ExperimentalManualofHumanAnatomyII.BonesoffreelowerlimbThe bones of free lower limb include the femur in the thigh, the patella in the knee, the tibia andfibulaintheleg,and thetarsal bones,themetatarsal bones and thephalangesoftoes in thefoot1.FemurThe femur, the longest and strongest long bone of the body, lies in the thigh. It has an upperend, a lower end and a body or shaft. The upper end consists of a head, a neck, and twotrochanters, the greater and the lesser. The head offemur is a globular projection directingmedially,upwards and slightlyforwards.Thefovea offemoral head is a roughened pit near thecenter ofthe head,towhichthe ligament of femoral head is attached.Theneck of femurconnectsthehead withthe shaft.Atthe junction oftheneck and the shafttherearetwo elevations,thesuperolateral one isthe greater trochanter which is a large quadrangular prominence on itsmedial surface, and the inferomedial one is the lesser trochanter which is a conical eminence.Between the two trochanters, there are the intertrochanteric line anteriorly and theintertrochanteric crest posteriorlyThe bodyor shaft of femur is more or less cylindrical above,prismatic in the middle,andsomewhat flattened below, and it is slightly convex forwards.Theposterior body is a prominentlongitudinal ridge or crest knownas the linea aspera which has a lateral lip and a medial lip.Thelateral lipcontinuessuperolaterallyasthegluteal tuberosity,andthemedial lipcontinuessuperomedially as the pectineal line. Distally, two lips of linea aspera diverge as the medialsupracondylar line and the lateral supracondylar line to enclose the popliteal surfaceThelowerendoffemuriswidelyexpandedtoformtwooblongprominencesknownasthemedialcondyle and the lateral condyle, Anteriorly, two condyles are united to form the patellar surfaceand posteriorly, they are separated by the intercondylar fossa or intercondylar notch. The roughelevation on the medial aspect ofmedial condyle is the medial epicondyle,and that on the lateralaspect of lateral condyle is the lateral epicondyle. The projection posterosuperior to the medialepicondyle is the adductor tubercle31
Experimental Manual of Human Anatomy 31 II. Bones of free lower limb The bones of free lower limb include the femur in the thigh, the patella in the knee, the tibia and fibula in the leg, and the tarsal bones, the metatarsal bones and the phalanges of toes in the foot. 1. Femur The femur, the longest and strongest long bone of the body, lies in the thigh. It has an upper end, a lower end and a body or shaft. The upper end consists of a head, a neck, and two trochanters, the greater and the lesser. The head of femur is a globular projection directing medially, upwards and slightly forwards. The fovea of femoral head is a roughened pit near the center of the head, to which the ligament of femoral head is attached. The neck of femur connects the head with the shaft. At the junction of the neck and the shaft there are two elevations, the superolateral one is the greater trochanter which is a large quadrangular prominence on its medial surface, and the inferomedial one is the lesser trochanter which is a conical eminence. Between the two trochanters, there are the intertrochanteric line anteriorly and the intertrochanteric crest posteriorly. The body or shaft of femur is more or less cylindrical above, prismatic in the middle, and somewhat flattened below, and it is slightly convex forwards. The posterior body is a prominent longitudinal ridge or crest known as the linea aspera which has a lateral lip and a medial lip. The lateral lip continues superolaterally as the gluteal tuberosity, and the medial lip continues superomedially as the pectineal line. Distally, two lips of linea aspera diverge as the medial supracondylar line and the lateral supracondylar line to enclose the popliteal surface. The lower end of femur is widely expanded to form two oblong prominences known as the medial condyle and the lateral condyle, Anteriorly, two condyles are united to form the patellar surface, and posteriorly, they are separated by the intercondylar fossa or intercondylar notch. The rough elevation on the medial aspect of medial condyle is the medial epicondyle, and that on the lateral aspect of lateral condyle is the lateral epicondyle. The projection posterosuperior to the medial epicondyle is the adductor tubercle
ExperimentalManualofHumanAnatomyThegreater trochanter,themedial and lateral epicondyles arepalpable.The upper end of thefemur, especially the neck, is a common site of fracture in elders2.PatellaThe patella is thelargest sesamoid bone in the body,situated in front of the lower end offemurembedded in the tendon of quadriceps femoris. It is triangular in shape, and has an apex, a base.two surfaces, the anterior and posterior, and two borders, the medial and lateral3.TibiaThe tibia is situated in the medial part of the leg.It is a long bone and has a body or shaft and twoends. The upper end is large and expanded from side to side to form the medial condyle and thelateral condyle.The superior articular surfaceoneach condyle is oval ornearlycircular andarticulates withthecorresponding condyleoffemur.Between the articular surfacesis theintercondylar eminence.The tibial tuberosity is a rough prominence located on the anterioraspect of the upper end of tibia, it gives attachment to the patellar ligament. The shaft oftibia isprismatic in shape, and has three borders, anterior, medial and lateral.The lateral border,alsocalled the interosseous border, is thin and prominent, and gives attachment to the interosseousmembrane.On the upper part of posterior surface is a roughridgeknown as the soleal line, whichrunsdownwards andmediallyfromthefibulararticularfacet.The lower end of tibia, much smaller than the upper, is slightly expanded. It is prolongeddownwards from its medial surface as a strong process, called the medial malleolus. The inferiorarticular surfaceofthe lower end and the articular surfaceof medialmalleolus articulatetogetherwith the talus.Thelateral aspect of lower end presents a triangular roughdepression, named as thefibularnotch4.FibulaThe slender fibula is located lateral to the tibia in the leg. It is a long bone and has a body or shaftand two ends. Its upper or proximal end is slightly expanded in all directions toform the head offibula The shaft of fibula is prismatic in shape and has three borders, the anterior, posterior and32
Experimental Manual of Human Anatomy 32 The greater trochanter, the medial and lateral epicondyles are palpable. The upper end of the femur, especially the neck, is a common site of fracture in elders. 2. Patella The patella is the largest sesamoid bone in the body, situated in front of the lower end of femur, embedded in the tendon of quadriceps femoris. It is triangular in shape, and has an apex, a base, two surfaces, the anterior and posterior, and two borders, the medial and lateral. 3. Tibia The tibia is situated in the medial part of the leg. It is a long bone and has a body or shaft and two ends. The upper end is large and expanded from side to side to form the medial condyle and the lateral condyle. The superior articular surface on each condyle is oval or nearly circular and articulates with the corresponding condyle of femur. Between the articular surfaces is the intercondylar eminence. The tibial tuberosity is a rough prominence located on the anterior aspect of the upper end of tibia, it gives attachment to the patellar ligament. The shaft of tibia is prismatic in shape, and has three borders, anterior, medial and lateral. The lateral border, also called the interosseous border, is thin and prominent, and gives attachment to the interosseous membrane. On the upper part of posterior surface is a rough ridge known as the soleal line, which runs downwards and medially from the fibular articular facet. The lower end of tibia, much smaller than the upper, is slightly expanded. It is prolonged downwards from its medial surface as a strong process, called the medial malleolus. The inferior articular surface of the lower end and the articular surface of medial malleolus articulate together with the talus. The lateral aspect of lower end presents a triangular rough depression, named as the fibular notch. 4. Fibula The slender fibula is located lateral to the tibia in the leg. It is a long bone and has a body or shaft and two ends. Its upper or proximal end is slightly expanded in all directions to form the head of fibula. The shaft of fibula is prismatic in shape and has three borders, the anterior, posterior and
Experimental Manualof HumanAnatomymedial, and three surfaces, the medial,posterior and lateral.The medial border is sharp and iscalled the interosseous border. The lower or distal end forms the lateral malleolus, the medialsurface of which bears a triangular articular facet for the talus anteriorly and thelateral malleolarfossaposteriorly7.BonesoffootThe bones of foot include the tarsal bones, metatarsal bones and phalanges oftoes(1)Tarsal bonesThe tarsal bones are seven in number, and are arranged in three rows. The proximal row containsthe talus above and the calcaneus below, the distal row hasfourtarsal bones lying sideby sidefrom medial to lateral side these arethe medial cuneiform, intermediatecuneiform, lateralcuneiform and cuboid bone,and themiddlerowhas onlythenavicularbone,interposedbetweenthe talus and three cuneiform bones. They are short bones, each of them is roughly cuboidal inshape and has six surfaces. The talus is only one that articulates with the bones in the leg. It has ahead, a neck and a body,andrests on the anteriortwo-thirds of the calcaneus.The head is directedforwards and articulates with the calcaneus and navicular bone. The superior, medial and lateralsurfaces of the body are articular, forming the trochlea of talus, which articulates with the lowends ofthetibia andfibulato formtheankle joint.The inferior surfaceof the bodyarticulates withthe calcaneus to form the subtalar joint. The calcaneus is the largest and strongest tarsal bone andis palpable. It articulates with the talus superiorly and with the cuboid anteriorly. The posterioraspect of calcaneus has a prominence called the calcaneal tuberosityThecuboidbone isthe lateral boneofthedistal rowoftarsus, infrontofthe calcaneus,andbehind thefourth andfifthmetatarsal bones.Its inferior orplantarsurfacepresents a deep obliquegroove, the peroneal sulcus. The cuboid articulates with five bones, i. e, the calcaneus, navicular,lateral cuneiform, and thefourthandfifthmetatarsals(2) Metatarsal bones The metatarsal bones are five in number, and are numbered one to fivefrommedial to lateral side. Each metatarsal bone is a long bone and has a base or proximal end, a shaft33
Experimental Manual of Human Anatomy 33 medial, and three surfaces, the medial, posterior and lateral. The medial border is sharp and is called the interosseous border. The lower or distal end forms the lateral malleolus, the medial surface of which bears a triangular articular facet for the talus anteriorly and the lateral malleolar fossa posteriorly. 7. Bones of foot The bones of foot include the tarsal bones, metatarsal bones and phalanges of toes. (1) Tarsal bones The tarsal bones are seven in number, and are arranged in three rows. The proximal row contains the talus above and the calcaneus below, the distal row has four tarsal bones lying side by side, from medial to lateral side these are the medial cuneiform, intermediate cuneiform, lateral cuneiform and cuboid bone; and the middle row has only the navicular bone, interposed between the talus and three cuneiform bones. They are short bones, each of them is roughly cuboidal in shape and has six surfaces. The talus is only one that articulates with the bones in the leg. It has a head, a neck and a body, and rests on the anterior two-thirds of the calcaneus. The head is directed forwards and articulates with the calcaneus and navicular bone. The superior, medial and lateral surfaces of the body are articular, forming the trochlea of talus, which articulates with the low ends of the tibia and fibula to form the ankle joint. The inferior surface of the body articulates with the calcaneus to form the subtalar joint. The calcaneus is the largest and strongest tarsal bone and is palpable. It articulates with the talus superiorly and with the cuboid anteriorly. The posterior aspect of calcaneus has a prominence called the calcaneal tuberosity. The cuboid bone is the lateral bone of the distal row of tarsus, in front of the calcaneus, and behind the fourth and fifth metatarsal bones. Its inferior or plantar surface presents a deep oblique groove, the peroneal sulcus. The cuboid articulates with five bones, i. e, the calcaneus, navicular, lateral cuneiform, and the fourth and fifth metatarsals. (2) Metatarsal bones The metatarsal bones are five in number, and are numbered one to five from medial to lateral side. Each metatarsal bone is a long bone and has a base or proximal end, a shaft
ExperimentalManualofHumanAnatomyand ahead ordistal end.Thebaseofthefifthmetatarsal bone is characterizedbyaprocessnamedthe tuberosity of the fifth metatarsal bone(3)PhalangesoftoesThereare14phalangesof toes ineachfoot.2for thegreattoe,proximal anddistal,and 3foreach oftheother toes,proximal,middleand distalSection 2Joints of lower limbThe articulationsofthelowerLimb includeboththoseofthepelvicgirdleand thoseof thefreelowerlimb.1.Articulations of pelvic girdleThe articulations of the pelvis may be divided into four groups: the joints between the sacrumandthe ilium,thejoints between thehip and spinal column,the joints between the sacrum andthecoccyx, and between the two pubic bones(l)SacroiliacjointIt isformed by the auricular surfaces of the sacrum and the ilium.The irregular articular surfacesof eachbonecontact closely witheach other.The articularcapsuleis verytight and is strengthenedbytheanterior sacroiliac ligament,the posterior sacroiliac ligament and the interosseous sacroiliacligament.Themovements of this joint are very limited because the joint is adapted to support theweight of the body. The joints are somewhat more movable during the later stage of pregnancy asthe ligaments become more lax from hormonal action(2) Ligaments connectingthehipand spinal columnThese ligaments connect the hip bones and the lumbar vertebra, and reinforce the sacroiliac jointThe iliolumbar ligament extends from the front part of the transverse process of the fifth lumbarvertebra to the upper and posterior part of the crest of the ilium. The sacrotuberous ligament is atriangular strongbraceforthe sacroiliac joint,andpassesfromthelateralmargin ofboththe sacrumand coccyx to the medial margin of the ischial tuberosity.The sacroiliac ligament is thin andtriangular, situated at the front of the sacrotuberous ligament It bridges between the lateral margin34
Experimental Manual of Human Anatomy 34 and a head or distal end. The base of the fifth metatarsal bone is characterized by a process named the tuberosity of the fifth metatarsal bone. (3)Phalanges of toes There are 14 phalanges of toes in each foot. 2 for the great toe, proximal and distal, and 3 for each of the other toes, proximal, middle and distal. Section 2 Joints of lower limb The articulations of the lower Limb include both those of the pelvic girdle and those of the free lower limb. 1. Articulations of pelvic girdle The articulations of the pelvis may be divided into four groups: the joints between the sacrum and the ilium; the joints between the hip and spinal column, the joints between the sacrum and the coccyx, and between the two pubic bones. (1) Sacroiliac joint It is formed by the auricular surfaces of the sacrum and the ilium. The irregular articular surfaces of each bone contact closely with each other. The articular capsule is very tight and is strengthened by the anterior sacroiliac ligament, the posterior sacroiliac ligament and the interosseous sacroiliac ligament. The movements of this joint are very limited because the joint is adapted to support the weight of the body. The joints are somewhat more movable during the later stage of pregnancy as the ligaments become more lax from hormonal action. (2) Ligaments connecting the hip and spinal column These ligaments connect the hip bones and the lumbar vertebra, and reinforce the sacroiliac joint. The iliolumbar ligament extends from the front part of the transverse process of the fifth lumbar vertebra to the upper and posterior part of the crest of the ilium. The sacrotuberous ligament is a triangular strong brace for the sacroiliac joint, and passes from the lateral margin of both the sacrum and coccyx to the medial margin of the ischial tuberosity. The sacroiliac ligament is thin and triangular, situated at the front of the sacrotuberous ligament. It bridges between the lateral margin
ExperimentalManualofHumanAnatomyof boththe sacrumand coccyxtothe ischial spine.Thesetwo ligaments covertthesciatic notchesinto the great sciatic foramen and the lesser sciatic foramen(3)SacrococcygealSymphysisThis joint is a cartilaginous joint, formed by the oval surface at the apex of the sacrum and thebase of the coccyx.The movements of the joint areforward and backward and are very limited.Thejoint becomes more movable with the advance of pregnancy.(4) Pubic SymphysisIt is a fibrocartilaginous joint formed by the inter-pubic disc between the two articular surfacesof thepubes.Thedisc may contain a small cavity and is reinforcedby someinconsequentialligaments functionally.(5) PelvisIt is formed by two hip bones united anteriorly with pubic symphysis, and attached posteriorly tothe sacrum and coccyx. It is inclined forward when the body is erect. The terminal line is a circularline formed by the sacra promontory,the anterior border of the sacral ala, the arcuate line of theilium, the pectin pubis, the pubic crest and the upper margin of the symphysis pubis. The pelvis isdivided into a greater (false)pelvis and a lesser (true)pelvis by the terminal line.The greater pelvisis above the terminal line.The pelvic inlet (superior pelvic aperture) of the lesser pelvis issurrounded by the terminal line. The pelvic outlet (inferior pelvic aperture) of the lesser pelvis isbounded by the apex of the coccyx the sacrotuberous and sacrospinous ligaments, the ischialtuberosities,pubic arch and the lower border of thepubic symphysis.Thepubic arch isformedbythe conjoined rami of the pubis and ischium on either side.These archesmeet belowthe pubicsymphysis to form the subpubic angle.The pelvic joints and ligaments are relaxed and capable of more extensive movements duringpregnancy. As the fetal head passes from the pelvic inlet to the outlet, all diameters of the pelviccavity are increased.The movements are possible not only because of the laxity ofthe pelvic jointsbut also because of the stretching of the sacrotuberous and sacrospinous ligaments35
Experimental Manual of Human Anatomy 35 of both the sacrum and coccyx to the ischial spine. These two ligaments covert the sciatic notches into the great sciatic foramen and the lesser sciatic foramen. (3) Sacrococcygeal Symphysis This joint is a cartilaginous joint, formed by the oval surface at the apex of the sacrum and the base of the coccyx. The movements of the joint are forward and backward and are very limited. The joint becomes more movable with the advance of pregnancy. (4) Pubic Symphysis It is a fibrocartilaginous joint formed by the inter-pubic disc between the two articular surfaces of the pubes. The disc may contain a small cavity and is reinforced by some inconsequential ligaments functionally. (5) Pelvis It is formed by two hip bones united anteriorly with pubic symphysis, and attached posteriorly to the sacrum and coccyx. It is inclined forward when the body is erect. The terminal line is a circular line formed by the sacra promontory, the anterior border of the sacral ala, the arcuate line of the ilium, the pectin pubis, the pubic crest and the upper margin of the symphysis pubis. The pelvis is divided into a greater (false) pelvis and a lesser (true) pelvis by the terminal line. The greater pelvis is above the terminal line. The pelvic inlet (superior pelvic aperture) of the lesser pelvis is surrounded by the terminal line. The pelvic outlet (inferior pelvic aperture) of the lesser pelvis is bounded by the apex of the coccyx the sacrotuberous and sacrospinous ligaments, the ischial tuberosities, pubic arch and the lower border of the pubic symphysis. The pubic arch is formed by the conjoined rami of the pubis and ischium on either side. These arches meet below the pubic symphysis to form the subpubic angle. The pelvic joints and ligaments are relaxed and capable of more extensive movements during pregnancy. As the fetal head passes from the pelvic inlet to the outlet, all diameters of the pelvic cavity are increased. The movements are possible not only because of the laxity of the pelvic joints but also because of the stretching of the sacrotuberous and sacrospinous ligaments