PELVIC GIRDLE & HIP
JOINT
Dance Anatomy and Kinesiology
By: Karen Clippinger
THE SPINE
The spine has four main sections:
The Cervical Spine – 7 Vertebrae
The Thoracic Spine – 12 Vertebrae
The Lumbar Spine – 5 Vertebrae
The Sacrum – 3-5 Fused
(and the Coccyx)
Vocabulary of the body to remember!
Superior
Above
Inferior
Below
Anterior
Forward of
Posterior
Behind
Medial
Inside
Lateral
Outside
BONES & BONY LANDMARKS
• The sides of the pelvis are termed the OS COXAE
• Each side is made up of 3 bones:
• Ilium (Groin), Ischium (Hip), Pubis (Genitals)
• They are fused and become a single bone at 15 or 16 years old
• ILIUM is a flat bone that is the largest of the three, forms the large upper side portion of
the pelvis
• Smooth concaved part of ilium is the ILIAC FOSSA, the superior convex border of the
ilium is the ILIAC CREST.
• Bony prominences forward of the Iliac crests are the ANTERIOR SUPERIOR ILIAC SPINE
(ASIS) and the bony prominences backward of the iliac crest are the POSTERIOR
SUPERIOR ILIAC SPINE (PSIS)
• KEY: for evaluating pelvis symmetry and alignment
BONES & BONY LANDMARKS
• ISCHIUM is an irregular bone that is the strongest of the three, located at the
lower posterior portion of the pelvis
• Most inferior portion of this bone has rough eminences, upon which we sit,
ISCHIAL TUBEROSITIES
• Key: This landmark is key for teaching turnout and pelvic alignment
• Thin flatten portion of Ischium is the RAMUS which ascends upward and
forward to join with the INFERIOR RAMUS of the pubis
• Pubis is an irregular bone located in the anterior and inferior portion of the
pelvis
• The thin and flatten SUPERIOR RAMUS ascends and joins with the ilium
• Together the RAMI and other parts of pelvis form a large opening called the
OBTURATOR FORAMEN
• Largest foramen in the body
• Attachment point for muscles and ligament key for effecting turnout
BONES AND
BONY LANDMARKS
Each Os Coxae contains a
cavity called acetabulum
which is where the head of the
femur (leg) attaches
BONES AND
BONY LANDMARKS
This is one area of the skeleton
were there are gender like
differences
JOINT STRUCTURE & MOVEMENTS
OF PELVIC GIRDLE
• The Os Coxae are joined firmly to the sacrum
posteriorly and to the sacroiliac joints AND
anteriorly to each other at the PUBIC
SYMPHYSIS forming one solid structure…The
PELVIC GIRDLE
• The pelvic girdle provides connection between
the lower limbs and the axial skeleton
• Also supports and protects vital lower
abdominal organs
• Public Symphysis (growing together), is a
cartilaginous joint and allows slight movement
for shock absorbency. During pregnancy
ligaments become lax to allow more
movement associated with pregnancy
JOINT STRUCTURE & MOVEMENTS
OF PELVIC GIRDLE
• Sacroiliac Joints (sacred), are the joints between the sacrum of the spine and
the right and left ilium.
•
•
•
•
They are quite stable due to the presence of many ligament attachments
Sacrum sits like a wedge between the ilia
Connection here adds stability and limits movement in certain directions
Common injury site in dancers
• Movements of the Pelvic Girdle
• The limited movement of the pubic symphysis and sacroiliac joints allows the pelvic
girdle to essentially function as a single unit
• Good for stability and protection and support pelvis functions
• Limiting in terms of movement and therefore the lower spine, the lumbosacral joint
become important for facilitating positional changes in the pelvis
• Anterior Tilt, Posterior Tilt, Lateral Tilt and Rotation
JOINT STRUCTURE & MOVEMENT
OF THE HIP
• In upright posture like walking or running, the weight of the body is
transmitted down through the spine and pelvis through one or both rotary
hip joints. In addition to withstanding these downward forces of gravity, the
hip joint also transmits forces from the ground to the pelvis.
• These important force transmission functions make joint stability and strength
a priority. However, sufficient mobility must be present to facilitate locomotor
movement.
• The joint architecture, with its unique arrangements to muscles and ligaments
helps meet the bias of stability while allowing adequate mobility.
JOINT STRUCTURE & MOVEMENT
OF THE HIP
• Hip Joint Classification and Associated Movements
• The hip joint, the actebularfemoral joint, is a balland-socket joint which is formed between the
acetabulum and the head of the femur
• Due to the depth of the socket and broad
surface areas of contact between the
articulating bones, joint stability is favored
• Approx 70% of the femur articulates with the
acetabulum
• In contrast only 25% of the head of the humerus
(arm) contacts with the shoulder socket
• Classic ball-and-socket joints have 3 degrees of
freedom of motion
• Flexion-Extension
• Abduction-Adduction
• External-Internal Rotation
• Photos: Page 162
JOINT STRUCTURE & MOVEMENT
OF THE HIP
• Hip Joint Capsule and Key Ligaments
• A strong, dense capsule, encloses the
entire hip joint. It attaches from the
actebulum and runs distally (away from
the hip) to the neck of the femur,
encasing it like a tube. The capsule has
thickened ligamental bands that spiral
around the neck of the femur named:
Iliofemoral, pubofemoral and
ischiofemoral ligaments.
• Due to their tight spiral arrangement,
they become important for providing
stability in upright standing
• Photos: Page 163
JOINT STRUCTURE & MOVEMENT
OF THE HIP
• ILIOFEMORAL LIGAMENT is located at the front of the hip joint, spiraling inferiorly from the anterior
inferior iliac spine of the pelvis to diverge into two bands that attach to the upper and lower
portions of the intertrochanteric line.
•
•
•
•
•
Sometimes called the “Y” ligament, because of it appearance
One of the strongest ligaments in the body
Plays a very important role while standing
Gravity generally passes behind center of rotation and extends the hip joint
Iliofemoral joint become taut w/hip extension and allows standing to be maintained
• Prevents the trunk from falling backward or the head of the femur from displacing anteriorly
• Serves as powerful constraint in bring leg behind you, like tendu or arabesque
• Limits hyperextension to 10 or 20 degrees but dancers have increased this to 40 degrees
• Due to the restraint some dancers adopt the undesired tactic of anteriorly tilting the pelvis when trying to
achieve greater turnout
• PUBOFEMORAL LIGAMENT is located on the anterior and lower portion of the capsule and runs
between the pubic bone and an area near the less trochanter
• Assists iliofemoral ligament in limiting hip extension and external rotation.
• ISCHIOFEMORAL LIGAMENT is located at the posterior part of the hip and provides protection
from posterior displacement of the femur. It spans between the ischium and just below the
acetabulum
• Prevents hip internal rotation and horizontal adduction
JOINT STRUCTURE & MOVEMENT
OF THE HIP
• Specialized Structures of the Hip
• Various structures provide joint stability and aid in joint function
• Acetabular Labrum (lip shaped structure), is a specialized rim of fibrocartilage that is
considerably thicker at the circumference, thus increasing the depth of the acetabulum
and helping hold the head of the demur in place.
• This thickness also provides cushioning for the top and back of the acetabulum against large
compression forces of the head of the femur.
• This Labrum improves joint stability and protects the bone
• Suction: There is a difference of atmospheric pressure in the hip joint, similar to a vacuum
that pulls the head of the femur into the socket
• The depth of the acetabulum, the presence of the acetabular labrum and suction keep
the joint in tack
• Even if all the muscles and ligaments were cut, the joint will stay together (45lbs, 90lbs)
• Bursae: (liquid sack) Two most common bursae that are inflamed in dancers are, 1
located over the greater trochanter and 2 between the iliopsoas and the underlying
articular capsule
• Muscles: In addition, many strong muscles cross the hip joint and provide stabilization.
These muscles are much larger and stronger than those in the upper extremity
PELVIS VOCABULARY
• Os Coxae
• Obturator Foramen
• Ilium
• Pubic Symphysis
• Iliac Fossa
• Iliofemoral Ligament
• Iliac Crest
• Pubofemoral Ligament
• Anterior Superior Iliac Spine
• Ischialfemoral Ligament
• Posterior Superior Iliac Spine
• Acetabular Labrum
• Ischium
• Suction
• Ischial Tuberosity
• Bursae
FUNCTIONS OF INDIVIDUAL HIP
MUSCLES
• 22 Muscles Cross the Hip Joint
•
•
•
•
The Anterior muscles are hip flexors
The Posterior muscles are hip extensors (except the deep rotator muscles)
The Lateral group are hip abductors
The Medial group are hip adductors
• Although the primary action is the same their secondary action may differ
• Keep in mind the hip has 3 degrees of motion and many muscles will use all
three simultaneously, however 1 or 2 often dominate
• Also, the action of a muscle may differ with changes in the joint angle due to
the shift in the line of pull relative to the axis
ALIGNMENT & COMMON
DEVIATIONS OF THE HIP REGION
• Alignment of the bones in the hip region influence the bones above and below the
pelvis and hip joint.
• For Example, the alignment of the pelvis will influence the spine above and the knee,
ankle and foot below
• Three Alignment Considerations are particularly important
• Pelvic Inclinations/Pelvic Tilts
• The angle of femoral inclination
• The angle of femoral torsion
• Position of the Pelvis is NEUTRAL -> Deviations
• Anterior & Posterior Tilts
• Right & Left Lateral Tilts
• Right & Left Rotations
• To identify pelvic alignment these bony landmarks are used:
• Iliac Crest, ASIS, PSIS, Pubic Symphysis
INDIVIDUAL MUSCLES OF THE HIP
• Anterior
pg. 165, 166
• These muscles cross anterior to the axis of the hip joint for flexion-extension
• Common action used in walking, running, leaping
• Illiopsoas, Rectus Femoris, Sartorius
• Posterior
pg. 167-169
• Gluteus Maximus, Iliotibal band, Hamstrings, Deep Outward Rotators
• Lateral
pg. 171
• Gluteus Medius & Minimus, Tensor Fasciae Latae
• Medial
pg. 172, 173
• Adductor Longus, Adductor Brevis, Adductor Magnus, Pectineus, Gracilis
• View pages for photos
INDIVIDUAL MUSCLES OF THE HIP
ANTERIOR MUSCLES
•
•
•
•
•
•
•
•
•
•
ILIOPSOAS – Psoas Major and Iliacus
They share a common distal attachment
Appear to act together in movement, hence, iliopsoas
16 inches long
Runs deep under the abs from the front of the lower spine and inner portion of the
illium downward to attach onto the medial side of the upper femur at the lesser
trochanter
Hard to feel because of how deep it sits
One of the most powerful muscles in the body, can develop to pull 1000lbs
Most important muscle in hip flexion above 90 degrees
Assists with hip abduction at higher ranges (high developpes front or side)
Only muscles in the human body that attaches to the spine, pelvis and femur
• Due to this: Iliopsoas stabilizes the hip and effects position of lumbar spine
• Prevents the torso from falling backward, maintains lumbar curve
INDIVIDUAL MUSCLES OF THE HIP
• RECTUS FEMORIS – 1 of the 4 Muscles that make up your quadriceps femoris
• Only member of the group that crosses the hip joint
• Rectus means straight, therefore rectus femoris runs straight down the front of the
femur
• Flexes the hip and extends the knee
• This combination of hip flexion and knee extension gave name “kicking muscle”
•
•
•
•
•
•
SARTORIUS – The longest muscle in the body
Slender, runs from front of pelvis down thigh to attach medially to the tibia
Assists Hip flexion and also abducts and can externally rotate the hip
Commonly called “tailor’s muscle” – Sartor = a tailor
Combination of motions in dance would be passe’
Due to long, thin composition, it is designed for speed rather than strength
• Making it a common injury site for dancers
• Can also produce flexion or internal rotation of the knee
INDIVIDUAL MUSCLES OF THE HIP
POSTERIOR MUSCLES
• GLUTEUS MAXIMUS – Largest, most superficial of the buttocks muscles
• Forms the roundness of the back of the buttocks
• Large size in humans thought to be due to demands of upright stance
• Most powerful hip extensor
• Which is crucial for movements like walking up stairs, hills, running, jumping
• In addition to hip extension, also can produce hip external rotation
• Due to insertion to the ilotibial band (a strong fascia of the lateral thigh that
spans between the pelvis and lower leg) the gluteus maximus indirectly helps
support the femur upon the tibia
• HAMSTRINGS – form the bulk of the back of the thigh
• Composed of 3 muscles: Biceps femoris, semitendinosus, deeper
semimembranosus
INDIVIDUAL MUSCLES OF THE HIP
POSTERIOR MUSCLES
• HAMSTRINGS – (Continued)
• Their action of extension comes into play with everyday movements
• Standing, walking, controlling forward motion of the torso
• Function is considered more postural and fine-tuning
• Whereas the Gluteus is more power
• All 3 muscles attach distal to the knee & act as knee flexors and hip extensors
• BICEPS FEMORIS (lateral) – particularly active in hip extension considered to be
“workhorse” for hip extension
• Insert laterally to tibia and fibula
• Assist with knee external rotation or hip external rotation when the hip and knee are
extended
• SEMITENDENOSUS & SEMIMEMBRANOSUS (medial) insert into medial part of the tibia
• Assist with knee internal rotation or hip internal rotation when the hip and knee are
extended
INDIVIDUAL MUSCLES OF THE HIP
POSTERIOR MUSCLES
• DEEP OUTWARD ROTATOR MUSCLE GROUP
• Piriformis, Quadratus Femoris, Obturator Internus, Obturator Externus, Gemellus Superior,
Gemellus Inferior
•
•
•
•
•
These 6 muscles are deep into the gluteus
Fiber run horizontally, spanning from inside to outside
PIRIFORMIS, most superior of the group is located slightly above hip joint
QUADRATUS FEMORIS, most inferior is located slightly below the hip joint
OBTURATOR INTERNUS & GEMELLI are located between the two
• Obturator Internus has extensive attachments to internal surface membrane covering
the obturator foramen and surrounding areas
• Obturator Externus has extensive attachments to external obturator surface membrane
and adjacent bones
• Gemellus Superior accompanies above
• Gemellus Inferior accompanies below
• Together referred to as Three-Headed Muscle – Triceps Coxae
INDIVIDUAL MUSCLES OF THE HIP
POSTERIOR MUSCLES
• DEEP OUTWARD ROTATOR MUSCLE GROUP
• Function as a group
• Help hold the head of the femur and the acetabulum
• Help prevents upward jamming of the femur with hip abduction
• Most known for action in hip external rotation
• Ability of muscles group to produce hip external rotation without other motions
makes this key for the production and maintenance of turnout
• When at 90 degrees some muscles are in an effective position to produce hip
horizontal abduction
• Passe’
• Rond de jambe en l’air
• Binder Order – Quarter 1
• Syllabus
• Supply List
• Ballerina*
• Objectives - week of Sept 9 – Oct 21
• Muscle Packet
• Ballet Vocabulary
• Muscle Vocabulary 1-20
• Quiz 1 - Muscles
• Muscle Vocabulary 21-40
• **Muscle notes or in class assignments
• Progress Report
• Test 1 - Muslces
• Pelvis Packet
• Pelvis Vocab
• Quiz 2 – Pelvis
• **Any make up work
• **Items with double stars are not required to be in the binder