Arrangement of muscles at elbow joint:
There are two types of muscles present in elbow joint: -
a) The Bicep Muscle lies in front of the humerus. Its upper end (origin) has two tendons. Its lower end (insertion) has one tendon.
b) The Triceps Muscle lies behind the humerus. Its lower end (insertion) has one tendon. Its origin near shoulder blade has three tendons. Its insertion has one tendon.
Principle of leverage and an elbow joint:
i) Bending of arm may be considered as 3rd type of lever in which effort is between fulcrum and load.
ii) Extension of arm represents 1st kind of lever in which fulcrum lies between load and effort.
Advantage: -
Nearer fulcrum to load make easy to lift the load.
Disadvantage: -
Fulcrum is nearer the effort which is a great disadvantage of these principles.