Dance Kinesiology Exam 2

Bones and Bony Landmarks of Pelvis and Femur

Os Coxae: composed of 3 bones
1. Ilium
2. Ischium
3. Pubis

Joints of the pelvis and hip

pubic symphysis
sacroiliac joint
acetabulofemoral joint

pubic symphysis

-Cartilaginous joint formed by
fibrocartilaginous disc that unites
right and left pubis
-Heavily reinforced by ligaments

sacroiliac joint

-Articulation between the concave
sacrum and convex ilium
-Strong ligaments and muscles make
this joint strong. Very little
movement occurs here; this is an
area of controversy.

Movement of the pelvic girdle

Anterior/posterior tilt
Right/left tilt
Right/left rotation

anterior pelvic tilt

sagittal plane/frontal axis, ASIS moves forward relative to pubis

posterior pelvic tilt

sagittal plane /frontal axis, ASIS moves backwards relative to pubis

right lateral pelvic tilt

R ASIS and PSIS lowers in the frontal plane

Left lateral pelvic tilt

L ASIS and PSIS lowers in the frontal plane

Right pelvic rotation

R ASIS is moving backwards/L ASIS is moving forward in the horizontal plane

Left pelvic rotation

L ASIS is moving backwards/R ASIS is moving forward in the horizontal plane

Acetabulofemoral Joint

• Articulation of the acetabulum
and the head of the femur
• Ball and socket joint
• Ligaments:
• Pubofemoral ligament
• Iliofemoral ligament
• Ischiofemoral ligament

Acetabulofemoral Joint Ligaments

Anterior: Iliofemoral ligament, pubofemoral ligament
Posterior: Ischiofemoral ligament

Acetabular labrum

specialized rim of fibrocartilage on the margins of the acetabulum

Acetabular labrum function

• Increases the area contact for the
femoral head
• Increases stability by “gripping” the
femoral head and deepening the socket
• Creates seal to help maintain synovial
fluid
• Aides in suction to promote joint stability

Bursae/bursa

-Fluid filled sacs that are present to reduce friction
-Acts as a cushion between ligaments, muscles, bones and dissipates force

Three main types of bursa

synovial, adventitious, and subcutaneous

synovial bursae

are most commonly found and lie near the synovial membrane of the joints of your body.

adventitious

The accidental bursa occur only after continued shearing or repeated pressure over a bony prominence. A bunion is an example of an adventitious bursa.

subcutaneous

These bursae lie between your skin and a bony prominence and allow friction-less motion of your skin over the bone. An example of this can be found on the back of the elbow.

movements of the acetabulofemoral joint

medial/lateral rotation, flexion/extension, abduct/adduct

anterior muscles of the hip

iliopsoas, rectus femoris, and satoris

iliopsoas attachments

Proximal: sides of T12 and all lumbar vertebrae, inner surface of ilium
Distal: upper femur (lesser trochanter)

iliopsoas action

hip flexion
hip abduction (higher ranges)

rectus femoris attachments

Proximal: Anterior head: ilium (anterior inferior iliac spine)
Posterior head: just above the acetabulum
Distal: Upper tibia (tibial tuberosity) via the patellar tendon

anterior acetabulofemoral joint ligaments prevent what?

head of femur coming forward

posterior acetabulofemoral joint ligaments prevent what?

head of femur coming back

tear in labrum may not because

it has a poor blood supply

rectus femoris actions

hip flexion
knee extension

satorius attachments

Proximal: Anterior superior iliac spine (ASIS) and area just below
Distal: Medial surface of upper tibia (pes anserinus)

satorius actions

hip flexion
hip abduction
hip external rotation
knee flexion

posterior muscles of the hip

gluteus maximus
hamstring
deep external rotator

gluteus maximus

most powerful hip extensor

gluteus maximus attachments

Proximal: posterior ilium, sacrum, and coccyx
Distal: posterior aspect of upper femur (below greater trochanter) and iliotibial band

gluteus maximus actions

hip extension
hip external rotation

iliotibial band

Strong fibrous band, thickening of the fascia on the lateral surface of thigh. Receives the distal aspects of the gluteus maximus and tensor fasciae latae (TFL) m. Helps to laterally stabilize the hip and knee.

hamstring muscles

biceps femoris, semitendinosus, semimembranosus

biceps femoris attachments

Proximal: Long Head: ischial tuberosity
Short head: Posterior aspect of lower femur
Distal: lateral aspect of upper fibula and tibia

semitendiosus attachements

proximal: ischial tuberosity
distal: medial surface of upper tibia (pes anserinus)

semimembranosus attachements

proximal: ischial tuberosity
distal: posterior aspect of upper tibia

biceps femoris actions

hip extension
hip external rotation
knee flexion

semtendinosus and semimembranosus actions

hip extension
hip internal rotation
knee flexion

deep outward rotators of the hip

piriformis, obturator externus, gemellus superior, obturator internus, gemellus inferior, and quadratus femoris

piriformis attachments

Proximal: anterior surface of sacrum, posterior ilium
distal: superior surface of greater trochanter of femur

actions of 6 deep rotators

external hip rotation

obturator externus attachments

Proximal: external surface of obturator membrane and adjacent pubis and ischium
Distal: adjacent to upper greater trochanter (trochanteric fossa)

gemellus superior

Proximal: posterior, lower part of ischium
distal: gemelli and obturator internus via a common tendon to medial aspect of greater trochanter of femur

obturator internus

proximal: internal surface of obturator membrane, ischium
distal: gemelli and obturator internus via a common tendon to medial aspect of greater trochanter of femur

gemellus inferior

proximal: ischial tuberosity
distal: gemelli and obturator internus via a common tendon to medial aspect of greater trochanter of femur

quadratus femoris

proximal: lateral ischial tuberosity
distal: the crest between the greater and lesser trochanter on posterior femur

lateral muscles of the hip

gluteus medius, gluteus minimus, and tensor fascia latae

gluteus medius

powerful hip abductor and important pelvic stabilizer

gluteus medius attachments

proximal: upper outer surface of ilium
distal: lateral surface of greater trochanter of femur

gluteus medius and minimus actions

hip abduction
hip internal rotation

gluteus minimus attachments

proximal: lower outer surface of ilium
distal: anterolateral aspect of greater trochanter or femur

Tensor Fasciae Latae attachments

proximal: lateral aspect of ASIS and adjacent outer iliac crest
Distal: tibia via iliotibial band

tensor fasciae latae actions

hip abduction, hip flexion, hip internal rotation

medial muscles of the hip

adductor longus, adductor brevis, adductor magnus, pectineus, and gracilis

adductor longus attachments

proximal: anterior pubis
distal: middle third of linea aspera of femur

adductor longus and brevis actions

hip adduction, hip flexion (lower ranges)

adductor brevis attachments

proximal: inferior pubis
distal: upper third of linea aspera of femur

adductor magnus attachments

proximal: inferior pubis and ischium
distal: length of linea aspera and projection on lower femur (adductor tubercle)

adductor magnus actions

hip adduction, hip flexion (anterior fibers), hip extension (posterior fibers)

pectineus attachments

proximal: superior pubis
distal: upper shaft of posterior femur (line between lesser trochanter and the linea aspera)

pectineus actions

hip adduction and hip flexion

gracilis attachments

proximal: pubis
distal: medial surface of upper tibia (pes anserinus)

gracilis actions

hip adduction, hip flexion (lower ranges), knee flexion

angle of femoral inclination

angle between the neck of the femur and shaft

coxa vara

angle is abnormally decreased

coxa valga

angle is abnormally increased >125 degrees (bent outwards)
increase risk of subluxation/dislocation
decreased effectiveness of hip abductor muscles
increased range of hip abduction

normal angle of femoral inclination

120-135 degrees

angle of femoral torsion

rotation of the neck of the femur in the transverse plane

normal angle of femoral torsion

rotated anteriorly 8-15 degrees relative to the femoral condyles

femoral anterversion

neck of femur is angled more forward
person will generally inwardly rotate from hips to achieve better position of femur in the acetabulum.
• Inward facing knees and feet “in- toeing”
• Restricted hip external rotation

femoral retroversion

neck of femur angles posteriorly
decreased contact within acetabulum, increased risks for labrum tear
• Creates an “out-toeing”
• Greater hip external rotation

Lumbopelvic rhythm

describing the relationship of spine, hip and femur in CKC
Ex: Roll down
• Head initiates > cervical flexion> thoracic flexion> lumbar flexion> anterior tilt> acetabulofemoral flexion

Pelvic-femoral rhythm

describing the relationship of spine, hip and femur in OKC.
• Ex: natural response to posteriorly tilt pelvis in G. battement or anterior tilt with
arabesque

Important lumbo-pelvic stabilizers

transverse abdominus m., gluteus medias m. ,
hamstring mm., gluteus maximus m.

force couple

when 2 or more muscles on opposing sides of joint work together to create joint stability

Triad of muscles for turn out

abdominals, adductors, deep rotators

abdominals

activate from pubic bone to rib cage, lumbar spine is in
neutral, back and glutes relaxed

adductors

brings inside of thigh foward

deep rotators

turnout hip without changing pelvic alignment

proper elongation of appropriate postural muscles

iliopsoas m. and erector spinae mm.

hip injuries in dancers

7-14% of dance injuries occur in the hip
• Contributing factors:
• Turnout- increases stress on anterior structures of
the hip
• Excessive stretching leads to capsule ligamentous
laxity>>instability
• Extensive ROM
• Repetitive flexion, extension with abduction and ER
• Hypermobility

common injuries in the hip for dancers

• Acetabular Labral Tear
• Hamstring Muscle strains
• Snapping Hip Syndrome
• Piriformis Syndrome
• Sacroiliac Joint Pain Syndrome

what causes a labral tear to not heal?

poor vascular

what does the labrum do?

increase surface area
joint stability
suction

Snapping Hip Syndrome

characterized by a palpable or audible snapping or clicking
in one or both hip joints
• Two types: external (most common) and internal

External: external extra-articular coxa saltans (snapping hip)

• involves either the posterior Iliotibial band (IT band) or the anterior
part of the gluteus maximus catching and “snapping” over the greater
trochanter
• Usually indicates that the IT band or the Gluteus maximus m. is tight
• Gradual onset
• Can be associated with IT band syndrome and trochanteric bursitis
• Possible contributing factors:
• prominent greater trochanter, coxa vara, Fibrotic scar tissue, Smaller lateral pelvic
width, Past issues with and surgeries for anterolateral knee instability

Internal Snapping Hip

The iliopsoas tendon snaps over a protrusion in the pelvic bone or the
rectus femoris snaps over the the femoral head
• often associated with iliopsoas bursitis
• Symptoms:
• Sudden, sharp pain deep within the front of the groin during hip flexion,
extension or external rotation
• Pain that worsens with activity
• Pain that worsens slowly over time
• Hip pops from running, standing up from a seated position or when the hip
rotates the leg outward, away from the body
• Snapping causes audible click or pop

piriformis syndrome

pain and numbness in your buttocks and down the back of your leg.

Sacroiliac Joint Pain

Pain around the SI joint (unilateral or
bilateral)
• May be due to inflammation, trauma,
mechanical dysfunction
• Not well understood in literature

trendelenburg test

a physical examination finding seen when assessing for any dysfunction of the hip

2 joints of the knee

tibofemoral joint and patellofemoral joint

tibiofemoral joint

•Articulation between the distal femur and proximal tibia.
medial and lateral condyles of the femur and the articular surfaces of the tibial
plateau
•Synovial joint: articular surfaces are covered with cartilage that reduces friction, aides
with absorption of forces
•Hinge joint: flexion and extension in sagittal plane/frontal axis
•Some rotation with the joint is flexed

Tibiofemoral jt.
Capsule and Ligaments

•Surrounded by extensive joint capsule
further supported by ligaments

4 primary ligaments of the tibiofemoral joint

•Medial collateral ligament
•Lateral collateral ligament
•Anterior Cruciate Ligament
•Posterior Cruciate Ligament

medial collateral ligament (mcl)

•broad, flat, fan-shaped collateral ligament on medial aspect of knee
•Joints medial condyles of femur to tibia
•Key for medial stability, resists valgus stress and limits rotation

Genu

knock knees (knees turned in medially)