the beginning of the nail beds. Small motor branches, which contribute to the supply of the first two dorsal interossei muscles, originate from the deep fibular nerve before it penetrates deep fascia.
Anatomy_Gray_1530	Anatomy_Gray	Small motor branches, which contribute to the supply of the first two dorsal interossei muscles, originate from the deep fibular nerve before it penetrates deep fascia. The superficial fibular nerve is sensory to most skin on the dorsal aspect of the foot and toes except for skin on adjacent sides of toes I and II (which is innervated by the deep fibular nerve) and skin on the lateral side of the foot and little toe (which is innervated by the sural nerve; Fig. 6.128). The superficial fibular nerve penetrates deep fascia on the anterolateral side of the lower leg and enters the dorsal aspect of the foot in superficial fascia. It gives rise to cutaneous branches and dorsal digital nerves along its course.	Anatomy_Gray. Small motor branches, which contribute to the supply of the first two dorsal interossei muscles, originate from the deep fibular nerve before it penetrates deep fascia. The superficial fibular nerve is sensory to most skin on the dorsal aspect of the foot and toes except for skin on adjacent sides of toes I and II (which is innervated by the deep fibular nerve) and skin on the lateral side of the foot and little toe (which is innervated by the sural nerve; Fig. 6.128). The superficial fibular nerve penetrates deep fascia on the anterolateral side of the lower leg and enters the dorsal aspect of the foot in superficial fascia. It gives rise to cutaneous branches and dorsal digital nerves along its course.
Anatomy_Gray_1531	Anatomy_Gray	The sural nerve is a cutaneous branch of the tibial nerve that originates high in the leg. It enters the foot in superficial fascia posterior to the lateral malleolus close to the short saphenous vein. Terminal branches innervate skin on the lateral side of the foot and dorsolateral surface of the little toe (Fig. 6.128B). The saphenous nerve is a cutaneous branch of the femoral nerve that originates in the thigh. Terminal branches enter the foot in superficial fascia on the medial side of the ankle and supply skin on the medial side of the proximal foot (Fig. 6.128B). Tendons, muscles, and bony landmarks in the lower limb are used to locate major arteries, veins, and nerves.	Anatomy_Gray. The sural nerve is a cutaneous branch of the tibial nerve that originates high in the leg. It enters the foot in superficial fascia posterior to the lateral malleolus close to the short saphenous vein. Terminal branches innervate skin on the lateral side of the foot and dorsolateral surface of the little toe (Fig. 6.128B). The saphenous nerve is a cutaneous branch of the femoral nerve that originates in the thigh. Terminal branches enter the foot in superficial fascia on the medial side of the ankle and supply skin on the medial side of the proximal foot (Fig. 6.128B). Tendons, muscles, and bony landmarks in the lower limb are used to locate major arteries, veins, and nerves.
Anatomy_Gray_1532	Anatomy_Gray	Tendons, muscles, and bony landmarks in the lower limb are used to locate major arteries, veins, and nerves. Because vessels are large, they can be used as entry points to the vascular system. In addition, vessels in the lower limb are farthest from the heart and the most inferior in the body. Therefore, the nature of peripheral pulses in the lower limb can give important information about the status of the circulatory system in general. Sensation and muscle action in the lower limb are tested to assess lumbar and sacral regions of the spinal cord. Avoiding the sciatic nerve	Anatomy_Gray. Tendons, muscles, and bony landmarks in the lower limb are used to locate major arteries, veins, and nerves. Because vessels are large, they can be used as entry points to the vascular system. In addition, vessels in the lower limb are farthest from the heart and the most inferior in the body. Therefore, the nature of peripheral pulses in the lower limb can give important information about the status of the circulatory system in general. Sensation and muscle action in the lower limb are tested to assess lumbar and sacral regions of the spinal cord. Avoiding the sciatic nerve
Anatomy_Gray_1533	Anatomy_Gray	Sensation and muscle action in the lower limb are tested to assess lumbar and sacral regions of the spinal cord. Avoiding the sciatic nerve The sciatic nerve innervates muscles in the posterior compartment of the thigh, muscles in the leg and foot, and an appreciable area of skin. It enters the lower limb in the gluteal region (Fig. 6.129) and passes inferiorly midway between two major palpable bony landmarks, the greater trochanter and the ischial tuberosity. The greater trochanter can be easily felt as a hard bony protuberance about one hand’s width inferior to the midpoint of the iliac crest. The ischial tuberosity is palpable just above the gluteal fold. The gluteal region can be divided into quadrants by two lines positioned using palpable bony landmarks. One line descends vertically from the highest point of the iliac crest.	Anatomy_Gray. Sensation and muscle action in the lower limb are tested to assess lumbar and sacral regions of the spinal cord. Avoiding the sciatic nerve The sciatic nerve innervates muscles in the posterior compartment of the thigh, muscles in the leg and foot, and an appreciable area of skin. It enters the lower limb in the gluteal region (Fig. 6.129) and passes inferiorly midway between two major palpable bony landmarks, the greater trochanter and the ischial tuberosity. The greater trochanter can be easily felt as a hard bony protuberance about one hand’s width inferior to the midpoint of the iliac crest. The ischial tuberosity is palpable just above the gluteal fold. The gluteal region can be divided into quadrants by two lines positioned using palpable bony landmarks. One line descends vertically from the highest point of the iliac crest.
Anatomy_Gray_1534	Anatomy_Gray	The gluteal region can be divided into quadrants by two lines positioned using palpable bony landmarks. One line descends vertically from the highest point of the iliac crest. The other line passes horizontally through the first line midway between the highest point of the iliac crest and the horizontal plane through the ischial tuberosity. The sciatic nerve curves through the upper lateral corner of the lower medial quadrant and descends along the lateral margin of the lower medial quadrant. Injections can be carried out in the anterior corner of the upper lateral quadrant to avoid injury to the sciatic nerve and major vessels in the region (Fig. 6.129B). Finding the femoral artery in the femoral triangle The femoral artery passes into the femoral triangle (Fig. 6.130) of the lower limb from the abdomen.	Anatomy_Gray. The gluteal region can be divided into quadrants by two lines positioned using palpable bony landmarks. One line descends vertically from the highest point of the iliac crest. The other line passes horizontally through the first line midway between the highest point of the iliac crest and the horizontal plane through the ischial tuberosity. The sciatic nerve curves through the upper lateral corner of the lower medial quadrant and descends along the lateral margin of the lower medial quadrant. Injections can be carried out in the anterior corner of the upper lateral quadrant to avoid injury to the sciatic nerve and major vessels in the region (Fig. 6.129B). Finding the femoral artery in the femoral triangle The femoral artery passes into the femoral triangle (Fig. 6.130) of the lower limb from the abdomen.
Anatomy_Gray_1535	Anatomy_Gray	Finding the femoral artery in the femoral triangle The femoral artery passes into the femoral triangle (Fig. 6.130) of the lower limb from the abdomen. The femoral triangle is the depression formed in the anterior thigh between the medial margin of the adductor longus muscle, the medial margin of the sartorius muscle, and the inguinal ligament. The tendon of the adductor longus muscle can be palpated as a cord-like structure that attaches to bone immediately inferior to the pubic tubercle. The sartorius muscle originates from the anterior superior iliac spine and crosses anteriorly over the thigh to attach to the medial aspect of the tibia below the knee joint. The inguinal ligament attaches to the anterior superior iliac spine laterally and the pubic tubercle medially.	Anatomy_Gray. Finding the femoral artery in the femoral triangle The femoral artery passes into the femoral triangle (Fig. 6.130) of the lower limb from the abdomen. The femoral triangle is the depression formed in the anterior thigh between the medial margin of the adductor longus muscle, the medial margin of the sartorius muscle, and the inguinal ligament. The tendon of the adductor longus muscle can be palpated as a cord-like structure that attaches to bone immediately inferior to the pubic tubercle. The sartorius muscle originates from the anterior superior iliac spine and crosses anteriorly over the thigh to attach to the medial aspect of the tibia below the knee joint. The inguinal ligament attaches to the anterior superior iliac spine laterally and the pubic tubercle medially.
Anatomy_Gray_1536	Anatomy_Gray	The inguinal ligament attaches to the anterior superior iliac spine laterally and the pubic tubercle medially. The femoral artery descends into the thigh from the abdomen by passing under the inguinal ligament and into the femoral triangle. In the femoral triangle, its pulse is easily felt just inferior to the inguinal ligament midway between the pubic symphysis and the anterior superior iliac spine. Medial to the artery is the femoral vein and medial to the vein is the femoral canal, which contains lymphatics and lies immediately lateral to the pubic tubercle. The femoral nerve lies lateral to the femoral artery. Identifying structures around the knee	Anatomy_Gray. The inguinal ligament attaches to the anterior superior iliac spine laterally and the pubic tubercle medially. The femoral artery descends into the thigh from the abdomen by passing under the inguinal ligament and into the femoral triangle. In the femoral triangle, its pulse is easily felt just inferior to the inguinal ligament midway between the pubic symphysis and the anterior superior iliac spine. Medial to the artery is the femoral vein and medial to the vein is the femoral canal, which contains lymphatics and lies immediately lateral to the pubic tubercle. The femoral nerve lies lateral to the femoral artery. Identifying structures around the knee
Anatomy_Gray_1537	Anatomy_Gray	Identifying structures around the knee The patella is a prominent palpable feature at the knee. The quadriceps femoris tendon attaches superiorly to it and the patellar ligament connects the inferior surface of the patella to the tibial tuberosity (Fig. 6.131). The patellar ligament and the tibial tuberosity are easily palpable. A tap on the patellar ligament (tendon) tests reflex activity mainly at spinal cord levels L3 and L4. The head of the fibula is palpable as a protuberance on the lateral surface of the knee just inferior to the lateral condyle of the tibia. It can also be located by following the tendon of the biceps femoris inferiorly. The common fibular nerve passes around the lateral surface of the neck of the fibula just inferior to the head and can often be felt as a cord-like structure in this position.	Anatomy_Gray. Identifying structures around the knee The patella is a prominent palpable feature at the knee. The quadriceps femoris tendon attaches superiorly to it and the patellar ligament connects the inferior surface of the patella to the tibial tuberosity (Fig. 6.131). The patellar ligament and the tibial tuberosity are easily palpable. A tap on the patellar ligament (tendon) tests reflex activity mainly at spinal cord levels L3 and L4. The head of the fibula is palpable as a protuberance on the lateral surface of the knee just inferior to the lateral condyle of the tibia. It can also be located by following the tendon of the biceps femoris inferiorly. The common fibular nerve passes around the lateral surface of the neck of the fibula just inferior to the head and can often be felt as a cord-like structure in this position.
Anatomy_Gray_1538	Anatomy_Gray	The common fibular nerve passes around the lateral surface of the neck of the fibula just inferior to the head and can often be felt as a cord-like structure in this position. Another structure that can usually be located on the lateral side of the knee is the iliotibial tract. This flat tendinous structure, which attaches to the lateral tibial condyle, is most prominent when the knee is fully extended. In this position, the anterior edge of the tract raises a sharp vertical fold of skin posterior to the lateral edge of the patella. Visualizing the contents of the popliteal fossa	Anatomy_Gray. The common fibular nerve passes around the lateral surface of the neck of the fibula just inferior to the head and can often be felt as a cord-like structure in this position. Another structure that can usually be located on the lateral side of the knee is the iliotibial tract. This flat tendinous structure, which attaches to the lateral tibial condyle, is most prominent when the knee is fully extended. In this position, the anterior edge of the tract raises a sharp vertical fold of skin posterior to the lateral edge of the patella. Visualizing the contents of the popliteal fossa
Anatomy_Gray_1539	Anatomy_Gray	Visualizing the contents of the popliteal fossa The popliteal fossa is a diamond-shaped depression formed between the hamstrings and gastrocnemius muscle posterior to the knee. The inferior margins of the diamond are formed by the medial and lateral heads of the gastrocnemius muscle. The superior margins are formed laterally by the biceps femoris muscle and medially by the semimembranosus and semitendinosus muscles. The tendons of the biceps femoris muscle and the semitendinosus muscle are palpable and often visible. The head of the fibula is palpable on the lateral side of the knee and can be used as a landmark for identifying the biceps femoris tendon and the common fibular nerve, which curves laterally out of the popliteal fossa and crosses the neck of the fibula just inferior to the head.	Anatomy_Gray. Visualizing the contents of the popliteal fossa The popliteal fossa is a diamond-shaped depression formed between the hamstrings and gastrocnemius muscle posterior to the knee. The inferior margins of the diamond are formed by the medial and lateral heads of the gastrocnemius muscle. The superior margins are formed laterally by the biceps femoris muscle and medially by the semimembranosus and semitendinosus muscles. The tendons of the biceps femoris muscle and the semitendinosus muscle are palpable and often visible. The head of the fibula is palpable on the lateral side of the knee and can be used as a landmark for identifying the biceps femoris tendon and the common fibular nerve, which curves laterally out of the popliteal fossa and crosses the neck of the fibula just inferior to the head.