STRUCTURES UNDER THE COVER OF GLUTEUS MAXIMUS

2. Thoracolumbar fascia
Gluteal apponeurosis
Gluteus maximus
Iliotibial tract
Sacrum
Coccyx
Hamstrings
GLUTEUS MAXIMUS-ORIGIN-

3. Superficial fibres
Deep fibres
Iliotibial tract
Gluteus medius
Gluteal apponeurosis
Gluteal
tuberosity
GLUTEUS MAXIMUS-INSERTION

4. • NERVE SUPPLY-
• By the inferior gluteal nerve (L5, S1, S2).
• Since finer twigs of the nerve reach the superficial part
of the muscle, the gluteus maximus and medius are
usually selected for intramuscular injections.
• BLOOD SUPPLY-
• By the superior and inferior gluteal arteries.

5. • ACTIONS-
• It is the powerful extensor of the hip joint .
• It comes into the action at the time of running,
fast walking and climbing the stair-case.
• But in standing and quiet walking it remains
inactive and the hamstrings alone act as hip
extensor.
• It as the chief anti-gravity muscle of the hip
joint.
• It is a strong lateral rotator of hip joint.
• Through the ilio-tibial tract it maintains the
extended position of knee joint.
• Upper fibres of act as powerful abductor of hip
joint.

7. Iliac crest
Tensor fascia latae
Gluteus minimus
Superior gluteal vessels and nerve
Gluteus medius
Pyriformis
Nerve to quadratus femoris
Tricipital tendon
Quadartus femoris
Sciatic nerve
Adductor magnus
Posterior cut.nerve of thigh
Ischial
tuberosity
Hamstrings
GM
Pudendal n
& vessels
Inf gl v & n
N to obt.int

8. • BONES AND JOINTS-
• Ilium;
• Ischium with ischial
tuberosity;
• Upper end of femur with
greater trochanter;
• Sacrum and coccyx
• Hip joint;
• Sacro-iliac joint.

9. • LIGAMENTS-
• Sacrotuberous;
• Sacrospinous
• and ischiofemoral.
• BURSAE-
• Trochanteric bursa
under gluteus maximus;
• bursae over ischial
tuberosity.

10. APPLIED ANATOMY
• Intramuscular
injections are given in
the anterosuperior
quadrant of the gluteal
region.
• i.e. in the glutei medius
and minimus, and
superficial part of
maximus.
• This is to avoid injury
to the large vessels and
nerves mainly sciatic
nerve.

11. • When Gluteus maximus is paralysed as in
muscular dystrophy-
• The patient cannot stand up from sitting
position without support.
• Such patients, while trying to stand up rise
gradually, supporting their hands first on the
legs and then on the thighs; they climb on
themselves.

12. • Our normal gait depends on –
• Gluteus medius and minimus
along.
• The fulcrum formed by the
relation of head of femur with
acetabulum .
• The weight transmitted
through the head and neck of
femur.
• Normally when the body
weight is supported on one
limb, the glutei of the
supported side raise the
opposite and unsupported side
of the pelvis.
• Thus it prevents the drooping
of pelvis on unsupported side.

13. • When gluteus medius and minimus are
paralysed, the patient cannot walk
normally.
• He sways or waddles on the
paralysed side to clear the opposite
foot off the ground.
• This is known as lurching gait; when it
is bilateral it is called as waddling
gait.
• However, if the abductor mechanism
is defective, the unsupported side of
the pelvis drops and this is known as a
positive Trendelenberg’s sign.
• The test is positive in defects of
power-
• i.e. paralysis of gluteus medius and
minimus;
• defects of fulcrum,
• abnormal weight transmission.

14. • All the three gluteal muscles are acting like ropes
running from the pelvis, going to the anterior,
posterior and lateral aspect of hip joint.
• This arrangement act as guy ropes (Guy means a rope
fixed to the ground to secure a tent).

16. L4
L5
S1
S2
S3
VENTRAL PRIMARY RAMI

17. Iliac crest
Gluteus maximus
Gluteus medius
Gluteus minimus
Pyriformis
Greater trochanter
Tricipital tendon
Quadratus femoris
Adductor magnus
Sacrotuberous ligament
Ischial tuberosity
Sciatic nerve
Tibial nerve Common peroneal nerve
Semimembranosus
Semitendinosus Long head of biceps femoris
COURSE AND RELATIONS OF SCIATIC NERVE

18. Sacral plexus
Pelvis
Gluteal region
Thigh
Tibial component
To hip joint Common peroneal component
To semitendinosus
To long head of biceps
To semimebranosus
To adductor magnus
To knee joint
L4
L5
S1 S2
S3
DISTRIBUTION OF TIBIAL COMPONENT OF SCIATIC NERVE

19. Sacral plexus
For knee joint
For short head of
biceps femoris
Common peroneal component
Sciatic nerve
Tibial component
L4
L5 S1 S2
Pelvis
Gluteal region
Back of thigh
DISTRIBUTION OF COMMON PERONEAL COMPONENT OF SCIATIC NERVE

20. APPLIED ANATOMY
Compression of
sciatic nerve

21. Foot drop

22. Sciatica

23. • Sleeping foot-
• It is the concussion of the
sciatic nerve when the
nerve is pressed against
femur by the hard surface
of the chair, the nerve is
damaged and leads to the
paralysis of the muscles
below the knee.
• MOTOR LOSS-
• The hamstrings are
paralysed but weak flexion
of knee is possible due to
the action of sartorius and
gracilis.
• All the muscles below the
knee are paralysed and the
weight of foot causes it to
assume the plantar flexed
position or foot-drop.

24. • SENSORY LOSS-
• There is loss of sensation below the knee, except
a narrow area along the medial side of the lower
part of the leg and along the medial border of the
foot upto big toe which is supplied by the
saphaneous nerve.
• TREATMENT-
• The result of operative repair of sciatic nerve
injury is poor.
• It is rare for active movements to return.
• Sensory recovery is rarely complete.
• Loss of sensation in the sole of the foot makes
the development of trophic ulcers.

25. • SCIATIC NERVE BLOCK-
• Sciatic block is an advanced nerve block
technique.
• The block is well suited for surgery on the
leg below the knee, particularly on the
ankle and foot.
• It provides complete anesthesia of the leg
below the knee with the exception of the
medial strip of skin, which is innervated
by the saphaneous nerve.

27. • DEFINITION-
• The group of muscles in the flexor compartment of the
thigh is called as hamstrings.
• WHY THEY ARE NAMED AS HAMSTRINGS-
• The word ‘Ham’ means the slender muscles of hip and
knee along with their tendons.
• These tendons of the animals are like pig, beef and goat
were used for stringing in bishop’s shops hence knows
hamstrings.
• Furthermore, in ancient times, it was common for soldiers
to slash their opponent’s horses posterior to the knees in
order to cut the tendons of their posterior thigh muscles.
This would bring the horse and its rider’s down.
• Also they use to cut these tendons of the soldiers so they
could not run; this was called as ‘hamstringing’ the enemy.

28. CHARACTERISTIC FEATURES-

29. CLASSIFICATION OF HAMSTRINGS-
True
Hamstrings
semitendi
nosus
semimemb
ranosus

30. CLASSIFICATION OF HAMSTRINGS-
Modified
Hamstrings
Long head
of biceps
femoris
Ischial
part of
adductor
magnus
Sacrotuber
ous
ligament
Tibial
collateral
ligament

31. • ACTIONS-

32. APPLIED ANATOMY

33. • As the two heads of biceps femoris have different nerve
supply a wound in the thigh may severe a nerve
paralyzing only one head and other being normal; this
will not affect the length of the muscle.
• In some people they are not long enough to allow them
to touch their toes when they flex the vertebral column
and keep their knees straight.
• In other people the hamstrings are long and they can
easily touch the floor with their palms.
• Tendon of semitendinosus is used in the rupture of the
anterior cruciate ligament for repair and replacement.