Read the statements carefully and choose the correct options : Statement: (i) Triceps extension is a III Class Lever. Statement: (ii) Biceps curl is a III Class Lever. Statement: (iii) Standing on the toes is a I Class Lever.

Question

Accepted Answer

The correct option is (4):
This option is correct because only statement (ii) accurately classifies the anatomical lever system. The Biceps curl is universally recognized as a Third Class Lever, which is the most common lever type in the human body. In this action, the elbow joint acts as the Fulcrum (pivot), the contracting Biceps muscle applies the Effort (force) close to the joint, and the hand or external weight acts as the Load (resistance) farthest from the joint. The characteristic arrangement for a Third Class Lever is having the Effort between the Fulcrum and the Load (F-E-L), which prioritizes a high speed and range of motion at the expense of a mechanical force advantage. Since statements (i) and (iii) are biomechanically inaccurate, option (4) is the only correct conclusion.

The incorrect option is (1):
Option (1) is incorrect because it falsely claims that statement (i) is correct along with statement (ii). Statement (i) incorrectly classifies the Triceps extension at the elbow as a Third Class Lever. In reality, the triceps extension functions as a First Class Lever. The First Class Lever is defined by having the Fulcrum positioned between the Effort (triceps insertion) and the Load (forearm/hand). This classic arrangement, like a seesaw (L-F-E or E-F-L), is one of the few examples of a First Class Lever in the human body, not a Third Class.

The incorrect option is (2):
Option (2) is incorrect because it inaccurately includes statement (iii) as correct. While statement (ii) correctly identifies the Biceps curl as a Third Class Lever, statement (iii) is wrong to suggest that Standing on the toes (plantarflexion) is a First Class Lever. Standing on the toes is the most common and classic example of a Second Class Lever in human anatomy. The Second Class Lever configuration involves the Load (body weight) being situated between the Fulcrum (the toes/ball of the foot) and the Effort (calf muscle pulling on the heel). The arrangement is F-L-E, which is characteristic of a Second Class Lever, not a First Class Lever.

The incorrect option is (3):
Option (3) is incorrect because it incorrectly asserts that all three statements are correct. A fundamental understanding of human biomechanics shows that this cannot be the case. As established, only the Biceps curl in statement (ii) is correctly classified as a Third Class Lever. Both the Triceps extension in statement (i) (which is a First Class Lever) and Standing on the toes in statement (iii) (which is a Second Class Lever) are misclassified. Therefore, because two out of the three claims are factually wrong, this option must be rejected.