• how muscles work – in general• muscles that move the mandible• abdominal wall muscles

• anterior and posterior• inferior and superior• inguinal hernia’s

• muscles that move the humerus and scapula• rotator cuff tears, impingement syndrome

• muscles that move the femur• sprains, strains and “Charley horse”

• muscles that move the foot• shin splints, anterior compartment syndrome• Achilles tendon injuries

skeletal cardiac smooth

Tendon

Deep fascia

EpimysiumEpi = upon, above

PerimysiumPeri = around

EndomysiumEndo = within

Connective tissue wrappings of skeletal muscle

Myo, mys = muscle

1 muscle fiber = 1 muscle cellMuscle cells are multinucleated

Working outAtrophy & agingSteroids

Bellies

Insertion

Insertion

Origins Origins

Muscle attachments

Ligaments: bone to boneTendons: muscle to bone

Attachments:• Proximal• Distal

• Direct• Indirect

Aponeurosis

Muscle to skinMuscle to muscle via tendon sheet

Muscle actions:• agonist• antagonist• synergist• fixator

Biceps brachiiBrachialisTriceps brachii

What does this muscle do?

1 2 3 4 5 6

0% 0% 0%0%0%0%

1. Blink2. Smile3. Move your tongue4. Move your neck5. Chew 6. Not sure

X

Mandibular fossa

1. Depress & elevate2. Medial & lateral excursion3. Protraction & retraction

Moving the mandible

Temporalis

Masseter

• attachments• actions

Medial pterygoid

Lateral pterygoid

Muscles that move the mandible

Depress mandible• gravity• digastric muscle• geniohyoid & mylohyoid• when hyoid is fixed

Temporalismassater

Medial pterygoidLateral pterygoid

MylohyoidDigastric

Rectus abdominis

External oblique

Internal oblique

Transversus abdominis

• Attachments• Actions

Muscles that move (and protect) the abdomen/trunk

ABC

D Rectus sheath(aponeurosis)

Linea alba

Abdominal wall• abdominal muscles• back muscles

• quadratus lumborum• Psoas (iliopsoas)

• diaphragm• pelvic diaphragm• “holes” in the wall

• hernia (hiatal) • congenital or acquired

Important postural musclesImportant postural muscles

normalnormal rigidrigid slumped

Spermatic cord

Inguinal canal – men & womenintestines

Parietal peritoneum

scrotum

Inguinal hernia

• attachments• actions (on humerus)

• abduct (lateral fibers)• flex, medially rotate (anterior fibers)• extend, laterally rotate (posterior fibers)

Deltoid

• attachments• actions

• flexion (agonist)• adduction• medial rotation• elevate ribs

Subscapularis• medially rotate

Supraspinatus• abduct

Infraspinatus•Extend•Laterally rotate

Teres minor• adduct• laterally rotate

4 Rotator cuff muscles

Scapula movers & stabilizers

Levator scapulae• elevate scapula• flex neck

Rhomboids• retract• elevate• fix scapula• rotate downward

Trapezius• elevate, rotate upward (S)• retract (M)• depress (I)• extend neck• flex laterally (one trap)

TrapeziusRhomboidsDeltoidTeres majorTricepsLatissimus dorsi

SupraspinatusInfraspinatusTeres minorSubscapularis Levator scapulae

Impingement syndrome

Rotator cuff tears

Hamstring group: flex knee, extend hip

Muscle strains from quick extensions

G. minimus

piriformis

G. Medius

G. Maximus

Gluts: extend, abduct, laterally rotates femurPiriformis: abduct, laterally rotates femur

Iliotibial Band (IT band)

G. MaximusTensor Fasciae Latae• flex femur• abducts femur• medially rotates femur• stabilizes knee

TensorFasciaeLatae (TFL)• flex• abduct• med. rot

Rectus Femoris• flex hip• extend knee Vastus lateralis

vastus intermediusVastus medialis• extend knee

• Charley horse• patella tracking

Patellar tendon

Iliopsoas• flex hip

Adductors• adduct femur• flex hip• flex knee• (lateral rotation)

Lateral rotators• piriformis• obturator externus

Groin pull

IliopsoasTFLSartorius

Adductorsquads Glut max & medius

hamstringsPiriformisSciatic nerve

Achilles tendon

calcaneus

gastrocnemiusAttachments of the gastrocnemiusAttachments of the soleus

Actions of the gastrocnemius1. Flex the knee2. Plantarflex the foot

Actions of the soleus1. Plantarflex the foot

Ruptured Achilles tendonPulled calf muscle

Tibialis anterior

AttachmentsActions

Shin pain:Shin splintsCompartment syndrome

Tibialis Posterior

Intramuscular injection sitesIntramuscular injection sitesDeltoid muscle Vastus lateralis

Gluteal region- right side

Left arm Right leg