Muscle Action

Properties of the named muscle

origin

insertion

determination of the joint(s) crossed

Analysis of the joint

axis (axes) of the joint

movement(s) about the axis (axes)

Determination of muscle action

relation of muscle course to joint axis (axes)

implied action(s)

Example

Name:   Tibialis anterior m
Origin:   lateral tibial condyle
upper two-thirds of tibial shaft
interosseous membrane
Insertion:   medial cuneiform:
  medial and inferior surfaces
base of metatarsal I
Joint crossed:   talocrural
Axis of joint:   single,
transverse
Movements:   dorsiflexion/plantar flexion
Joints crossed:   intertarsal
Axes of joints:   no axes per se, gliding joints
Movements:   inversion/eversion
Passage of muscle/tendon:   talocrural joint   anterior
intertarsal joints   lateral to medial
superior to inferior
Action at joint:   talocrural joint   dorsiflexion
intertarsal joints   inversion by elevating and
laterally rotating cuneiform/metatarsal

Muscles for discussion

Muscle Origin(s) Insertion(s)
deltoideus m   clavicle
acromion process
scapular spine 		deltoid tuberosity of humerus
pectoralis major m   clavicle
sternum
costal cartilages 1-7 		crest of greater tubercle of humerus
latissimus dorsi m   spinous processes of T6-T12
spinous processes of L1-L5
sacral spinous processes
posterior portion iliac crest
muscular digitations from ribs 10-12 		lower portion of intertubercular groove of humerus
sartorius m   anterior superior iliac spine proximal medial portion of tibial shaft
gastrocnemius m   lateral head:
  lateral femoral condyle
medial head:
  medial femoral condyle 		posterior aspect of calcaneus

Muscles for self-study

Muscle Origin(s) Insertion(s)
supinator m      
action    
abductor hallucis m      
action    
adductor magnus m      
action    
rectus femoris m      
action    
extensor digitorum longus m      
action    
[ If you want to check your answers for these muscles, please E-mail me ]

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[ Anatomy & Physiology 1 syllabus ]
[ Page created 28 October 1999 ][ Last update 21 June 2004 ]
[ Questions about this lecture? E-mail me ]