Femoral triangle (Figs 8.1—8.8) 100
Anterior and medial aspect of the hip, thigh and knee (Figs 8.9—8.15) 102
Anterior and medial aspect of the thigh 102
Medial aspect of the knee 104
Medical aspect of the flexed knee (Figs 8.16—8.18) 105
Lateral aspect of the hip, thigh and knee (Figs 8.19—8.25) 106
Lateral aspect of the hip 106
Lateral aspect of the knee 106
Lateral aspect of the flexed knee (Figs 8.27—8.30) 109
Posterior aspect of the hip, thigh and knee (Figs 8.31—8.37) 110
Gluteal region 110
Posterior aspect of the thigh 111
Popliteal fossa (Figs 8.38-8.40) 112
Movements of the knee joint 113
Anterior aspect of the lower leg (Figs 8.41—8.46) 114
Anterior aspect of the ankle and foot (Figs 8.47-8.51) 116
Dorsum of the foot 116
Medial aspect of the lower leg (Figs 8.52-8.57) 117
Lateral aspect of the lower leg (Figs 8.58-8.63) 118
Posterior aspect of the lower leg (Figs 8.64-8.71) 120
Movements of the ankle and intertarsal joints (Figs 8.72-8.75) 123
Sole of the foot (Figs 8.76-8.83) 124
Innervation of the lower limb (Figs 8.84-8.87) 126
Vessels of the lower limb (Figs 8.88-8.89) 128
Femoral triangle (Figs 8.1—8.8)
The symphysis, body, crest and tubercle of the pubis, and the anterior superior iliac spine of the pelvis are palpable anteriorly (Fig. 8.3). The inguinal ligament passes between the anterior superior iliac spine and the pubic tubercle, and forms about three-quarters of the base of the femoral triangle (the rest continues across the body of the pubis — Figs 8.6, 8.8). The lateral border of the triangle is formed by the sartorius muscle. This muscle passes from the anterior superior iliac spine distally, across the thigh, to be attached to the medial subcutaneous surface of the upper tibia. Its function is best described as producing the crossed-leg position and it is known as the tailor's muscle; it is supplied by the femoral nerve.
8.1 Femoral triangle
8.2 Femoral triangle: bones
1 Iliac crest
2 Tubercle of ilium
3 Anterior superior iliac spine
4 Superior pubic ramus
5 Pubic tubercle
6 Symphysis pubis
7 Body of pubis
8 Inferior pubic ramus
9 Head of femur
10 Lesser trochanter
8.3 Pelvis and anterior thigh: palpable structures
1 Iliac crest
2 Tubercle of ilium
3 Anterior superior iliac spine
4 Femoral artery
5 Pubic tubercle
6 Symphysis pubis
7 Head of femur
8 Greater trochanter
8.4 Hip and pelvis: anterior view
1 Ilium
2 Superior ramus of pubis
3 Inferior ramus of pubis
4 Ischium
5 Head of femur
6 Neck of femur
7 Greater trochanter
8 Lesser trochanter
9 Shaft of femur
8.5 Femoral triangle: muscle attachments
1 Iliacus
2 Sartorius
3 Rectus femoris, straight head
4 and 15 Iliofemoral ligament
5 Pectineus
6 Adductor longus
7 Obturator externus (from a rim of ischium and pubis, and obturator membrane)
8 Adductor brevis
9 Gracilis
10 Adductor magnus
11 Quadratus femoris
12 Piriformis
13 Gluteus minimus
14 Vastus lateralis
16 Iliopsoas major
17 Vastus medialis
18 Vastus intermedius
8.6 Femoral triangle: muscles
1 Adductor longus
2 Pectineus
3 Iliopsoas
4 Sartorius
8.7 Hip joint: anterior aspect
1 and 2 Iliofemoral ligament
3 Pubofemoral ligament
8.8 Femoral triangle: vessels and nerves
1 Femoral artery
2 Point of access to femoral artery
3 Femoral vein
4 Point of access to femoral vein
5 Femoral canal
6 Femoral nerve
7 Saphenous opening
8 Great saphenous vein
9 Horizontal and
10 Vertical groups of inguinal nodes
The medial border of the triangle is the medial aspect of the adductor longus muscle passing from the body of the pubis to the linea aspera of the femur; it is supplied by the obturator nerve. The roof of the triangle is formed of fascia lata, which surrounds the thigh like a stocking and is attached superiorly to the inguinal ligament, the iliac crest, the inferior pubic ramus and the sacrum. The saphenous opening in the fascia is 4 cm below and just lateral to the pubic tubercle, overlying the femoral vein and transmitting its great saphenous tributary.
The floor of the triangle is formed by the iliopsoas and pectineus muscles which lie anterior to the hip joint; the head of the femur can be felt deeply in the triangle. The iliopsoas muscle is attached proximally to the medial aspect of the ilium and to the lateral aspect of the lumbar vertebrae. Distally, the tendon passes to the lesser trochanter of the femur; it is a powerful flexor and medial rotator of the hip joint and is supplied from the lumbar plexus through the second and third roots. The pectineus muscle is attached to the superior pubic ramus and, distally, just below the iliopsoas tendon on the femur, it is supplied by the femoral nerve.
The femoral artery descends vertically through the triangle from the midinguinal point (midway between the anterior superior iliac spine and the symphysis pubis) to the apex of the triangle. Its deep (profunda) branch passes posteriorly, between the adductor longus and the pectineus muscles.
The femoral vein lies medial to the artery within a common sheath and with the femoral canal further medially. The femoral nerve lies lateral to the artery, outside the femoral sheath.
The femoral artery is an important site for vascular access and a large number of arteriographic procedures are undertaken through its percutaneous puncture. The femoral vein is also a useful site for venous sampling when other superficial veins, such as those over the cubital fossa, are ill-defined. The femoral artery is prone to arterial disease and the vessel is approached for surgical procedures through a longitudinal incision over the vessel in the femoral triangle.
The inguinal region is examined routinely for lymph node enlargement. Inguinal lymph nodes may be enlarged as part of a generalised disease or secondary to disease of the lower limb. Upper and lower (horizontal/vertical) superficial inguinal groups are situated below and parallel to the inguinal ligament, and around the terminal few centimetres of the great saphenous vein, respectively. They drain to the deep inguinal lymph nodes in the femoral canal and thence to the external iliac nodes. Maldevelopment of the lower limb lymphatics may give rise to inadequate drainage of the limb; the swelling produced is termed lymphoedema.
Anterior and medial aspect of the hip, thigh and knee (Figs 8.9—8.15)
Anterior and medial aspect of the thigh
The anterior aspect of the thigh is formed mainly of the large quadriceps muscle mass (Fig. 8.13). The quadriceps has four proximal attachments: the rectus femoris is attached by a straight head to the anterior inferior iliac spine, and by an oblique head to just above the acetabulum. The vastus lateralis and medialis take their attachment from their respective sides of the intertrochanteric line, encircle the subtrochanteric femur, then converge to their respective sides of the linea aspera of the femur and the vastus intermedialis from the anterior aspect of the femoral shaft. The quadriceps muscle is attached inferiorly to the patella and is extended beyond it to form a strong tendon, the patellar ‘ligament’, attached to the tibial tuberosity. The patella is subcutaneous and easily palpable, as is the tibial tuberosity.
8.9 Anterior and medial aspect of the thigh
8.10 Anterior and medial aspect of the thigh: bones
1 Symphysis pubis
2 Body of pubis
3 Inferior pubic ramus
4 Femur
5 Adductor tubercle
6 Medial femoral condyle
7 Patella
8 Tibial plateau
9 Tibial tuberosity
8.11 The knee joint: anterior view
1 Femoral shaft
2 Upper border of patella
3 Medial femoral condyle
4 Joint space of the knee
5 Lateral tibial condyle
6 Tibial shaft
7 Head of fibula
8.12 Anterior and medial aspect of thigh: muscle attachments
1 Sartorius
2 Rectus femoris, straight head
3 Gluteus minimus
4 Vastus lateralis
5 Vastus medialis
6 Iliopsoas
7 Vastus intermedius
8.13 Anterior and medial aspect of the thigh: superficial (right limb) and deep (left limb) muscles
(Items 6–10 make up the quadriceps muscle)
1 Iliopsoas
2 Pectineus
3 Adductor longus
4 Sartorius
5 Tensor fascia lata
6 Rectus femoris
7 Vastus lateralis
8 Vastus medialis
9 Vastus intermedius
10 Patellar tendon
11 Obturator externus
12 Adductor brevis
13 Adductor magnus
14 Adductor hiatus
8.14 Knee joint: anterior aspect
1 Tendon of quadriceps
2 Ligamentum patellae
3 Lateral patellar retinaculum
4 Medial patellar retinaculum
5 Medial collateral ligament
6 Lateral collateral ligament
8.15 Anterior and medial aspect of thigh: superficial structures
1 Tensor fascia lata
2 Iliopsoas
3 Sartorius
4 Adductor magnus
5 Rectus femoris
6 Gracilis
7 Vastus lateralis
8 Vastus medialis
9 Iliotibial tract
On each side of the patellar ligament, the capsule of the joint is formed largely of downward fibrous expansions of the quadriceps tendon known as retinacula, through which the muscle gains attachment to the tibial condyles. The muscle is supplied by the femoral nerve. The proximal components of the quadriceps are not easily demonstrated when recumbent, or during easy standing, but are clearly seen when the whole leg, with extended knee, is raised against gravity; the patellar ligament and the lower horizontal fibres of the vastus medialis, passing to the medial aspect of the patella, are visible. The latter fibres quickly waste away with inactivity. The medial and lateral femoral condyles and the upper margin of the tibia can be palpated over most of the anterior, medial and lateral aspects of the knee joint (Figs 8.15, 8.30, pp. 105, 109).
The medial side of the thigh contains the adductor group of muscles. The first layer, the pectineus and the adductor longus, has been described in the femoral triangle; the adductor brevis passes from the inferior pubic ramus to the linea aspera between these muscles and the more deeply placed powerful adductor magnus (Fig. 8.13). The latter is attached medially along the ischiopubic ramus and ischial tuberosity and, laterally, to the length of the linea aspera and the medial supracondylar ridge and by a strong tendon to the adductor tubercle on the femur. The tubercle is palpable. The femoral vessels pass through a defect (the adductor hiatus) in this asperal attachment close to the femur; at this point they become the popliteal vessels. The opening is approximately 10 cm above the knee joint. The adductor muscles are overlain by the gracilis muscle, a thin flat (gracile) muscle passing from the inferior pubic ramus to the upper medial aspect of the tibia. The gracilis and the adductor muscles adduct the hip joint and are supplied by the obturator nerve. The adductor magnus also has a sciatic nerve supply to that part arising from the ischial tuberosity; this is functionally and developmentally a part of the hamstring muscle group extending the hip joint.
Medial aspect of the knee
The medial collateral ligament of the knee joint is a wide, flat, strong sheet blending with the capsule of the joint, passing from the medial epicondyle of the femur to the upper surface of the tibial shaft (Fig. 8.17). The medial edge of the medial meniscus is between the femoral and tibial condyles; although it is normally impalpable, if damaged, tenderness can be noted along the joint line and there may be a protrusion over the site of a tear. The tendons of the sartorius, gracilis and semitendinosus are attached to the subcutaneous upper surface of the tibia, from anterior to posterior; they are more easily defined with the knee flexed to a right angle.
Medical aspect of the flexed knee (Figs 8.16—8.18)
8.16 Medial aspect of the flexed knee
8.17 Medial aspect of the flexed knee: bones and muscles
1 Medial femoral condyle
2 Medial tibial condyle
3 Medial meniscus
4 Sartorius
5 Gracilis
6 Adductor magnus
7 Semimembranosus
8 Semitendinosus
9 Medial collateral ligament
10 Vastus medialis
11 Rectus femoris
8.18 Medial aspect of knee: palpable structures
1 Patella
2 Medial femoral condyle
3 Medial tibial condyle
4 Subcutaneous anterior border of tibia
Lateral aspect of the hip, thigh and knee (Figs 8.19—8.25)
Lateral aspect of the hip
The greater trochanter is palpable on the upper lateral aspect of the thigh: it lies posterior and distal to the anterior superior iliac spine.
8.19 Lateral aspect of the hip joint
8.20 Lateral aspect of the hip joint: bones
1 Ilium
2 Anterior superior iliac spine
3 Anterior inferior iliac spine
4 Posterior superior iliac spine
5 Posterior inferior iliac spine ABC, Bryant's triangle
6 Ischial spine
7 Iliopubic eminence
8 Body of pubis
9 Head of femur
10 Greater trochanter
11 Shaft of femur
8.21 Lateral aspect of hip joint: palpable structures
1 Anterior superior iliac spine
2 Iliac crest
3 Posterior superior iliac spine
4 Symphysis pubis
5 Greater trochanter
8.22 Hip joint: oblique view
1 Ilium
2 Ischial spine
3 Ischial tuberosity
4 Head of femur
5 Greater trochanter
6 Lesser trochanter
8.23 Lateral aspect of the hip joint: muscle attachments
1 Tensor fascia lata
2 Sartorius
3 Rectus femoris, straight and oblique heads
4 and 7 Gluteus medius
5 and 8 Gluteus minimus
6 and 11 Gluteus maximus
9 Vastus lateralis
10 Vastus intermedius
8.24 Lateral aspect of the hip joint: superficial muscles
1 Gluteus maximus
2 Tensor fascia lata
3 Gluteus medius
4 Sartorius
5 Rectus femoris
6 Vastus lateralis
7 Long head of biceps femoris
8 Semitendinosus
9 Iliotibial tract
8.25 Lateral aspect of the hip joint: deep muscles and ligaments
1 Sacrotuberous ligament
2 Sacrospinous ligament
3 Piriformis
4 Gluteus minimus
5 Iliopsoas
6 Vastus lateralis
When sitting, the body weight is taken on the ischial tuberosities and is cushioned by the mass of the gluteus maximus and the fatty tissues of the buttock.
In fractures of the neck of the femur the distance BC in the triangle shown in Figure 8.20 (Bryant's triangle) is shortened and this can be demonstrated by comparing the normal and fractured sides.
Fractures of the neck of the femur are common in the elderly, particularly after a fall and often after seemingly minor trauma. Severe trauma can produce fractures of the femoral shaft and, if directed along the length of the femur, such as in motorcycle accidents, it can produce posterior dislocation of the hip joint. In the latter case, the posterior rim of the acetabulum is usually fractured and the sciatic nerve may be damaged. Knee fractures are usually due to direct trauma. They involve the femoral and tibial condyles, and may traverse the articular surfaces of the joint. Torsion injuries can damage the collateral ligaments and the intra-articular menisci.
Lateral aspect of the knee
The biceps tendon can be clearly defined over the lateral aspect of the knee when the knee is flexed to a right angle; the tendon can be followed to its attachment to the upper end of the fibula (Figs 8.29, 8.30 and 8.62, pp. 109, 120). The bony margin of the lateral aspect of the tibial condyle can be palpated and the fibular (lateral collateral) ligament felt as a firm cord, separate from the joint capsule, passing from the lateral aspect of the femoral condyle to the head of the fibula. The lateral meniscus lies adjacent to the tibial margin and becomes tender and sometimes palpable when damaged. The common peroneal nerve is overlapped by the tendon of the biceps and then passes subcutaneously over the neck of the fibula, where it can be palpated, before it divides into deep and superficial branches that enter the anterior and lateral compartments of the leg, respectively.
Lateral aspect of the flexed knee (Figs 8.27—8.30)
8.26 Lateral aspect of the hip joint: superficial structures
1 Gluteus medius
2 Tensor fascia lata
3 Gluteus maximus
4 Iliotibial tract
5 Sartorius
6 Vastus lateralis
7 Hamstring muscles
8.27 Lateral aspect of the flexed knee
8.28 Knee: lateral view
1 Femoral shaft
2 Patella
3 Femoral condyles
4 Tibial condyle
5 Shaft of tibia
6 Shaft of fibula
8.29 Lateral aspect of the flexed knee: bones and soft tissues
1 Lateral femoral condyle
2 Lateral meniscus
3 Lateral tibial condyle
4 Head of fibula
5 Lateral collateral ligament
6 Rectus femoris
7 Vastus lateralis
8 Iliotibial tract
9 Biceps femoris
10 Common peroneal nerve
8.30 Lateral aspect of flexed knee: palpable structures
1 Patella
2 Lateral femoral condyle
3 Lateral tibial condyle
4 Head of fibula
5 Common peroneal nerve
Posterior aspect of the hip, thigh and knee (Figs 8.31—8.37)
Gluteal region
The prominence of the buttock is formed from a large quadrilateral muscle, the gluteus maximus, covered by a variable, thick and even more extensive layer of fibrofatty superficial fascia. The muscle has an extensive proximal attachment, including the lateral surface of the ilium behind the posterior gluteal line, the sacrum, the coccyx and the sacrotuberous ligament. Fibres pass downwards and laterally to the iliotibial tract and the gluteal tuberosity on the femur. The muscle is a powerful lateral rotator and extensor of the hip joint and, through the iliotibial tract, it extends and stabilises the knee joint. The lower border of gluteus maximus does not correspond to the horizontal gluteal fold; the latter is the ‘extensor line’ or posterior skin fold, associated with the hip joint.
8.31 Gluteal region and posterior aspect of the thigh
8.32 Gluteal region and posterior aspect of the thigh: bones
1 Fourth lumbar spine
2 Sacrum
3 Coccyx
4 Iliac crest
5 Posterior superior iliac spine
6 Posterior inferior iliac spine
7 Greater sciatic notch
8 Ischial spine
9 Lesser sciatic notch
10 Ischial tuberosity
11 Head of femur
12 Greater trochanter
13 Lesser trochanter
14 Gluteal tuberosity
15 Linea aspera
16 Adductor tubercle
17 Medial femoral condyle
18 Lateral femoral condyle
19 Medial and lateral supracondylar ridges
8.33 Gluteal region and posterior aspect of thigh: palpable structures
1 Posterior superior iliac spine
2 Coccyx
3 Ischial tuberosity
4 Greater trochanter
5 Medial and lateral femoral condyles
6 Medial and lateral tibial condyles
8.34 Gluteal region and posterior aspect of the thigh: muscle attachments
1 Gluteus medius
2 Hamstring muscles
3 Gluteus maximus
4 Iliopsoas
5 Pectineus
6 Vastus lateralis
7 Adductor brevis
8 Adductor longus
9 Short head of biceps femoris
10 Vastus medialis
11 Adductor magnus
12 and 13 Gastrocnemius
8.35 Gluteal region and posterior aspect of the thigh: superficial (left limb) and deep (right limb) muscles
1 Tensor fascia lata
2 Gluteus maximus
3 Long head of biceps femoris
4 Semitendinosus
5 Semimembranosus
6 Adductor magnus
7 Gracilis
8 Adductor hiatus
9 Sacrotuberous ligament
10 Sacrospinous ligament
11 Gluteus medius
12 Gluteus minimus (deep to medius)
13 Piriformis
14 Quadratus femoris
15 Sciatic nerve
16 Short head of biceps
8.36 Gluteal region and posterior thigh: superficial structures
1 Gluteus medius
2 Tensor fascia lata
3 Gluteus maximus
4 Iliotibial tract
5 Gracilis
6 Biceps
7 Semitendinosus overlying semimembranosus
8.37 Hip joint: posterior aspect
1 Sacrum
2 Coccyx
3 Ischial spine
4 Ischial tuberosity
5 Ischiofemoral ligament
6 Neck of femur
7 Greater trochanter
8 Lesser trochanter
9 Gluteal tuberosity
Gluteus maximus is supplied by the inferior gluteal nerve. The muscle overlies the hip joint and short articular muscles and the nerves leave the pelvis through the greater and lesser sciatic foramina, in particular the sciatic, gluteal and pudendal nerves. Injections into the buttock must be placed in the upper outer quadrant to avoid damage to these deep structures. The tensor fasciae lata is attached to the anterior quarter of the outer lip below the crest of the ilium and is distally attached to the iliotibial tract, acting with gluteus maximus, and stabilising and extending the knee joint. It is supplied by the superior gluteal nerve.
When standing on one leg, the non-weight-bearing side of the pelvis is raised to keep the non-weight-bearing leg off the ground. This action is brought about by the gluteus medius and minimus muscles attached to the anterolateral aspect of the ilium medially, and the greater trochanter laterally. They are supplied by the superior gluteal nerve and may be felt contracting through the gluteus maximus in this position.
Posterior aspect of the thigh
The muscle bulk of the posterior aspect of the thigh is formed from the hamstring muscles arising from the ischial tuberosity (Figs. 8.34, 8.35). The semimembranosus is attached distally to a groove on the posteromedial aspect of the tibial condyle; and also by a tendinous expansion to the lateral femoral condyle (oblique popliteal ligament) and downwards to the soleal line of the tibia, forming the popliteal fascia over the popliteus muscle. Semitendinosus is attached distally to the upper subcutaneous medial surface of the tibia and the biceps to the head of the fibula; the latter muscle receives an additional short head from the linea aspera. The hamstring muscles are powerful extensors of the hip joint and flexors of the knee joint; they are supplied by the sciatic nerve. The biceps (laterally) and the semimembranosus and semitendinosus (medially) form an inverted V bordering the upper part of the popliteal fossa.
The sciatic nerve leaves the pelvis through the greater sciatic foramen and is related to the ischium and the small posterior articular muscles of the hip joint. It passes deep to the gluteus maximus and then the hamstring muscles before dividing into tibial and common peroneal terminal branches.
It may be damaged in posterior dislocation of the hip joint because of its close relation to the joint.
Popliteal fossa (Figs 8.38-8.40)
The popliteal fossa is a diamond-shaped space behind the knee joint. The upper palpable margins are formed by the hamstring tendons and the lower margins by the medial and lateral heads of the gastrocnemius muscle. The fossa is roofed by the popliteal fascia, a thickening of the fascia lata; the floor is formed, from above downwards, by the posterior surface of the femur, the knee joint and the popliteus muscle over the upper tibia.
8.38 Popliteal fossa
8.39 Popliteal fossa: soft tissues
(For the sake of clarity, the popliteal vein, which descends between the popliteal artery and the tibial nerve, has been omitted)
1 Biceps femoris
2 Semimembranosus (on either side of semitendinosus tendon)
3 Semitendinosus
4 Gracilis
5 Sartorius
6 Gastrocnemius, medial head
7 Gastrocnemius, lateral head
8 Adductor hiatus
9 Popliteal artery
10 Anterior tibial artery
11 Peroneal artery
12 Posterior tibial artery
13 Tibial nerve
14 Common peroneal nerve
8.40 Knee joint: posterior aspect
1 and 2 Gastrocnemius
3 Popliteus
4 Lateral collateral ligament
5 Posterior capsule
6 Oblique popliteal ligament
7 Medial collateral ligament
The fossa contains the popliteal vessels and the tibial and common peroneal nerves, fat and a few lymph nodes. The popliteal artery is deep to its vein and closely applied to the knee joint. It can be felt by deep compression along the length of the fossa, but most easily with the knee slightly flexed over the upper tibia.
Movements of the knee joint
The movements of the knee joint are flexion, extension and a little rotation. Flexion is by the hamstring muscles aided by gastrocnemius and limited by the approximation of the calf and thigh. Extension is by the quadriceps and the iliotibial tract muscles. The femoral condyles roll and also glide backwards on the tibial condyles until the cruciate ligaments become taut. Further extension (hyperextension) is brought about by medial rotation of the femur on the tibia around a taut anterior cruciate ligament. When this rotation is also limited by the oblique popliteal ligament, the knee is said to be locked.
Unlocking of the knee, to initiate flexion, is by rotation of the femur laterally on the tibia, this being brought about by the popliteus muscle. The muscle passes from the upper posterior surface of the tibia to both the lateral femoral condyle and the lateral meniscus. The muscle pulls the meniscus free of the joint, preventing it from being crushed between the tibial and femoral condyles during unlocking. The popliteus muscle is supplied by the tibial nerve. Bony surfaces contribute little to the stability of the knee joint; this is dependent on powerful muscles and ligaments. The cruciate ligaments, passing between the tibia and femoral intercondylar regions, limit anteroposterior gliding and distraction of the bones.
Anterior aspect of the lower leg (Figs 8.41—8.46)
The muscles of the lower leg are divided into anterior, lateral and posterior groups by the tibia, the fibula, the interosseous membrane and the anterior and posterior intermuscular septa, which pass from the fascia lata to the fibula. The anterior intermuscular septum divides the anterior (dorsiflexor and long digital extensor) muscles from the lateral (evertor) compartment. The tibia is almost wholly subcutaneous along its anterior border and medial surface, the border extending from the tibial tuberosity and the surface from the medial condyle, and both to the medial malleolus. Of the four muscles of the anterior compartment, only the tibialis anterior is attached to the tibia, this being over the upper two-thirds of the lateral surface and adjacent interosseous membrane (Fig. 8.45). Its distal tendon passes to the medial cuneiform and the base of the first metatarsal bones.
8.41 Anterior aspect of the lower leg
8.42 Anterior aspect of the lower leg: bones
1 Tibia
2 Fibula
3 Medial malleolus
4 Lateral malleolus
5 Talus
6 First metatarsal
7 Fifth metatarsal
8.43 Anterior aspect of lower leg: palpable structures
1 Medial femoral condyle
2 Lateral femoral condyle
3 Patella
4 Medial tibial condyle
5 Lateral tibial condyle
6 Head of fibula
7 Tibial tuberosity
8 Subcutaneous border and surface of tibia
9 Medial malleolus
10 Lateral malleolus
11 Anterior tibial artery
12 Perforating peroneal artery
13 Dorsalis pedis artery
8.44 Anterior aspect of the lower leg: muscle attachments
1 Biceps
2 Peroneus longus
3 Extensor digitorum longus
4 Extensor hallucis longus
5 Peroneus brevis
6 Peroneus tertius
7 Semimembranosus
8 Ligamentum patellae
9 Sartorius
10 Gracilis
11 Semitendinosus
12 Tibialis anterior
13 Iliotibial tract
8.45 Anterior aspect of the lower leg: muscles
1 Tibialis anterior
2 Extensor hallucis longus
3 Extensor digitorum longus
4 Peroneus tertius
5 Superior extensor retinaculum
6 Dorsalis pedis artery
7 First dorsal metatarsal artery
8 Peroneal muscles
8.46 Anterior aspect of right lower leg: superficial structures
1 Quadriceps tendon
2 Iliotibial tract
3 Patellar tendon
4 Tibialis anterior
5 Peroneal muscles
6 Gastrocnemius, medial head
7 Soleus
8 Extensor hallucis longus
9 Extensor digitorum longus
The proximal attachment to the extensor hallucis longus is from the middle half of the fibula and interosseous membrane and the extensor digitorum, the upper two-thirds of the fibula and adjacent intermuscular septum. The tendons pass to the base of the distal phalanges of the toes, those of extensor digitorum longus passing to the lateral four toes, forming extensor expansions similar to those described in the hand (Fig. 7.58, p. 87). The peroneus tertius is a small muscle passing between the lower fibula and the body of the fifth metatarsal. The muscles of the anterior compartment dorsiflex the ankle and, in addition, the extensor hallucis longus and the extensor digitorum longus dorsiflex (extend) the toes; all four muscles are supplied by the deep peroneal nerve.
The two extensor retinaculae lie across the tendons of the anterior muscle group in the lower part of the leg and in front of the ankle joint. The superior is a thickening of the deep fascia between the tibia and fibula, 3 cm above the ankle. The stem of the bifurcate inferior retinaculum passes from the upper calcaneus across the ankle: the upper limb passes to the medial malleolus and the lower blends with the plantar fascia. Tibialis anterior and extensor hallucis longus have separate synovial sheaths beneath the inferior retinaculum. That of the former muscle extends proximally under the superior retinaculum. Extensor digitorum longus and peroneus tertius have a common synovial sheath.
The anterior tibial artery crosses the anterior aspect of the ankle joint approximately midway between the medial and lateral malleoli, with the tibialis anterior and extensor hallucis longus tendons medially and the extensor digitorum and peroneus tertius tendons laterally. The artery becomes the dorsalis pedis at this point and then passes distally, lateral to the tendon of extensor hallucis longus, before passing between the heads of the first dorsal interosseous muscle at the proximal end of the first intermetatarsal space, into the sole. The artery is continued distally as the first dorsal metatarsal artery. The artery can be palpated by pressing it backwards onto the talus, navicular or intermediate cuneiform bones in this region. A perforating branch of the peroneal artery can occasionally be felt descending over the anterior aspect of the lateral malleolus.
Anterior aspect of the ankle and foot (Figs 8.47-8.51)
Dorsum of the foot
On the dorsum of the foot the tubercle of the navicular (medially) and the tuberosity (styloid process) on the base of the fifth metatarsal bone (laterally) are prominent landmarks (Fig. 8.48). The distal row of tarsals, the metatarsals and the phalanges are palpable between the dorsal tendons. The extensor digitorum brevis is the only short muscle on the dorsum of the foot and it extends from the anterior upper surface of the calcaneus; the medial of its four tendons crosses the dorsalis pedis artery and is attached to the base of the proximal phalanx of the great toe (Fig. 8.51). The other tendons join the lateral aspect of the extensor digitorum tendons of the second, third and fourth toes. The muscle dorsiflexes the medial four toes and is supplied by the deep peroneal nerve.
8.47 Dorsum of the foot
8.48 Dorsum of the foot: bones
1 Calcaneus
2 Talus
3 Navicular
4 Tubercle of navicular bone
5 Cuboid
6 Lateral cuneiform
7 Intermediate cuneiform
8 Medial cuneiform
9 Metatarsals
10 Tuberosity (styloid process) of fifth metatarsal bone
11 Proximal phalanges
12 Middle phalanx
13 Distal phalanges
8.49 Ankle: anterior view
1 Shaft of tibia
2 Shaft of fibula
3 Medial malleolus
4 Lateral malleolus
5 Talus
8.50 Dorsum of the foot: muscle attachments
1 Extensor digitorum brevis
2 Peroneus brevis
3 First dorsal interosseus
4 Abductor hallucis
5 Extensor hallucis brevis
6 Extensor hallucis longus
8.51 Dorsum of the foot: tendons
1 Tibialis anterior
2 Extensor hallucis longus
3 Extensor digitorum longus
4 Peroneus tertius
5 Extensor digitorum brevis
6 Extensor tendons
7 Peroneus brevis
8 Dorsalis pedis artery
9 First dorsal metatarsal artery
Medial aspect of the lower leg (Figs 8.52-8.57)
The medial surface of the tibia is subcutaneous throughout its length and is prone to trauma, ranging from superficial cuts to fractures of the bone. The lower end of the bone is expanded into the medial malleolus, articulating with the talus on its lateral side (Fig. 8.53). The posterior medial aspect of the calcaneus, the sustentaculum tali, the tubercle of the navicular, and the medial aspect of the first metatarsal and its two phalanges are palpable along the medial aspect of the foot (for relative positions see Figs 8.52, 8.53).
8.52 Medial aspect of the lower leg and foot
8.53 Medial aspect of the lower leg and foot: bones
1 Tibia
2 Medial malleolus
3 Talus
4 Calcaneus
5 Medial tubercle of calcaneus
6 Sustentaculum tali
7 Navicular (tubercle)
8 Medial cuneiform
9 First metatarsal
10 Phalanges
8.54 Medial aspect of lower leg and foot: palpable structures
1 Patella
2 Medial tibial condyle
3 Subcutaneous border and anterior surface of tibia
4 Medial malleolus
5 Posterior tibial artery
6 Sustentaculum tali
7 Tubercle of navicular
8 Calcaneal tuberosity
9 Head of first metatarsal
8.55 Medial aspect of the lower leg and foot: muscles
1 Sartorius
2 Gracilis
3 Semitendinosus
4 Gastrocnemius
5 Soleus
6 Tibialis posterior
7 Flexor digitorum longus
8 Posterior tibial artery (dotted)
9 Flexor hallucis longus
10 Flexor retinaculum
11 Tibialis anterior
8.56 Ankle joint: medial aspect
1 Medial ligament
2 Posterior tibiotalar ligament
3 Anterior ligament
4 Plantar calcaneonavicular ligament
5 Long plantar ligament
8.57 Medial aspect of lower leg and foot: superficial structures
1 Patellar tendon
2 Medial head of gastrocnemius
3 Soleus
4 Muscles of anterior compartment of leg
5 Tendon of tibialis anterior
The sartorius, gracilis and semitendinosus muscles are attached to the upper subcutaneous surface of the tibia. The tendons of the deep posterior muscles of the calf groove the lower end of the tibia; these are not all palpable but the tibialis posterior, and flexor digitorum longus lateral to it, can be felt just above and medial to the posterior tibial artery. The surface marking of the artery at the ankle joint is between the prominence of the medial malleolus and the medial prominence of the calcaneus. It can be palpated by compression on the talus before it passes deeply into the sole. The deep tendons are covered by a deep thickening in the fascia, the flexor retinaculum; it passes between the medial malleolus and the medial tubercle of the calcaneus. Each tendon has a separate sheath deep to the retinaculum.
On deep pressure about 2 cm below the tip of the medial malleolus, the sustentaculum tali can be felt and is a good clinical landmark for the tendons. Tibialis posterior curves downwards and forwards above the sustentaculum; flexor digitorum longus crosses its medial surface, sometimes grooving it; flexor hallucis longus lies in a deep groove on the inferior aspect (below) of the sustentaculum.
Lateral aspect of the lower leg (Figs 8.58-8.63)
The head of the fibula is palpable below the knee joint but its shaft is surrounded by muscle bellies. The lower end of the bone is expanded into the lateral malleolus; this is 1cm lower than the medial and contributes to the mortise of the ankle joint. The lateral surface of the calcaneus, its peroneal tubercle, the cuboid and the tuberosity (styloid) of the base of the fifth metatarsal are readily palpable along this surface (Fig. 8.59, 60). The two lateral (evertor) compartment muscles are the peroneus longus and peroneus brevis, attached respectively to the upper two-thirds and lower third of the lateral surface of the fibula (Fig. 8.62). The palpable tendons pass behind the lateral malleolus (the peroneus brevis muscle and tendon are anterior) and cross the lateral surface of the calcaneus, above (brevis) and below (longus) the peroneal tubercle.
8.58 Lateral aspect of the lower leg and foot
8.59 Lateral aspect of the lower leg and foot: bones
1 Tibia
2 Head of fibula
3 Lateral malleolus
4 Talus
5 Calcaneus
6 Peroneal tubercle of calcaneus
7 Cuboid
8 Fifth metatarsal
9 Phalanges
8.60 Lateral aspect of lower leg and foot: palpable structures
1 Patella
2 Lateral femoral condyle
3 Lateral tibial condyle
4 Tibial tuberosity
5 Head of fibula
6 Common peroneal nerve
7 Lateral malleolus
8 Calcaneal tuberosity
9 Peroneal tubercle
10 Cuboid
11 Tuberosity of 5th metatarsal
8.61 Ankle: lateral view
1 Overlapping shafts of tibia and fibula
2 Talus
3 Calcaneus
4 Navicular
8.62 Lateral aspect of the lower leg and foot: muscles
1 Iliotibial tract
2 Lateral collateral ligament
3 Biceps femoris tendon
4 Common peroneal nerve
5 Gastrocnemius
6 Soleus
7 Peroneus longus
8 Peroneus brevis
9 Extensor digitorum longus
10 Tibialis anterior
11 and 13 Superior extensor retinaculum
12 Inferior extensor retinaculum
8.63 Ankle joint: lateral aspect
1 Calcaneofibular ligament
2 Posterior talofibular ligament
3 Anterior talofibular ligament
4 Anterior tibiofibular ligament
5 Posterior tibiofibular ligament
The peroneus longus tendon grooves the under surface of the cuboid and is attached to the base of the first metatarsal and adjacent medial cuneiform bone. The tendon of the peroneus brevis passes to the tuberosity of the base of the fifth metatarsal bone. The two muscles evert and plantarflex the foot; they are supplied by the superficial peroneal nerve. The tendons are bound down to the lateral malleolus and calcaneus by two thickenings in the deep fascia, the superior and inferior peroneal retinaculae. The tendons are enclosed in a common synovial sheath which is prolonged over each to its distal attachment.
Lower leg fractures usually involve both the tibia and fibula and, in view of the subcutaneous position of the tibia, these fractures are usually compound (i.e. open to the air, through the intervening skin laceration).
Rotational injuries of the ankle are common and usually involve the lateral and medial ligaments. In more severe injuries, the lateral and medial malleoli may be fractured, and in major trauma, the posterior rim of the tibia (posterior malleolus) is also fractured, and the ankle joint dislocated.
Posterior aspect of the lower leg (Figs 8.64-8.71)
The bulk of the calf is formed of the gastrocnemius and soleus muscles which unite inferiorly to form the tendo calcaneus to be attached to the middle of the posterior surface of the calcaneus (Fig. 8.68). A bursa and a pad of fat separate the tendon from the upper posterior calcaneal surface. The gastrocnemius is superficial to the soleus and it has medial and lateral heads attached to the respective femoral condyles. The soleus has a continuous upper attachment from the head of the fibula, a tendinous arch over the posterior tibial vessels and tibial nerve, and to the soleal line on the tibia. It bulges out on either side of the gastrocnemius in the calf. These muscles are powerful plantar flexors of the foot and are important in both posture and locomotion; they are supplied by the tibial nerve. Within and between the muscles is a plexus of veins, and contraction of the muscles expels blood proximally (the muscle pump). The plantaris is a thin vestigial muscle along the lateral head of the gastrocnemius. The deep muscles of the calf are impalpable above the ankle region.
8.64 Posterior aspect of the lower leg and heel
8.65 Posterior aspect of the lower leg and heel: bones
1 Tibia
2 Fibula
3 Medial malleolus
4 Lateral malleolus
5 Talus
6 Calcaneus
8.66 Posterior aspect of lower leg and heel: palpable structures
1 Lateral femoral condyle
2 Medial femoral condyle
3 Medial tibial condyle
4 Head of fibula
5 Popliteal artery
6 Medial malleolus
7 Lateral malleolus
8 Calcaneal tuberosity
8.67 Posterior aspect of the lower leg and heel: muscle attachments
1 Semimembranosus
2 Popliteus
3 and 6 Soleus
4 Tibialis posterior
5 Flexor digitorum longus
7 Flexor hallucis longus
8 Peroneus brevis
9 Tendo calcaneus
8.68 Posterior aspect of the lower leg and heel: superficial muscles
1 Gastrocnemius
2 Soleus
3 Tendo calcaneus
4 Peroneus longus
8.69 Posterior aspect of the lower leg and heel: deep muscles
1 Capsule of knee joint
2 Medial collateral ligament
3 Lateral collateral ligament
4 Popliteus
5 Soleus – partly excised
6 Flexor digitorum longus
7 Tibialis posterior
8 Flexor hallucis longus
9 Peroneal muscles
8.70 Posterior aspect of lower leg and heel: superficial structures
1 Biceps
2 Semitendinosus overlying
3 Semimembranosus
4 Sartorius
5 Gracilis
6 Medial and lateral heads of gastrocnemius
7 Soleus
8.71 Posterior aspect of the leg when standing on the toes
Movements of the ankle and intertarsal joints (Figs 8.72-8.75)
The ankle joint is a hinge joint between the talus and the mortise, formed between the lower ends of the tibia and fibula. The shape of the bones and powerful interosseous and medial and lateral ligaments maintain the stability of the joint. It is least stable in the plantar flexed position. Dorsiflexion is produced by tibialis anterior and other muscles of the extensor compartment of the leg; plantar flexion is primarily by the gastrocnemius and soleus muscles.
8.72 Dorsiflexion of the foot
8.73 Plantarflexion of the foot
8.74 Inversion of the foot
8.75 Eversion of the foot
The subtalar (posterior talocalcaneal) and talocalcaneonavicular joints act as a single unit at which inversion and eversion take place. Inversion (turning the sole inwards) is produced by tibialis anterior and posterior, and limited by tension in the peroneus longus and brevis muscles, and the interosseous talocalcaneal ligament. The movement is increased in plantarflexion and by movement at the midtarsal (talonavicular and calcaneocuboid) joint. Eversion (turning the sole outwards) is produced by the peroneal muscles and limited by the tibialis anterior and posterior muscles, and the medial ligament of the ankle joint. The movement is increased in dorsiflexion and by movement at the midtarsal joint. These movements are described with the foot off the ground; the same movements with the foot on the ground adjust the foot and lower limb to uneven and sloping surfaces. Also, when the foot is weight-bearing, there are additional movements of supination and pronation of the distal tarsus and metatarsus (forefoot) relative to the talus and calcaneus (hindfoot).
Sole of the foot (Figs 8.76-8.83)
The skin over the weight-bearing areas of the heel and the ball of the foot is thick and firmly attached to the fascia and its thickened central plantar aponeurosis by fibrous septa. These septa loculate subcutaneous fat producing a cushioning effect over the underlying tissues. The posterior aspect of the calcaneus and the heads of the metatarsals are palpable through this cushion but the remaining bones are deep to the short muscles (Figs 8.80-8.83). A sesamoid bone, embedded in the short tendons, is present on each side of the head of the first metatarsal.
8.76 Sole of the foot
8.77 Sole of the foot: bones
1 Calcaneus
2 Talus
3 Navicular
4 Cuboid
5 Lateral cuneiform
6 Intermediate cuneiform
7 Medial cuneiform
8 Metatarsals
9 Phalanges
8.78 Sole of the foot: muscle attachments
1 Flexor digitorum accessorius
2 Tibialis posterior
3 Peroneus brevis
4 Tibialis anterior
5 Peroneus longus
6 Plantar interossei
7 Abductor hallucis
8 Flexor hallucis longus
8.79 Sole of the foot: plantar fascia
1 Plantar aponeurosis
2 Transverse bands
3 Digital bands
4 Superficial transverse metacarpal ligament
8.80 Sole of the foot: first muscle layer
1 Abductor digiti minimi
2 Flexor digitorum brevis
3 Abductor hallucis
8.81 Sole of the foot: second muscle layer
1 Flexor hallucis longus
2 Flexor digitorum longus
3 Flexor digitorum accessorius
4 Four lumbrical muscles
The dotted line indicates the position of the posterior tibial artery and the tibial nerve. On entering the foot they divide into medial and lateral plantar vessels and nerves
8.82 Sole of the foot: third muscle layer
1 Adductor hallucis
2 Flexor hallucis brevis
3 Flexor digiti minimi brevis
8.83 Sole of the foot: fourth muscle layer
1 Long plantar ligament
2 Plantar calcaneonavicular ligament
3 Peroneus brevis
4 Peroneus longus
5 Tibialis posterior
6 Plantar interossei
The pattern of the small muscles of the foot is similar to that of the hand, but there are no opponens muscles and the flexor accessorius has no upper limb counterpart. The latter muscle is attached to the calcaneus posteriorly and to the lateral aspect of the tendon of the flexor digitorum longus anteriorly. The medial planter nerve supplies abductor hallucis, flexor hallucis brevis, flexor digitorum brevis and the first lumbrical; the remaining muscles are supplied by the lateral plantar nerve (Fig. 8.81). The long flexor tendons pass through the sole to gain attachment to the distal phalanges, flexing the toes, assisted by small muscles which also can produce slight fanning of the toes. The tendon of tibialis posterior passes to the tuberosity of the navicular and gives slips to most other tarsal and metatarsal bones.
The small muscles act with the long flexor tendons to maintain the plantar arches. These provide resilience to the foot and distribute the body weight over the sole, while still allowing it to act as a semi-rigid lever propelling the body forwards. The arches can be divided into medial and lateral longitudinal, and transverse, but they act as a single unit. Each arch is maintained by bony, ligamentous and muscular factors.
The medial longitudinal arch is formed of the calcaneus, talus, navicular, three cuneiform and three medial metatarsal bones. The sustentaculum tali of the calcaneus gives support to the head of the talus and there is also some wedging of the bones along the length of the arch aiding its support. The plantar calcaneonavicular (spring) ligament supports the head of the talus and further contributions are from strong interosseous ligaments. The plantar aponeurosis ties the ends of the arch together, as do the long flexors of the hallux and adjacent two toes, with contributions from the short medial muscles of the sole. The tibialis anterior muscle provides powerful support from its attachments to the centre of the arch.
The lateral longitudinal arch is lower than the medial and is formed of the calcaneus, cuboid and fourth and fifth metatarsal bones; it is maintained mainly by ligaments, in particular the long and short plantars. The tendon of peroneus longus is beneath the centre of the arch and the long and short digital muscles provide some support. The transverse arch is maintained mainly by the wedge-shaped nature of the cuboid and cuneiform bones and their strong interosseous ligaments. The attachments of the peroneus longus and tibialis posterior provide some muscular support.
Innervation of the lower limb (Figs 8.84-8.87)
The lower limb is innervated by the sacral plexus. The groin gains additional sensory contributions from L1 and the perineal region from S3. Note that one kneels on L3 and L4, walks on S1 and sits on S3. The knee jerk is supplied by L3 and L4, the ankle jerk by S1 and the plantar reflex by S1 and S2. The L5 root is not represented in these reflexes but can be specifically tested in dorsiflexion of the great toe.
8.84 Cutaneous nerves and dermatomes of the lower limb: anterior
1 12th thoracic
2 Femoral branch of genitofemoral
3 Ilioinguinal
4 Lateral cutaneous nerve of thigh
5 Obturator
6 Intermediate femoral cutaneous
7 Medial cutaneous nerve of thigh
8 Saphenous
9 Lateral cutaneous nerve of leg
10,11 Superficial peroneal
12 Sural
13 Deep peroneal
L, Lumbar
S, Sacral
The numbers on the left limb, scrotum and perineum denote the nerve roots
8.85 Cutaneous nerves and dermatomes of the lower limb: posterior
1 Lumbar
2 Sacral
3 Iliohypogastric
4 12th thoracic
5 Lateral cutaneous nerve of thigh
6 Posterior cutaneous nerve of thigh
7 Obturator
8 Medial cutaneous nerve of thigh
9 Lateral cutaneous nerve of calf
10 Sural communicating
11 Sural
12 Saphenous
13 Tibial (medial calcaneal)
L, Lumbar
S, Sacral
The numbers on the right limb denote lumbar and sacral nerve roots. The bold right line indicates the dorsal and the left the ventral axial lines
8.86 Cutaneous innervation of the sole
1 Saphenous
2 Medial plantar
3 Lateral plantar
4 Sural
5 Tibial (medial calcaneal)
8.87 Cutaneous dermatomes of the sole: lumbar fourth and fifth and first sacral nerve roots
Injury to the femoral nerve produces loss of knee extension (quadriceps), some loss of hip flexion (iliacus and pectineus) and loss of sensation of the front and medial side of the thigh, leg and foot (anterior and medial femoral cutaneous, and the saphenous nerves). Damage to the obturator nerve denervates the adductor muscles but some adduction is retained because of the sciatic contribution to the adductor magnus; often there is no sensory loss.
The sciatic nerve may be injured in posterior dislocation of the hip joint: this produces an almost flail limb. A distal injury may spare the branches to the hamstrings and allow knee flexion. Injury to the tibial nerve produces loss of plantar flexion and sensory denervation of the sole of the foot.
Injury to the tibial nerve, near the ankle, denervates the small muscles of the sole; the unopposed action of the long flexor and extensor muscles produces a highly arched foot. Injury proximal to the origin of the sural nerve also produces loss of sensation of the lateral side of the leg and foot.
The common peroneal nerve is the most commonly injured nerve in the leg. This is often associated with fractures of the neck of the fibula or a badly fitting leg plaster. The power of dorsiflexion (extensor muscles) and eversion (peroneal muscles) is lost, and the foot drops and becomes inverted: there is sensory loss over the medial side of the dorsum of the foot. In superficial peroneal nerve injuries, the foot is inverted due to loss of eversion (peronei): sensory loss is over the medial part of the dorsum of the foot. In deep peroneal nerve injuries, the power of dorsiflexion of the foot and toes is lost and there may be loss of sensation between the first and second toes: the foot becomes inverted by the unopposed action of the tibialis posterior muscle.
Vessels of the lower limb (Figs 8.88-8.89)
8.88 Vessels of the lower limb: anterior
1 Femoral (common femoral) artery
2 Deep femoral (profunda femoris) artery
3 Femoral (superficial femoral) artery
4 Anterior tibial artery
5 Dorsalis pedis artery
6 Posterior tibial artery
7 Dorsal venous arch
8 Great saphenous vein
9 Saphenous opening (see also Fig. 8.8)
10 Vertical chain of inguinal lymph nodes
11 Horizontal chain of inguinal lymph nodes
12 Point of access to femoral artery
13 perforating peroneal artery
8.89 Vessels of the lower limb: posterior
1 Popliteal artery
2 Anterior tibial artery
3 Posterior tibial artery
4 Peroneal artery
5 Small saphenous vein