Featured in PASCO’s Biology through Inquiry Teacher Guide

Biology through Inquiry Teacher Guide

(PS-2870C)

Features 25 inquiry based labs covering the fundamental concepts of cell biology, ecology and physiology.

Muscle Fatigue

Lab Summary

Use a force sensor to determine grip strength and compare muscle fatigue in hand muscles caused by isotonic (“same tension”) and isometric (“same
length”) exercise.

Theory

Students determine their grip strength and compare muscle fatigue in hand muscles caused by isotonic (“same tension”) and isometric (“same length”) exercise. As part of this process, they will do the following:

  • Investigate a loss of force as muscle fatigue develops during a sustained isotonic contraction. Isotonic contractions are produced when heavy objects are lifted.
  • Investigate a loss of force as muscle fatigue develops during a sustained isometric contraction. Isometric contractions occur when a muscle is not allowed to shorten.

Method

Students exercise their hand muscles two different ways, and after each type of muscular contraction, measure the grip force of the hand with a sensor:

  • Measure the change in force exerted when gripping the sensor before and after timed muscular contractions (both isotonic and isometric).
  • Compare the measured forces to determine if muscles become fatigued differently due to the two types of muscular contraction.
  • Compare the measured forces to determine if there is a difference in the way the dominant and non-dominant hands become fatigued.

Sensors / Equipment Used:

PASPORT Force Sensor

(PS-2104)

Designed to measure both pulling and pushing forces. Uses range from collisions to tug-of-war.

Materials Used:

Rubber ball, tennis ball, or equivalent (approximately 7 cm diameter)

Timer (stopwatch or equivalent) 

The Associated Bundle:

Physiology Expansion Sensor Bundle

(PS-2935)

This expansion bundle contains the probeware needed to perform the 5 physiology activities in the Biology through Inquiry lab manual.

Interface Required

This experiment may require software and an interface for data collection.