9.01 Bones and Muscles of the Hip/Thigh Flashcards
Describe the shape of the hip bone and its three major parts
The hip bone is made up of:
- Pubis
- Isheal bone
- Ilium
Label the following parts of the hip bone
There are three lines on the lateral aspect of the Ilium of the hip bone.
What are they called and what is their function?
They are the posterior, anterior and inferior gluteal lines
Between these lines are the attachment sites for the gluteal muscles
What is the intertrochanteric line on the femur bone?
It is a line on the anterior aspect of the proximal femur
It runs from the greater trochanter to the lesser trochanter that continues to wrap around posteriorly
Describe the distal aspect of the femoral bone
It flares out to form a lateral and a medial condyl for attachment for the knee joint. It also forms the patellar surface (a groove on the anterior part of the femur) for sliding up and down of the patellar bone in flexion and extension
What is the major muscle that arises from the anterior shaft of the femur bone?
Vastis Intermedius arises from muscle fibres (and not tendinous fibres) which is why the shaft of the bone is smooth with no elevations or landmarks.
The intertrochanteric line continues around posteriorly. Describe its course on the posterior aspect
It wraps around the bone laterally onto the posterior aspect to a little ridge called the spiral line which is continuous with the medial margin of the bone to the linea aspera (“rough bone”) that runs along the length of the posterior aspect of the bone
Describe the two lips of the linea aspera
The medial lip which becomes a medial suprachondylar line terminating as the adductor tubercle on the medial side
The lateral lip comes from the greater trochanter on the posteior side forming the gluteal tubercle which then forms the lateral lip down to the lateral suprachondylar ridge and lateral tubercle
Which part of the femur has more muscle attachments? The anterior or the posterior?
The posterior aspect has numerous muscle attachments
Describe the arrangement of the attachments of the gluteal muscles on the posterio-lateral aspect of the hip bone
- Medial most is the gluteus maximus muscle which is a powerful extensor of the hip
- The gluteus medius sits in the middle part of the hip bone
- The gluteus minimus is the lateral most muscle from the ililum of the hip bone
They are all separated by the gluteal lines
Describe the fascia of the thigh
The thigh is surrounded by deep fascia called the fascia lata. It spans from the hip down to blend with the fascia of the lower leg.
It has intramuscular septa that divide the thigh into 3 compartements
The fascia lata has a lateral thickening, what is the importance of it?
that forms the iliotibial band (ITB): it projects from the pelvis to the lateral aspects of the knee
The deep fascia has penetrations into the thigh in an unequal manner forming three compartments of the thigh.
What are these compartments?
- Anterior (The most extensive) which contains the hip flexors and knee extensors - the QUADRICEPTS
- Posterior which contains the hip Extensors and Knee Flexors - the HAMSTRINGS
- Medial which contains the hip adductors
(The gluteal compartement is only in the hip area above the gluteal tuberosity containing the abductors)
Describe the nerve supply to the different compartments of the thigh (include the gluteal compartment in this)
- Anterior: femoral nerve
- Posterior: sciatic nerve
- Medial: obturator nerve
- gluteal: gluteal nerve
The anterior compartment is the most comprehensive, what are the major structures running through it?
- The femoral bone itself
- The femoral artery
- The muscles (hip flexors and knee extensors)
- The Ileotibial band
Some muscles demarcate certain regions in the thigh. Name the labelled regions
- Femoral triangle
- Subsartorial canal
- Anterior compartment of thigh
- Medial compartment of thigh
- Gluteal region
- Posterior compartment of thigh
- Popliteal fossa
Describe the borders of the femoral triangle
Sartorius muscle at the pelvis to the medial part of the knee forms the lateral border
The adductor longus muscle line demarcates this (with the inguinal ligament
What is the popliteal fossa (the back of the knee) demarcated by?
The hamstrings above and heads of gastroneumeus below
What is the most powerful hip flexor? What is the origination?
Iliopsoas muscle (made up of psoas major + iliacus)
- The Iliacus muscle comes from iliac fossa on anterior part of hip bone
- Psoas major arises from verebral bodies of T12 -L5
- Psoas major sits just above psoas with a long slender body and is vestigial
Together they insert with a common tendinous insertion into the lesser trochanter of the femur
What is the bursae between the ilieopsoas insertion and the hip joint capsule?
The head of the femur is anteverted (outside the acetabulum) but is protected by a non-communicating bursae that lies between insertion of iliopsoas and capsule of hip joint.
It is susceptible to irritation in repetitive flexion activities especially against resistance.
What surrounds the iliopsoas muscle? How is this important for pathology?
Covered by fascia (psoas & iliacus) - Can provide passageway for abscesses
What is significant about the origins of the psoas major muscle?
Because it is a segmental muscle origin, there are tendinous arches that form across the verebral bodies (spaces between fasciulae)
Through the openings: nerves of lumbar plexuses originate, which pass laterally and form a plexus within the substance of psoas major
Branches of lumbar plexus appear either lateral to the muscle, medial to it or through it
Describe the sartorius muscle
It is the longest muscle of the body running deeply, from the ASIS travelling medially, inserting to medial aspect of tibia (into pes ansoremus: “gooses foot”)
Describe the pectineus muscle
A deep, short muscle that runs from the anterior pubis and inserts into the pectineal line of the medial femur
It sits at the division between the anterior compartment and medial compartment of the thigh
(thus often has a dual nerve supply - femoral and may also be supplied by obturator nerve)
What are the four muscles of the quadriceps?
Describe the origins of each one
- rectus femoris - from the anterior inferior ileac spine of the hip
- vastus medialis - from the posterior part of the femur from the medial lip of the linea aspera
- vastus lateralis - from the posterior part of the femur from the lateral lip of the linea aspera
- vastus intermedius - from the anterior shaft of the femur
The vastus medialis & lateralis attach posteriorly to linea aspera and insert into the knee at the tibia via the retinacula
What is the significance of the medialis’ orientation fo the knee?
Attachment via the retinaculum of the vastus medialis can pull the patella in medial direction counteracting and resisting the natural tendency for patella to be subluxed
(there are fibres called vastus medialus oblique that do this)
What is the articularis genu?
Tiny muscle deep to rectus femoris used when you genuflex - it is likely to pull the suprapatellar bursae out of the way when moving to knee extension
Describe the gracilis muscle
Arises from the pubic bone and is a long slender muscle running down and forms part of pes ancerinus attachments to medial aspect of tibia
Describe the arragement of the adductor longus, brevis and magnus muscles
They are arranged in three layers
- Adductor Longus: is the most anterior
- Adductor Brevis is intermediate
- Adductor magnus most posterior
What is special about the adductor magnus muscle?
It has extensive origin from two places on the hip bone from pubis and ischium. They projects towards the medial aspect of posterior tibia creating a gap (adductor hiatus)
This gap allows for vessels to pass from the medial thigh to posterior aspect of thigh to popliteal fossa
The adductor magnus muscle has 2 major parts to it. What are they?
Has some fibres that act as a power adductor of the thigh but there are also fibres projecting all the way down the adductor tubercle of the femur (tendinous attachment) - vestigial insertion (doesn’t cross the knee joint).
Describe the obturator extenus muscle
A very small muscle spanning between the pelvis and proximal part of the femur
What is the trandellenberg sign?
Found in people with weak or paralyzed abductor muscles: gluteus medius and gluteus minimus.
The gluteus medius is very important during the stance phase of the gait cycle to maintain both hips at the same level.
It is when the lack of this postural control of the pelvis causes the pelvis to the unsupported sign in walking
What is the tensor fascia lata?
An extensor muscle at knee – it also maintains tension in ITB & relieves femur of some weight bearing forces
It runs from the anterior part of the ilieac crest and inserts into a fascial band (Ileotibial Band) which goes down to the tibia.
It is susceptible to injury for running activities esp. downhill running as tendon snaps backwards and forwards across the boney attachment leading to inflammation
Where to the gluteal muscles attach onto?
Gluteus maximus goes to the gluteal tuberosity of the back of the femur, however the majority inserts into the ITB
Maximus and medius attach to the greater trochanter: good ability to abduct and resist falling away of pelvis
What are the function of the lateral rotators in the medial compartment of the thigh?
These are muscles that run deep to medius and minimus. They are short muscles running in line w/ the neck of the femur: act like a rotator cuff stabilising head of femur in the socket
- Piriformis
- Obturator internus
- Along with four others
What muscles make up the hamstrings? [3]
- Biceps femoris (inferomedial attachment to ischium) – 2 heads
- Semitendinosus (inferomedial attachment to ischium) – long tendon more superficially placed
- Semimembranosus (posterolateral attachment to ischium) – deep to semitendinosis
