Week 9 - Spine, Pelvis, and Hip

Why would an injury at one spinal level not completely effect a muscle's function?

Most muscles innervated by more than 1 spinal level

Key muscle innervated by C3

Diaphragm

Key muscle(s) innervated by C5

Shoulder abductors, elbow flexors

Key muscle innervated by C6-8

Wrist extensors

Key muscle innervated by C7-8

Triceps

Key muscle innervated by C8-T1

Hand intrinsics

Key muscle(s) innervated by T spine

Each spinal level innervates muscles at that level (think abs)

Key muscle(s) innervated by L2-4

Hip flexors, knee extensors

Key muscle(s) innervated by L2-3

Hip adductors

Key muscle(s) innervated by L4-5

Hip abductors

Key muscle(s) innervated by L5-S2

Hip extensors, knee flexors

Key muscle(s) innervated by L4-S2

Ankle motion

Key muscle(s) innervated by S4-5

Bowel and bladdder

Myotomes

Muscle groups innervated by spinal nerve roots

Dermatomes

Skin (sensory) areas innervated by specific spinal nerves

2 Classifications of sensory receptors

Mechanoreceptors—responds to mechanical deformation of receptor

◦ touch, pressure, stretch, vibration

Chemoreceptors—responds to chemicals or substances released from cells

◦ damaged cells following injury or infection

Thermoreceptors—responds to heating or cooling

What can cause damage to nerves (peripheral neuropathies)?

Single event trauma

◦ Laceration

◦ Electrical shock

Repetitive stimuli

Prolonged compression

Wounds/infections

Stretch ischemia

General categories of traumatic neuropathies based on severity

Traumatic myelinopathy

• myelin damage

Traumatic axonopathy

• axonal damage

Severance

• axon and myelin degeneration

L1-L4 refered to as the _____________

Lumbar plexus

L4-L5 referred to as the _________________

Lumbosacral trunk

L5-S3 referred to as the __________________

Sacral plexus

The sciatic nerve is composed of these two things

Common fibular nerve, tibial nerve

Four joints of the pelvis

-Pubic symphysis (ant)

-Lumbosacral (post)

-Sacroiliac

-Sacrococcygeal

Which is the monst commonly affected joint in lumbar spinal disorders and where is it located?

-Lumbosacral joint

-Secondary cartilaginous joint between L5

and S1 vertebrae via the L5/S1

intervertebral disc

What reinforces the lumbosacral joint?

A series of strong anterior and posterior longitudinal ligaments

Function and joint types of sacroiliac joint

-Weight transfer between femur and axial skeleton

-Anterior portion is synovial

-Posterior portion is a syndesmosis

How is the sacroiliac joint connected to the axial skeleton?

A series of strong ligaments

Joint type and functions of sacroiliac joint

-Secondary catilaginous joint

-May contribute to increase/decrease of

pelvic outlet size during defecation and

labor

-Attachment of pelvic floor muscles

Closed packed position of the hip

Extension, IR, abduction

Open packed position of the hip

Happy baby (90' flexion, abduction, ER)

What bones make up the acetabulum and what provides shock absorption?

-Ilium, ischium, pubis

-Acetabular labrum

The knee is also known as the __________________ joint

Tibiofemoral

Primary weight-bearing bone in the leg

Tibia

Closed packed position of tibiofemoral joint

Extension and tibial ER

Open packed position of tibiofemoral joint

30' knee flexion

Movements of the patellofemoral joint with knee flexion and extension

-Knee Flexion: patella glides inferior and medial

-Knee Extension: patella glides superior and lateral

Which hip compartment is responsible for hip flexion?

Anterior

Which hip compartment is responsible for hip extension?

Posterior

Which hip compartment is responsible for hip adduction?

Medial

Which hip compartment is responsible for hip abduction?

Lateral

Iliacus OIAN

◦ O: Iliac fossa

◦ I: Lesser trochanter of

femur

◦ A: Hip flexion, Lumbar

spine ipsilateral lateral

flexion

◦ N: Femoral n

Psoas major OIAN

◦ Origin: T12-L5

vertebrae

◦ Insertion: Lesser

trochanter of femur

◦ Innervation: Lumbar

plexus

◦ Action: Hip flexion,

Lumbar spine ipsilateral

lateral flexion

Sartorius OIAN

Origin: ASIS

Insertion: Pes anserine of knee

Innervation: Femoral n

Action:

Hip flexion, ER, abduction, Knee

flexion

Rectus femoris OIAN

Origin: ASIS

Insertion: Tibial tuberosity via patellar

tendon

Innervation: Femoral nerve

Action

◦ Hip flexion

◦ Knee extension

Gluteus maximus OIAN

Origin:

◦ Sacrum, ilium

Insertion:

◦ Iliotibial tract

◦ Gluteal tuberosity

Innervation: Inferior gluteal n

Action

◦ Hip extension/ hyperextension

◦ Hip ER

Semitendinosus OIAN

Origin: Ischial tuberosity

Insertion: Pes anserine

Innervation: Sciatic n

Action

◦ Hip extension

◦ Knee flexion

Semimembranosus OIAN

Origin: Ischial tuberosity

Insertion: Posterior surface of

medial condyle of tibia

Innervation: Sciatic n

Action

◦ Hip extension

◦ Knee flexion

Biceps femoris long and short head OIANs

Origin

◦ Long head = ischial tuberosity

◦ Short head = lateral aspect of linea aspera

Insertion

◦ Head of the fibula

Innervation

◦ Long head = sciatic n

◦ Short head = common fibular n

Action

◦ Long head = hip extension, knee flexion

◦ Short head = knee flexion

Pectineus OIAN

Origin:

◦ Superior pubic ramus

Insertion:

◦ Pectineal line of femur

Innervation:

◦ Femoral n

Action

◦ Hip adduction

◦ Small role in flexion

Adductor longus OIAN

Origin:

◦ Pubis

Insertion:

◦ Middle 1/3 of linea aspera

Innervation:

◦ Obturator n

Action

◦ Hip adduction

Adductor brevis OIAN

Origin:

◦ Pubis

Insertion:

◦ Pectineal line and proximal of linea aspera

Innervation:

◦ Obturator n

Action

◦ Hip adduction

Adductor magnus OIAN

Origin:

◦ Ischium & pubis

Insertion

◦ Hamstring portion = Linea aspera

◦ Adductor portion = adductor tubercle

Innervation

◦ Hamstring portion = Sciatic n

Adductor portion =

◦ Obturator n

Action

◦ Hip adduction

Gracilis OIAN

Origin:

◦ Pubis

Insertion:

◦ Pes anserine

Innervation:

◦ Obturator n

Action

◦ Hip adduction

Obturator externus OIAN

Origin:

◦ Outer surface of obturator membrane/foramen

Insertion:

◦ Between greater and lesser trochanters

Innervation:

◦ Obturator n

Action

◦ Hip adduction and ER: One of the "deep hip rotators"

Gluteus medius OIAN

Origin:

◦ Outer surface of ilium

Insertion:

◦ Lateral surface of greater trochanter

Innervation:

◦ Superior gluteal n

Action

◦ Primary = Hip abduction

◦ Secondary = ER/IR

Gluteus minimus OIAN

Origin:

◦ Outer surface of ilium, deep to gluteus medius

Insertion:

◦ Anterior surface of greater trochanter

Innervation:

◦ Superior gluteal n

Action

◦ Primary = Hip abduction

◦ Secondary = ER/IR

Tensor fascia latae (TFL) OIAN

Origin:

◦ ASIS

Insertion:

◦ Lateral tibia via iliotibial tract

Innervation:

◦ Superior gluteal n

Action

◦ Primary = Hip abduction, flexion, IR

◦ Secondary = tenses fascia latae

Deep rotators of the hip

Obturator externus

Obturator internus

Piriformis

Superior gemellus

Inferior gemellus

Quadratus femoris

OIANs for deep rotators of the hip

Origin: Posterior sacrum,

ischium, pubis, obturator

foramen

Insertion:

◦ Greater trochanter

Innervation

◦ Sacral plexus

◦ Obturator n

Action

◦ Hip ER

Knee extensors and their OIANs

(All part of quadriceps femoris)

◦ Rectus femoris (anterior hip)

◦ Vastus medialis - Origin linea aspera

◦ Vastus lateralis - Origin linea aspera

◦ Vastus intermedius - Origin anterior femur

All:

I- Tibial tuberosity via patellar tendon

N- Femoral nerve

A- Knee extesion

Knee flexors

Popliteus, plantaris, gastrocnemius

Gastrocnemius OIAN

Origin: Medial and lateral condyles (2 heads)

◦ Insertion: Calcaneal tuberosity

◦ Innervation: Tibial nerve

◦ Action

◦ Primary = ankle plantar flexion

◦ Contributes to knee flexion

Popliteus OIAN

Popliteus

◦ Origin: Lateral condyle of femur

◦ Insertion: Posterior medial tibial condyle

◦ Innervation: Tibial nerve

◦ Action: Initiates knee flexion (reverse screw

home mechanism)

Plantaris OIAN

Origin:

◦ Posterior lateral condyle of femur

Insertion: Calcneal tuberosity

◦ May converge with Achilles tendon

Innervation:

◦ Tibial nerve

Action:

◦ Minor knee flexion

◦ Minor ankle plantar flexion

Spondylolisthesis: what is it and what can happen as a result (name symptoms)?

-Anterior slippage of a superior vertebral body on an inferior vertebral body

-Can result in significant neurological symptoms (ex. cauda equina) THESE INDICATE AN EMERGENCY:

◦ Weakness of bilateral LEs

◦ Changes in bowel/bladder habits

◦ Saddle paresthesia

◦ Sudden difficulty with gait

Term that describes anterior, posterior, or lateral pelvic tilt

Pelvic posturing

Term that describes excessive lumbar lordosis (commonly seen in late stages of pregnancy) or reduced lumbar lordosis

Spinal posture

Condition that results from abnormal lateral spinal curvature

Scoliosis