Download skeletal muscle notes

Terms associated with skeletal
muscles
• Tendon- Attaches
muscle to bone
• Ligament- Attaches
bone to bone
• Origin- The
location where the
muscle is
attached to the
relatively
immovable end of
the bone
Insertion- end of the
muscle that is
attached to the
movable bone
• Prime mover- the
muscle that provides
most of the
movement
• Synergist- muscle
that assists the prime
mover
• Antagonist- the
muscle that opposes
the action of the
prime mover
Axial Muscles
Muscles of the Face
• Frontalis
– Origin: superior
aspect of cranium
– Insertion: skin
around eyebrows
– Action: raises
eyebrows & wrinkles
forehead
Muscles of the Face
• Orbicularis oris
– Origin: maxilla &
mandible
– Insertion: skin
around the lips
– Action: pucker the
lips
Muscles of Mastication
• Temporalis
– Origin: parietal bones
(temporal lines)
– Insertion: mandible
– Action: elevating
mandible
Muscles of Mastication
• Masseter
– Origin: zygomatic
– Insertion: mandible
– Action: elevation of
mandible
Muscles of the Neck
• Sternocleidomastoid
– Origin: sternum &
clavicle
– Insertion: mastoid
process
– Action: abduction &
rotation
Muscles of the Neck
• Platysma
– Origin: clavicle
– Insertion: mandible
– Action: draws
corner of mouth
inferiorly & widens
it.
Muscles of the Torso
• Pectoralis major
– Origin: clavicle &
sternum
– Insertion: humerus
(superior aspect)
– Action: adduction of
humerus, medial
rotation of humerus,
assists in
respiration
Muscles of the Torso
• Pectoralis major
– Origin: clavicle &
sternum
– Insertion: humerus
(superior aspect)
– Action: adduction of
humerus, medial
rotation of humerus,
assists in
respiration & flexion
at shoulder!
Muscles of the Torso
• Rectus abdominis
– Origin: pubis
(superior portion)
– Insertion: costal
cartilage of ribs (57)
– Action: flexes
vertebral column
Muscles of the Torso
• Serratus anterior
– Origin: ribs 1-8
– Insertion: medial
border of scapula
– Action: abducts
scapula, stabilizes
scapula, assists in
respiration.
Muscles of the Back
• Trapezius
– Origin: occipital &
spinous processes
of C7-T12
– Insertion: scapula
– Action: adduct,
elevate & depress
scapula. Extend
neck.
Muscles of the Back
• Latissimus dorsi
– Origin: spinous
processes of T7sacrum
– Insertion: humerus
– Action: extend,
adduct, medially
rotate arm.
Respiration.
Muscles of the Back
• Erector spinae
– Origin: sacrum
– Insertion: cervical &
thoracic vertebrae &
ribs
– Action: extend back
Appendicular Muscles
Muscles of the Shoulder
• Deltoid
– Origin: scapula &
clavicle
– Insertion: humerus
– Action: abduction,
medial rotation, and
flexion of the arm
Muscles of the Shoulder
• Supraspinatus
– Origin: superior of
scapular spine
– Insertion: humerus
– Action: abducts arm
**part of rotator cuff
Muscles of the Shoulder
• Infraspinatus
– Origin: inferior of
scapular spine
– Insertion: humerus
– Action: lateral
rotation of arm
**part of rotator cuff
Muscles of the Shoulder
• Subscapularis
– Origin: anterior
aspect of scapula
– Insertion: humerus
– Action: medial
rotation of arm
**part of rotator cuff
Muscles of Shoulder
• Teres minor
– Origin: lateral border
of scapula
– Insertion: humerus
– Action: lateral
rotation of arm
**part of rotator cuff
Muscles of Rotator Cuff
•
•
•
•
Suprapinatus
Infraspinatus
Subscapularis
Teres minor
**Stabilize
shoulder joint
Muscles of the Arm
• Biceps brachii
– Origin: scapula
– Insertion: radius
– Action: flexion at
elbow, supinates
forearm
Muscles of the Arm
• Triceps brachii
– Origin: scapula
– Insertion: ulna
(olecranon process)
– Action: extension at
the elbow, extension
at the shoulder
Muscles of the Arm
• Pronator teres
– Origin: humerus
(distal) & ulna
(proximal)
– Insertion: radius
– Action: pronation
Muscles of the Arm
• Extensor digitorum
– Origin: humerus
(distal & medial)
– Insertion: distal
phalanges of digits
2-5)
– Action: extention of
hand, wrist, and
fingers
Muscles of the Leg
• Iliopsoas
– Origin: ilium &
lumbar vertebrae
– Insertion: femur
(proximal & medial)
– Action: flexion of hip
Muscles of the Leg
• Gluteus medius &
Gluteus minimus
– Origin: ilium
– Insertion: femur
(proximal & lateral)
– Action: abduction of
hip, rotation of
thigh, hip
stabilization
Muscles of Leg
• Gluteus maximus
– Origin: ilium
(posterior) & sacrum
– Insertion: femur
(posterior)
– Action: extension at
hip, lateral rotation,
abduction at hip
Muscles of the Leg
Muscles of the Leg
• Hamstrings group
– Origin: ischium
– Insertion: tibia
(proximal &
posterior)
– Action: flexion at
the knee, extension
at the hip
Muscles of the Leg
• Rectus femoris
– Origin: ilium
(anterior)
– Insertion:
patella/tibia
(proximal &
anterior)
– Action: hip flexion,
knee extension
Muscles of the Leg
Quadriceps femoris
• Rectus femoris + vastus
group (medialis,
lateralis, and
intermedius)
– Origin: femur (posterior
and anterior)
– Insertion: patella/tibia
– Action: knee extension
Muscles of the Leg
• Adductor group
– Origin: pubis
– Insertion: femur
& tibia
– Action: adduction
of hip
Muscles of the Leg
• Tibialis anterior
– Origin: tibia
– Insertion: medial
and plantar
surfaces of tarsals
& 1st metatarsal
– Action: dorsiflexion
& inversion of foot
Muscles of the Leg
• Gastrocnemius
– Origin: femur
(posterior & distal)
– Insertion: posterior
tarsal (calcaneus)
– Action: flexes knee,
plantarflex foot
Muscles of the Leg
• Soleus
– Origin: tibia & fibula
(posterior)
– Insertion: posterior
tarsals (calcaneus)
– Action:
plantarflexion
Muscles of the Leg
• Soleus is deep to
gastrocnemius
• “Calf” muscle
group
Muscles of the Leg
• Flexor hallucis longus
– Origin: fibula (posterior)
– Insertion: 1st distal phalanx
– Action: flexion of hallux
(big toe)
**very important in “toe off”
Biomechanics of Walking
• Heel strike
– Hip flexed
– Knee extended
– Ankle dorsiflexed
Biomechanics of Walking
• Stance phase
– Hip moves to extension,
although it is neutral
– Knee extended
– Ankle neutral
– Torso balanced over
straight leg
Biomechanics of Walking
• Toe off
– Ankle plantarflexes
– Knee begins to flex
– Hip extends
– Toes extended, and
big toe flexes to
propel forward
Biomechanics of Walking
• Swing phase
– Hip flexes
– Knee flexes
– Ankle dorsiflexes
Biomechanics of Walking