ANATOMY: Hip, Thigh and Knee Flashcards
Which bones make up the pelvic girdle?
- sacrum
- coccyx
- hip bone
Describe the hip bones
Made of three separate bones: ilium, pubis, ischium
Prior to puberty,thetriradiate cartilage separates these parts – and fusion only begins at the age of 25ish
Together, the ilium, pubis and ischium form theacetabulum. The head of the femur articulates with the acetabulum to form thehip joint
Label this, what does it show?
greater and lesser trochanters - muscular attachment point
What are the 2 big ligaments which are in the hip joint?
2 big ligaments: sacrotuberous ligament (runs sacrum to ischial tuberosity)
sacrospinous ligament (runs sacrum to ischial spine)
Placement of these ligaments form a hole at the sciatic notches:
- lesser sciatic foramen
- greater sciatic foramen
Label these ligaments and explain their function
These three ligaments wrap around the head of the femur
As you extend the leg (bring it backwards), it causes them to spiral which draws the hip in more
The more extended the hip joint is = the stronger it is
so when hip joint is flexed = it is at its weakest (e.g. sitting position)
The medial and lateral menisci are fibrocartilage structures in the knee that serve two functions. What are these functions?
To deepen the articular surface of the tibia, thus increasing stability of the joint.
To act as shock absorbers by increasing surface area to further dissipate forces.
Describe the patellar ligament
Patellar ligament – a continuation of the quadriceps femoris tendon distal to the patella. It attaches to the tibial tuberosity.
Describe the collateral ligaments
Collateral ligaments – stabilise the hinge motion of the knee, preventing excessive medial or lateral movement
Tibial (medial) collateral ligament – wide and flat, on the medial side of the joint. Proximally, it attaches to the medial epicondyle of the femur, distally it attaches to the medial condyle of the tibia.
Fibular (lateral) collateral ligament – thinner and rounder, attaches proximally to the lateral epicondyle of the femur, distally it attaches to a depression on the lateral surface of the fibular head.
Describe the cruicate ligaments
Cruciate Ligaments connect the femur and the tibia. In doing so, they cross each other
Anterior cruciate ligament: attaches at the anterior intercondylar region of the tibia. It ascends posteriorly to attach to the femur in the intercondylar fossa. It prevents anterior dislocation of the tibia onto the femur.
Posterior cruciate: attaches at the posterior intercondylar region of the tibia. Ascends anteriorly to attach to the anteromedial femoral condyle. It prevents posterior dislocation of the tibia onto the femur.
What does it suggest if the medial collateral ligament is damaged?
If the medial collateral ligament is damaged, it is more than likely the medial meniscus that is torn, due to their attachment.
What are the compartments of the leg?
Describe the anterior compartments of the leg
Describe the iliiopsoas muscle
The iliopsoas is comprised of psoas major and iliacus. Unlike many of the anterior thigh muscles, the iliopsoas does not perform extension of the leg at the knee joint.
Attachments: psoas major originates from the lumbar vertebrae, iliacus originates from the iliac fossa of the pelvis. They insert together onto the lesser trochanter of the femur and form a common tendon.
Actions: Flexion of the thigh at the hip joint.
Innervation: The psoas major is innervated by anterior rami of L1-3, while the iliacus is innervated by the femoral nerve.
Describe the sartorius muscle
The sartorius is long and thin, runs inferiomedially across the thigh. Positioned more superficially than the other muscles in the leg.
Originates from the anterior superior iliac spine, and attaches to the superior, medial surface of the tibia.
Actions: At the hip joint, it is a flexor, abductor and lateral rotator. At the knee joint, it is also a flexor.
Innervation: Femoral nerve.
Describe the pectineus mucsle
The pectineus is flat, quadrangular-shaped, contributes to the floor of the femoral triangle.
Originates from the pectineal line of the pubis bone. It inserts onto the pectineal line on the posterior femur, immediately inferior to the lesser trochanter.
Actions: Adduction and flexion at the hip joint.
Innervation: Femoral nerve. Maybe also a branch from the obturator nerve.
What is the quadriceps femoris?
The quadriceps femoris consists of four individual muscles – 3 vastus muscles and the rectus femoris. It forms the main bulk of the anterior thigh
The four muscles collectively insert onto the patella via the quadriceps tendon. The patella, in turn, is attached to the tibial tuberosity by the patella ligament.
Describe the 4 muscles of the quadriceps femoris
Vastus Lateralis: Originates from the greater trochanter and the lateral lip of linea aspera of the femur.
Vastus Intermedius: Originates from the anterior and lateral surfaces of the femoral shaft.
Vastus Medialis: Originates from the intertrochanteric line and medial lip of the linea aspera of the femur.
Note- all 3 muscles above have the action of extending the knee joint and also flexing the patella.
Rectus Femoris: Originates from anterior inferior iliac spine and the ilium of the pelvis. It attaches to the patella via quadriceps femoris tendon.
Extends knee joint AND flexes hip joint
Innervation for ALL of these: Femoral nerve.
Sartorius from ASIS to the medial side of the tibia.
Describe the muscles in the medial comaprtment of the thigh
Medial compartment of the thigh muscles are collectively known as the hip adductors.
5 muscles in this group; gracilis, obturator externus, adductor brevis, adductor longus and adductor magnus.
All the medial thigh muscles are innervated by the obturator nerve, which arises from the lumbar plexus. Arterial supply is through the obturator artery
Describe the adductor magnus
Largest muscle in the medial compartment of the thigh. Comprised of adductor and hamstring
Adductor: Originates from the inferior rami of the pubis and the rami of ischium, attaches to the linea aspera of the femur. Adducts and flexes the thigh
Hamstring: Originates from the ischial tuberosity, attaches to the adductor tubercle and medial supracondylar line of the femur. Adducts and extends the thigh
Adductor=Obturator nerve (L2-L4)
Hamstring=Tibial component of sciatic nerve (L4-S3).
Describe the adductor longus muscle
The adductor longus partially covers the adductor brevis and magnus. Forms the medial border of the femoral triangle.
Originates from the pubis bone, expands into a flat fan shape. It has a broad distal attachment along the linea aspera of the femur.
Adducts the thigh, innervated by obturator nerve (L2-L4).
Describe the adductor brevis muscle
The adductor brevis is a short muscle, lying underneath the adductor longus.
It separates the anterior and posterior branches of the obturator nerve and is an important anatomical landmark within the medial thigh.
Attachments: Originates from pubis and inferior pubic rami. Attaches to the linea aspera on the posterior femur (proximal to adductor longus).
Abducts the thigh, innervated by obturator nerve (L2-L4).
Describe the obturator externus and the gracilis muscle
The obturator externus originates from the obturator foramen and adjacent bone. It passes under the neck of femur and attaches onto the posterior aspect of the greater trochanter.
Actions: thigh adduction and lateral rotation
The gracilis is the most superficial and medial of the muscles. Crosses at both the hip and knee joints. Originates from the inferior rami + body of the pubis. It descends down the medial aspect of the thigh and attaches to the medial surface of the tibial shaft.
Actions: thigh adduction at the hip and leg flexion at the knee.
What is shown by the different shaded colours?
Femoral triangle ends in the adductor canal
Femoral artery runs through the adductor hiatus, then goes behind the knee (the popliteal fossa)
What are the contents and borders of the femoral triangle?
The gluteus maximus is one of the superficial muscles of the glutes. Describe this
The gluteus maximus is the largest + most superficial. Originates from the gluteal (posterior) surface of the ilium, sacrum and coccyx. The fibres insert onto the iliotibial tract and gluteal tuberosity of the femur.
Actions: main extensor of the thigh, assists w lateral rotation. Only used when force is needed, eg climbing
Innervation: Inferior gluteal nerve.
The gluteus medius is one of the superficial muscles of the glutes. Describe this
The gluteus medius: fan-shaped, lies between to the max + minimus.
Originates from the gluteal surface of the ilium and inserts into the lateral surface of the greater trochanter.
Gluteus minimus: deepest and smallest of the superficial gluteal muscles.
Originates from the ilium and converges to form a tendon, inserting to the anterior side of the greater trochanter.
Actions of both: Abduction and medial rotation of the lower limb. Stabilises the pelvis, prevents pelvis drop on the contralateral side.
Innervation: Superior gluteal nerve.
Tensor fascia lata is another superficial muscle of the glute. Describe this
Tensor Fascia Lata: lies towards the anterior edge of the iliac crest. Tighten the fascia lata, and so abducts and medially rotates the lower limb.
Originates from the anterior iliac crest, attaching to the anterior superior iliac spine (ASIS). It inserts into the iliotibial tract, which itself attaches to the lateral condyle of the tibia.
Innervation: Superior gluteal nerve.
Describe the deep muscles of the glutes
Piriformis: Originates from the anterior surface of the sacrum. The fibres travel inferiorly and laterally through the greater sciatic foramen to insert onto greater trochanter of the femur.
Innervation: Nerve to piriformis.
Obturator Internus: forms the lateral walls of the pelvic cavity.
Originates from the pubis and ischium at the obturator foramen. It travels through the lesser sciatic foramen, and attaches to the greater trochanter.
Innervation: Nerve to obturator internus
Actions of both: Lateral rotation and abduction.
What is a trendelenburg gait?
A trendelenburg gait results from a defective hip abductor mechanism.
The primary musculature involved is the gluteal musculature, including the gluteus medius and gluteus minimus muscles. The weakness of these muscles–> drooping of the pelvis to the contralateral side while walking
Describe the biceps femoris
Biceps Femoris: The long head originates from the ischial tuberosity. The short head originates from the linea aspera on posterior femur surface. Together, the heads form a tendon, which inserts into the head of the fibula.
Actions: Flexion at the knee. Also extends the thigh at the hip, and laterally rotates at the hip and knee.
Long head innervated by tibial part, short head innervated by common fibular part of the sciatic nerve.
Describe the semitendinosus muscle
Semitendinosus: originates from the ischial tuberosity, attaches to the medial surface of the tibia (pes anserinus).
Semimembranosus muscle: deep to the semitendinosus on the medial aspect of the posterior thigh. Originates from the ischial tuberosity (more superiorly than the semitendinosus and biceps femoris). Attaches to the medial tibial condyle.
BOTH Flex the leg at the knee joint. Extends thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint.
Innervation: Tibial part of the sciatic nerve.
