Class #3

Pelvis Supports the trunk and organs in the lower

abdomen (pelvic cavity) Absorbs stress from lower limbs when

moving (walking/jumping) Female pelvis is adapted for pregnancy and

childbirth and is wider and lighter than male pelvis

Bones of the pelvis Ilium-forms superior flared portion,

impt.for muscle attachment Ischium- inferior portion and strongest

bone of the pelvis Pubis- anterior portion of pelvis

Landmarks of the Pelvis: Iliac crest Iliac fossa Ant.Superior Iliac Spine (ASIS) Ant. Inf. Iliac Spine (AIIS) Post. Sup. Iliac spine (PSIS) Post. Inf. Iliac spine (PIIS) Greater Sciatic Notch Gluteal Lines

Ischium Ischial tuberosity (what you are sitting on) Ischial spine Lesser sciatic notch Ramus of the ischium (ramus=branch)

Pubis Pubic crest Pubic symphysis Superior ramus of pubis Inferior ramus of pubis

Acetabulum On lateral pelvis where ilium, ischium, and

pubis fuse and create a deep socket; articulates with the head of the femur to form the hip joint(coxal, hip socket)

Obturator foramen Sacrum Coccyx

Quadriceps GroupMain action is to extend the leg at the knee

joint (kicking a ball) also to move the thigh into extension at the knee; standing up from seated position, coming up into straight leg position from squat

Quad=four; cep=headed

Quadriceps muscle Rectus Femoris Vastus Lateralis Vastus Medialis Vastus Intermedius

About Muscles O: (Origin)- Where the muscle begins I: (Insertion)- Where the muscle ends A: (Action)- This is what the muscle does

when it contracts or shortens.

Insertions point always moves close to the origin.

Extension of the leg at the Knee Rectus femoris Vastus lateralis Vastus medialis

Vastus intermedius

Quadriceps Rectus FemorisRectus=straight or upright;Femoris=related to thighOrigin: AIISInsertion: Tibial Tuberosity, via the patella and patellar

ligamentAction: Ext. of the leg at the knee joint

Flexion of the thigh at the hip jointCombined actions seen as leg is brought forward in walking.

Quadriceps Vastus Lateralis

Vastus=vast or large; lateralis=related to the side

O: Linea aspera, ant. Aspect of greater trochanter

I: Tibial tuberosity, via patella & patellar lig.

A: Ext. of the leg at knee joint(also restrains medial pull on patella by Vastus Medialis)

Quadriceps Vastus Medialis (Medialis=related to the

middle

O: linea aspera

I: Tibial tuberosity via the patella & patellar lig.

A: Ext. of the leg at knee joint

Quadriceps Vastus Intermedius (intermedius=among the

middle, intermedius lies deep to the other quadriceps muscles.

O: linea aspera, anterior and lateral femoral shaft.

I: Tibial tuberosity via the patella & patellar lig.

A: Ext. of the leg at the knee joint

All 4 muscles are innervated by the Femoral Nerve

All 4 have common insertion on the tibial tuberosity

Osgood-Schlatter Dz Irritation and inflammation of the tibial

tuberosity; most often in boys between 10-15. The tuberosity becomes inflammed and/or separates from tibia, because of irritation caused when patellar tendon pulls on tuberosity during periods of rapid growth or overuse of quadriceps.

Medial Thigh MusclesAdduction of the Hip

Adductor magnus Adductor longus Adductor brevis

Gracilis Pectineus

Psoas major Iliacus

Gluteus maximus (lower fibers)

Adductor group Muscles of medial thigh Main action is hip adduction Also do medial rotation of hip, and all but

Gracilis assist with hip flexion

Adductor Muscles Pectineus Adductor Longus Adductor Brevis Adductor Magnus Gracilis Sartorius

Adductor Muscles Pectineus (means related to the pubic bone)

O: Ring around the obturator foramen (ant. Pubis)

I: linea aspera

A: adduction of femur at hip joint

Flexion of femur at hip joint

Adductor Muscles Adductor Longus

O: Ring around the obturator foramen (ant. Pubis)

I: linea aspera

A: adduction of femur at hip joint

assists with flexion of femur at hip

Adductor Muscles Adductor Brevis

Brevis is deep to longus

O: ring around the obturator foramen (ant. Pubis)

I: linea aspera

A: adduction of femur at hip joint

assist with flexion of femur at hip

Adductor Muscles Adductor Magnus (magnus=great)

Largest and deepest

O: ring around obturator foramen (inf. Ramus of pubis and ramus of ischium, ischial tuberosity)

I: linea aspera; (gluteal tuberosity, adductor tubercle of femur)

A: adduction of femur at hip

assists with ext. of femur at hip

Adductor Muscles Gracilis = slenderO: ring around the obturator foramen (inf ramus of

ant. Pubis)I: Proximal anteromedial tibia at the pes anserinus

tendon.A: adduction of femur at hip joint

assists with medial rotation of hipassists with flexion of leg at kneeassists with medial rotation of leg at knee

Adduction musclesCommon origin: ring around obturator

foramen

Common insertion: linea aspera

Nerve to adductor muscles is the Obturator

Adductor Muscles Sartorius “tailor’s muscles”Longest muscle in body, most superficial thigh muscleO: ASISI: proximal anteromedial tibia at the pes anserinusA: hip: assists with flexion

abductionLateral rotaton

Knee: assists with flexion, and medial rotation of leg at knee

Posterior Thigh MusclesFlexion of the leg at the knee

Biceps femoris Semitendinosus

Semimembranosus Gracilis

Sartorius Gastroncnemius

Popliteus Plantaris

Hamstring Group Named so because butchers used to hang

the carcass of a pig by the hamstring tendons.

Cross two joints: hip and knee, so involved with flexing leg at knee joint and extending femur at hip joint.

Hamstring Muscles Biceps Femoris Semitendinosus Semimembranosus

Hamstrings Muscles Biceps Femoris:

Biceps=two headed; femoris=related to thigh

O: Long head-ischial tuberosity

Short head-linea aspera

I: head of the fibula (lateral aspect)

A: Long head: ext. of femur at hip

Long and Short heads: flexion of leg at knee

lat. Rotation of leg at knee

Hamstring Muscles Semitendinosus:

Means half tendon

O: ischial tuberosity

I: pes anserinus (proximal anteromedial tibia)

A: flexion of leg at knee joint

med. Rot. Of leg at knee joint (knee must be semiflexed for medial rot. To occur)

ext. of femur at hip joint

Hamstring Muscles Semimembranosus

Means half membrane

O: ischial tuberosity

I: posteromedial tibial condyle

A: flexion of leg at knee joint

med. Rot. Of leg at knee joint(knee must be semiflexed for med. Rot. To occur)

extension of femur at hip joint

Hamstring MusclesCommon origin of all hamstring muscles is

the ischial tuberosity(your sits bone).

Pes Anserinus (the proximal anteriomedial tibia)

The common insertion for three thigh muscles

Anterior- Sartorious

Medial- Gracilis

Posterior- Semitendinosus

Flexion of the thigh at the hip Rectus Femoris

Gluteus medius (ant. fibers) Gluteus minimus

Adductor magnus (assists) Adductor longus (assists) Adductor brevis (assists)

Pectineus (assists) TFL

Sartorius Psoas major

Iliacus

Extension of the thigh at the hip Biceps femoris

Semitendinosus Semimembranosus Gluteus maximus

Gluteus medius (post. fibers) Adductor magnus (post. Fibers)

End of Class 3