Leg Anatomy

The lower limbs are made up of a set of 4 bones and a variety of muscles and ligaments that allow biomechanical movements without great effort. The legs are responsible for supporting the entire body weight and articulating the hip, knee and feet. As a result, leg injuries are frequent due to the work they do.

❮

Microwaveable Heating Pads

Ice Gel Packs

Compression Sleeves

Acupressure

Electric Massagers

TENS & EMS Units

❯

Parts and anatomy of the leg

Bones and joints

• Femur: It is the longest and strongest bone in the human anatomy. It forms part of the coxofemoral joint, inserting itself into the acetabulum cavity by means of the femoral head and the knee joint by means of the trochlea of the tibia.
• Patella: lies in front of the femur and articulates with this bone by means of the terminal tendon, related to the quadriceps femoris.
• Fibula: This elongated bone has three sides and runs along the outside of the leg. The styloid process forms part of the knee joint, while the lateral malleolus forms part of the talus of the ankle.
• Tibia: Another elongated S-shaped bone. It is integrated into the knee joint through the proximal epiphysis, while the distal epiphysis is part of the ankle joint.
• Knee: This joint joins the femoral condyles with the patella and the upper part of the tibia. It is possible to find the intercondylar fossa, the cruciate ligaments, the menisci and the transverse ligament.
• Tibioperonea superior: This articular body moves the lateral tuberosity of the tibia with the fibula, joined by ligaments.
• Intermediate tibioperoneal: The fibula is connected to the tibia by a membrane.
• Inferior tibioperoneal: This joint takes the lower part of the tibia and fibula.
• Tibioperoneoastotalar: The talus, malleoli and tibia join at this joint to give movement to the ankle. It can also be considered part of the foot.

Muscles

• Sartorius: The longest muscle in the body, originating from the anterior superior iliac spine and ending on the upper surface of the tibia. Its action is to flex the hip and knee, taking into account the position of the femur.
• Vastus lateralis: It is part of the muscles called quadriceps femoris together with vastus medialis, cruralis and rectus femoris. It arises from the fibrous membrane of the greater trochanter of the femur to the quadriceps tendons. Its action is to stabilise the knee in extension.
• Rectus femoris: It runs from the iliac spine to the quadriceps tendon to allow coordinated knee extension and hip flexion.
• Vastus medialis: Its pathway is from the intertrochanteric line of the femur to the patellar tendon. This allows extension of the knee.
• Crural: From the lateral anterior part of the femur to the patellar ligament, this muscle can be seen. It is an extensor of the leg.
• Peroneus longus: The external tuberosity of the fibula gives rise to this muscle which inserts on the cuneiform plantar aspect and on the first metatarsal.
• Peroneus brevis: Located on the lateral side of the fibula, it arises below the knee and inserts on the external aspect of the fibula and on the fifth metatarsal. Rotation and abduction of the foot are generated by this muscle.
• Peroneus anterior: It arises from the fibula and inserts on the fifth metatarsal. Its function is to allow eversion of the foot and dorsal flexion.
• Tibialis anterior: located in the lower part of the leg, on the anterior side. Its course begins at the interosseous membrane and on the surface of the tibia to the medial underside of the medial cuneiform and the first metatarsal bone. Inversion and flexion of the foot is the action generated by this muscle.
• Posterior tibialis: Its elongated shape allows it to run from the tibia and fibula to the medial cuneiform and to the second, third and fourth metatarsal bones. Flexion, plantar adduction and foot stability are tasks of this muscle.
• Popliteus: Responsible for flexion of the leg at the knee. It arises from the condyle of the femur and inserts into the upper tibia.
• Semimembranosus: Belongs to the hamstring group, together with biceps femoris and semitendinosus. It arises from the ischium and inserts on the medial condyle of the tibia bone. Its action allows extension of the hip and flexion of the knee.
• Semitendinosus: Its course begins at the tuberosity of the ischium and ends at the medial surface of the tibia, at its upper end. As it passes through the hip and knee, it allows the leg to flex and keep the hip extended.
• Biceps femoris: It runs from the ischial tuberosity to the fibula. It allows rotation and flexion of the knee and extension of the hip.
• Adductor: It arises from the ischium and inserts into the femur. It can be divided into three sections; major, medial and minor. Its function is related to the movement of the thigh.
• Inner gastrocnemius: Also known as the calf muscle, the condyles of the femur give rise to this muscle until it reaches the calcaneus of the foot.
• External gemellus: It has the same route as the previous muscle, but its action is to plantar flex the foot.
• Soleus: Together with the gastrocnemius, they form the so-called triceps suralis muscle. It is found at the back of the leg, as it arises from the fibula and tibia and fits into the calcaneus.
• Flexor hallucis longus: These muscles start at the tibia and insert into each of the phalanges of the toes to achieve flexion.
• Flexor hallucis longus: The origin of this muscle is the last part of the fibula and inserts into the posterior phalanx of the big toe. Its task is to allow flexion of this toe.
• Plantar: The external supracondylar crest of the femur, which inserts on the Achilles tendon (on the inside). Plantar flexion of the foot and knee are the actions performed by this muscle.
• Extensor longus: Pure work to allow dorsiflexion of the foot dorsally and extension of the big toe. It arises from the medial area of the fibula and inserts into the distal phalanx of the big toe.
• Extensor digitorum: The action of this muscle is to produce extension of the toes, except for the big toe. The tibia and fibula are the bones from which it originates.
• Gracilis muscle: Also known as rectus internus. It originates in the ischium and ends in the tibia. Its action controls the movements of the hip.

Ligaments

• Lateral collateral: It is located on the outer side of the knee joint and connects the femur to the fibula bone.
• Medial collateral: This ligament runs along the inside of the knee, connecting the fibula to the femur.
• Patellar: It is located in the knee and is known to be the continuation of the quadriceps femoris muscle group. It runs under the patella, inserting into the patella and the tibia.
• Anterior cruciate: The job of this ligament is to prevent the tibia from moving forward, so it joins the femur on its upper lateral part with the medial section of the tibia, on its anterior side. It passes under the patella.
• Posterior cruciate ligament: Unlike the anterior ligament, this tissue prevents the tibia from moving backwards with respect to the femur. It is often torn during strenuous activity.
• Transverse: Also known as the jugal ligament due to its action of joining the menisci on their anterior sides.
• Meniscofemoral: It is possible to find this ligament under the name of Humphrey. It is responsible for joining the femoral condyle (on its inner side) to the external meniscus.
• Posterior meniscofemoral or Wrisberg's ligament: In this case, this tendinous tissue joins the internal condyle of the femur bone with the meniscofemoral ligament.
• Popliteus obliquus: This is a ligament that runs from the external condyle of the femur to the semimembranosus.
• Popliteus arcuate: The origin of this ligament is the same as that of the oblique ligament, but it inserts on the head of the fibula.
• Alar patellar: It runs from the inner aspect of the femur to the patella.
• External patellar alar: The external condyle of the femur is attached by this ligament to the edge of the patella.
• Internal patellar meniscus: The internal meniscus is attached to the patella by this ligament.
• Internal lateral: Also known as the tibial collateral. Its function is to attach the femur to the tibia.
• External patellar meniscus: The function of this ligament is to attach the external meniscus to the patella.
• Patellofemoral: It is responsible for keeping the lateral displacement of the patella balanced. It develops in the middle part of the femur (from a distal view) to the patella.
• Iliofemoral: This ligament belongs to the hip joint, but attaches at the femur so it can also be considered a ligament of the leg. It is also known as Bigelow's ligament.
• Ischifemoral: As in the previous case, this tissue belongs to the hip, joining the ischium with the femur, so it is possible to place it within the group of ligaments of the legs.
• Femoral head or round: The femoral head joins the diaphysis of the pelvis by means of this ligament to form the hip joint.

Biomechanics of the leg

• Flexion: Consists of lifting the knee to the trunk and keeping the knee extended or flexed. The maximum opening angle of this movement is around 110 to 130°. This is produced by the displacement of the condyles of the tibia and the menisci, maintaining the limit established by the posterior cruciate ligament.
• Extension: This is a movement that is performed when the leg is brought backwards. The opening does not exceed 30°.
• Abduction: Taking the external part of the pelvis as the axis, it is possible to move the leg in front of the other leg in the direction of the other leg by up to 30°. In other words, it is a matter of placing one knee in front of the other, keeping one foot on the floor.
• Adduction: This is the opposite movement to abduction, as in this case the leg is placed on the outside of the trunk and lifted up to 180° with a lot of training. In this movement, the foot remains next to the head.
• Internal rotation: This consists of placing the foot backwards and bending the knee by turning it towards the inside of the body. This opening does not exceed 40°. The sartorius, semitendinosus, semimembranosus, biceps femoris and rectus femoris are the muscles that produce this movement.
• External rotation: By placing the foot backwards and extending the knee to the outer side of the trunk, the biomechanical movement that bears this name is performed. The opening limit is 45°.