Lower Limb

1. MUSCLES OF THIGH
&
GLUTEAL REGION
Dr M Idris Siddiqui

2. The hip & buttock
• This transitional region between the trunk and
free lower limb includes two parts of the
lower limb:
1. The rounded, prominent posterior region,
the buttocks (L. nates, clunes).
2. The lateral, usually less prominent hip
(L. coxa) or hip region (L. regio coxae),
which overlies the hip joint and greater
trochanter of the femur.

3. Gluteal region (L. regio glutealis)
• The gluteal region is bounded:
–Superiorly by the iliac crest,
–Medially by the intergluteal (natal) cleft
(L. natus, to be born), and
–Inferiorly by the skin fold (groove)
underlying the buttock, the gluteal fold
(L. sulcus glutealis).
• The gluteal muscles constitute the bulk of
this region.

4. Thigh or femoral region
(L. regio femoris)
• This part/region of the free lower
limb lies between the gluteal,
abdominal, and perineal regions
proximally and the knee region
distally.
•It contains most of the femur (thigh
bone), which connects the hip and knee.

6. The inguinal region or groin.
–The transition between the trunk and free
lower limb is abrupt anteriorly and medially.
The inguinal region of the body, also
known as the groin, is located on the
lower portion of the anterior abdominal
wall, with the thigh inferiorly, the pubic
tubercle medially, and the anterior
superior iliac spine (ASIS) superolaterally.

7. The muscles of the thigh
• The fascia lata , It is a deep fascial investment of the
whole thigh musculature.
• The musculature of the thigh can be split into these
sections:
– Anterior ,
– Medial ,
– Posterior .
• Each compartment has a distinct innervation and function.
– Lateral.
• Iliotibial tract, a modification of the fascia lata
• Tensor Fasciae Latae: connects to the iliotibial tract

9. Muscles in the Anterior Compartment
of the Thigh
• There are three major muscles in the
anterior thigh:
–Pectineus (some anatomists consider it in medial compartment) ,
–Sartorius,
–Quadriceps femoris.
• In addition to these, the end of
the iliopsoas muscle passes into the anterior
compartment.

12. MUSCLES IN THE MEDIAL
COMPARTMENT OF THE THIGH
• The muscles in the medial compartment of the
thigh are collectively known as the hip adductors.
• There are five 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 via the obturator artery.

13. The muscles of the medial compartment of the thigh are ordered into 3 layers.

15. MUSCLES IN THE POSTERIOR
COMPARTMENT OF THE THIGH
• The muscles in the posterior compartment of the
thigh are collectively known as the hamstrings.
– They consist of :
• Biceps femoris,
• Semitendinosus and
• Semimembranosus ,
– which form prominent tendons medially and laterally at the back of the
knee.
• As group, these muscles act to extend at the hip,
and flex at the knee.
– They are innervated by the sciatic nerve (L4-S3).

17. Adductor Hiatus
• The adductor hiatus is an opening or gap between
the aponeurotic distal attachment of the adductor
part of the adductor magnus and the tendinous
distal attachment of the hamstring part.
• The opening is located just lateral and superior to
the adductor tubercle of the femur.
• The adductor hiatus transmits:
– The femoral artery and vein from the adductor canal in
the thigh to the popliteal fossa posterior to the knee.

18. The muscles of the thigh
A. Anterior Compartment
* those that flex the hip (coxal) joint/thigh:
1. Iliacus:
2. Psoas Major:
3. Sartorius: also flexes knee joint/leg
* those that extend the knee joint/leg:
4. Quadriceps Femoris:
a. Rectus Femoris
b. Vastus Medialis
c. Vastus Intermedius
d. Vastus Lateralis
B. Medial Compartment - adduct the thigh
and flex hip joint/thigh
1. Adductors (Longus, Brevis, Magnus)
2. Pectineus
3. Gracilis: also flexes knee joint/LEG
C. Lateral Compartment - abducts thigh
1. Tensor Fasciae Latae: connects to the I
liotibial tract (iliotibial band, fascia
lata)
D. Posterior Compartment
* Gluteal muscles
1. Gluteus Maximus: extends hip
joint/thigh
2. Gluteus Medius: abducts thigh
3. Gluteus Minimus: abducts thigh
* "Hamstring" muscles: all extend the
hip joint/thigh and flex the knee
joint/leg
4. Biceps Femoris
5. Semitendinosus
6. Semimembranosus

21. MUSCLES OF THE GLUTEAL REGION
• The muscles of the gluteal region can be broadly divided into
two groups:
• Superficial abductors and extenders – A group of large
muscles that abduct and extend the femur.
– Gluteus maximus,
– Gluteus medius,
– Gluteus minimus
– Tensor fascia lata.
• Deep lateral rotators – A group of smaller muscles that
mainly act to laterally rotate the femur.
– Quadratus femoris,
– Piriformis ,
– Gemellus superior,
– Gemellus inferior
– Obturator internus.

23. Sciatic Foramina and Structures
Passing Through Them

25. Structures Under Gluteus Maximus
• Muscles
– Gluteus medius
– Gluteus minimus
– Reflected head of the rectus femori
– Piriformis
– Obturator internus with two gemelli
– Quadratus femoris
– Obturator externus
– Origin of the four hamstrings from the ischial
tuberosity
– Insertion of the upper or pubic fibres of the
adductor magnus.
• Vessels
– Superior gluteal vessels
– Inferior gluteal vessels
– Internal pudendal vessels
– Ascending branch of the medial circumflex
femoral artery
– Trochanteric anastomosis
– Cruciate anastomosis
– First perforating artery
• Bones and joints:
– Ilium
– Ischium with ischial tuberosity
– Upper end of femur with the greater trochanter
– Sacrum and coccyx
– Hip joint
– Sacroiliac joint.
• Nerves
– Superior gluteal nerve
– Inferior gluteal nerve
– Sciatic Nerve
– Posterior cutaneous nerve of the thigh
– Nerve to the quadrates femoris
– Pudendal nerve
– Nerve to the obturator internus
– The perforating cutaneous nerves
• Ligaments
– Sacrotuberous
– Sacrospinous
• Bursae
– Trochanteric bursa
– Ischial Bursa

26. Structures Lying Deep to the Gluteus
minimus
•Reflected head of the
rectus femoris
•Capsule of the hip joint.

27. 6 Lateral rotators the hip joint

28. Greater Sciatic Foramen
• The piriformis emerging from the pelvis fills the
foramen almost completely.
• Structures passing above the piriformis:
– Superior gluteal nerve
– Superior gluteal vessels
• Structures passing below the piriformis:
– Inferior gluteal nerve
– Inferior gluteal vessels
– Sciatic nerve
– Posterior cutaneous nerve of thigh
– Nerve to quadratus femoris
– Pudendal nerve
– Internal pudendal vessels
– Nerve to obturator internus.

30. Lesser Sciatic Foramen
• The upper and lower parts of the foramen are
filled up by origins of the two gemelli muscles.
• Tendon of obturator internus
• Pudendal nerve
• Internal pudendal vessels
• Nerve to obturator internus.

31. Anastmosis in Gluteal Region
• Trochanteric Anastomosis
– Trochanteric anastomosis is present near the
trochanteric fossa. It supplies branches to the head of
the femur.
– It is formed by
• Inferior division of the deep branch of the superior gluteal
artery
• Ascending branch of the medial circumflex artery
• Ascending branch of the lateral circumflex artery
• Inferior gluteal artery.
• This anastomosis is a channel of communication
between the internal iliac and femoral arteries.

32. Anastmosis in Gluteal Region
Cruciate Anastomosis
This anastomosis is situated over the upper part of the
back of the femur at the level of the middle of the
lesser trochanter.
It is formed by:
– Anastomotic branch of the inferior gluteal artery
– Ascending branch of the first perforating artery
– Transverse branch of the medial circumflex femoral artery
– Transverse branch of the lateral circumflex femoral artery.
This anastomosis is a connection between the internal
iliac and femoral arteries.

33. Clinical Significance of Gluteal Region
Intramuscular Injections
Intramuscular injections are given in the anterosuperior quadrant of the
gluteal region, ie., in the glutei medius and minimus.

35. Clinical Relevance
Damage to the Hamstrings
• Muscle Strain
• A hamstring strain refers to excessive stretch or tearing of the
muscle fibres. They are often seen athletes involved in running or
kicking sports. Damage to the muscle fibres is likely to rupture the
surrounding blood vessels – producing a haematoma (a collection
of blood). The haematoma is contained by the overlying fascia
lata.
• Treatment of any muscle strain should utilise the RICE protocol –
rest, ice, compression and elevation.
• Avulsion Fracture of the Ischial Tuberosity
• An avulsion fracture occurs when a fragment of bone breaks away
from the main body of bone.
• In an avulsion fracture of the ischial tuberosity, the hamstring
tendons ‘tear off’ a piece of the ischial tuberosity. Such an injury
usually occurs in sports that require rapid contraction and
relaxation of the muscles – such as sprinting, football and hurdling.

36. Weakness of Gluteus medius and minimus
• These muscles are principal hip abductors and
important in stabilizing pelvis when a person walks.
• If weak, the affected person has to sway on the
paralysed side to clear the opposite foot of the ground
to compensate for lack of function. The person walks
with lurching gait. Bilateral affection leads to waddling
gait.
• Normally when the body weight is supported on one
limb, the glutei of supported side raise the opposite
(and unsupported) side of the pelvis. However, if the
abductor mechanism is defective, the unsupported side
of the pelvis drops [Positive Trendelenburg’s test]. The
extra sway towards the affected side is used to
compensate the drop and improve foot clearance.

37. Weakness of Gluteus Maximus
• Paralysis of gluteal muscle weakens
the extension of the hip. The patient is not
able to stand up from a sitting posture
without support. Such patients, while trying
to stand up, rise gradually, supporting their
hands first on the legs and then on the thighs.
This climbing on oneself is a frequently seen
feature in muscular dystrophies.

40. Key Points
• Nelaton’s line: It’s the line joining the anterior
superior iliac spine and the most notable point of
ischial tuberosity. It crosses the tip of greater
trochanter.
• Bryant’s triangle: With the patient in supine
position, first draw a vertical line passing
downwards from the anterior superior iliac spine
(ASIS) and now draw a line going from ASIS to the
tip of greater trochanter (spinotrochanteric line).
Lastly draw a horizontal line from the tip of greater
trochanter to the very first line. The triangle so
created is referred to as Bryant’s triangle.

42. The dimples of Venus (also known as back dimples), are
sagittally symmetrical indentations sometimes visible on the
human lower back, just superior to the gluteal cleft.

43. Clinical Relevance
Damage to the Superior Gluteal Nerve
Positive Trendelenburg sign, characteristic of left superior
gluteal nerve palsy.
• The superior gluteal nerve innervates the gluteus
medius and the gluteus minimus. These muscles have
an important role in stabilising the pelvis during
locomotion. In the standing position, the gluteus
minimus and medius contract when the contralateral
leg is raised, preventing the pelvis from dropping on
that side.
• If the superior gluteal nerve is damaged, the previously
described muscles are paralysed – and the pelvis
becomes unsteady. A characteristic finding of gluteal
muscle weakness is the Trendelenburg sign.

45. Trendelenburg Sign
• The Trendelenburg sign is produced when
the patient is asked to stand unassisted on each leg
in turn. In a positive sign, pelvic drop will occur on
the unsupported leg. Pelvic drop can be recognised
by observing the level of the iliac crests on both
sides.
• For example, if the left gluteal muscles are weak,
the right side of the pelvis will drop when the
patient stands on their left leg (and the right leg is
unsupported).

46. Clinical Relevance
Testing the Quadriceps Femoris
• The quadriceps femoris muscle can be used to
test the femoral nerve in cases of suspected
nerve palsy.
• This is performed by positioning the patient
supine, with the knee slightly flexed. The
patient is asked to extend the leg (at the knee)
against resistance. If the femoral nerve is
damaged, contraction of the quadriceps
femoris will be absent.

47. Clinical Relevance
Injury to the Adductor Muscles
• Strain of the adductor muscles is the underlying
cause of what is colloquially known as a ‘groin
strain‘. The proximal part of the muscle is most
commonly affected, tearing near their bony
attachments in the pelvis.
• Groin injuries usually occur in sports that require
explosive movements or extreme
stretching. Treatment of any muscle strain should
utilise the RICE protocol – rest, ice, compression
and elevation.

48. Clinical Relevance
Landmark of the Gluteal Region
• The piriformis is an important anatomical landmark in the
gluteal region.
• As the muscle travels through the greater sciatic foramen, it
effectively divides the gluteal region into an inferior and
superior part. This division determines the name of the
vessels and nerves that supply the area. The superior
gluteal nerve and vessels emerge into the gluteal region
superiorly to the piriformis (and vice versa for the inferior
gluteal nerve).
• In addition, the piriformis can be used to locate the sciatic
nerve (a major peripheral nerve of the lower limb). The
sciatic nerve enters the gluteal region directly inferior to the
piriformis, and is visible as a flat band, approximately 2cm
wide.

49. SCIATIC NERVE BLOCK
PIRIFORMIS SYNDROME
• SCIATIC NERVE BLOCK
• The sciatic nerve is blocked by injecting an anesthetic agent
several centimetres below the midpoint of the line joining
the PSIS and the upper border of the higher trochanter.
• PIRIFORMIS SYNDROME
• It’s a clinical conditioncharacterized by pain in buttock
because of compression of the sciatic nerve by the
piriformis. It normally takes place in sports that need
excessive usage of gluteal muscles (example, ice skaters,
cyclists, etc.), causing hypertrophy or spasm of piriformis

50. CLINICAL SIGNIFICANCE
CLINICAL IMPORTANCE OF HAMSTRING MUSCLES
• If hamstring muscles are paralyzed, the patient
tends to drop forwards as the gluteus maximus
muscle can not keep the essential tone to stand
erect.
• In ancient times, the soldiers utilized to slash the
rear of the knees of horses of their rivals to be able
to cut the tendons of hamstring muscles, to bring
the horse and its rider down. They also utilized to
cut the hamstring tendons of soldiers in order that
they couldn’t run. This was referred to as
“hamstringing” the enemy.