The instrument for recording the work done by a muscle or group of muscles is known as:

Question

Accepted Answer

The correct option is (1):
Electromyography, or EMG, is the correct technique and instrument used to evaluate and record the electrical activity generated by skeletal muscles. Whenever a muscle or group of muscles contracts—the fundamental action of doing work—it generates a distinct electrical signal known as an action potential. The Electromyograph instrument uses electrodes inserted into or placed on the skin over the muscle to detect, monitor, and record these biopotentials. By analyzing the characteristics of these recorded electrical waves on a monitor (electromyogram), specialists can assess the muscle's health, its level of activation, and its ability to respond to nerve signals, thus recording the direct functional evidence of the 'work done.'

The incorrect option is (2):
A Stadiometer is a medical instrument designed specifically for measuring human height or stature. It consists of a vertical scale and a sliding horizontal headpiece. Its purpose is for anthropometric measurements, such as calculating Body Mass Index (BMI) or tracking growth, and it has no function whatsoever related to the electrical activity or functional work performed by muscles.

The incorrect option is (3):
A Dynamometer is a device used to measure force, torque, or mechanical power. In physical education and sports science, dynamometers are primarily used to measure the *strength* of a muscle group, such as grip strength, leg strength, or back strength. While strength is a *result* of muscle work, the dynamometer measures the mechanical *output* (force/torque), not the electrical activity or neuro-muscular effort itself, which is what the question implies by "recording the work done."

The incorrect option is (4):
A Manometer is an instrument used primarily for measuring pressure, particularly of fluids or gases. It is commonly used in various scientific and medical applications, for instance, to measure air pressure or blood pressure in a non-skeletal muscle context. It has no practical application in recording the electrical signals or direct work capacity of skeletal muscles.