The elbow is considered a third class lever because the effort is applied closer to the fulcrum than the load.
On a third class lever the power exercised is between the point of support and the resistance.
The elbow is the joint between the arm and forearm, similar to a clamp, performing predominantly flexion and extension movements.
The elbow joint is considered a lever of this type as:
- It has its point of support in the joint itself,
- Resistance is given by the weight of the objects that are lifted by the hand and,
- Between both is the potency generated by the arm and forearm muscles.
In this case, the elbow is characterized because the effort is closer to the fulcrum - the elbow or point of support - than to the load.
- The effort is applied further from the fulcrum than the load and the fulcrum is in the center of the lever correspond to other types of leverage.
- The elbow is used to lift objects, is a general function of the upper limb.