1. Lesson 20 - Muscle Size and Strength
Objectives
Measure the size and strengths of 3 muscle groups in the arms
Determine whether the size is an indication of their strength
Bellwork
What is the relationship between the size of a muscle and it’s strength?
Getting started:
Rank each muscle group in the arm from 1 – 10
Explain your rankings in your NB

2. Question Hypothesis Materials
Does the size of a muscle indicate its strength?
Hypothesis
If the muscle is ____________ then the strength will be __________ because ___________________
Materials
Bathroom scales, measuring tape

3. Procedure (Monitor technique- no thumbs!)
Inquiry 20.1 p.170 (Demonstrate technique for measuring and discuss answers to step 2)
Use the technique demonstrated to measure the size of a flexed muscle in each muscle group of both arms.
Use the scale to find the strength of each muscle group while flexed in the same position
Repeat steps 1 and 2 for everyone in the group.
Repeat 2-3 times for each person and average
(Monitor technique- no thumbs!)

4. Data/Results Will you convert to Newtons or just use pounds?
Data tables
Table 1 – yourself
Table 2 – your group
Table 3 – Rank your group from smallest to largest for each muscle group
Step 9 - questions

5. Reflections Questions 2-3 p 172 SG Conclusion Next Question
Answer the questions using data. Restate your hypothesis.
Next Question
Reflections
Questions 2-3 p 172 SG

6. Other homework ideas Vocabulary
Extension 2- research what happens when muscles increase in size
Extension 3- test males/females with same sizes
Read “Anabolic Steroids” p 173 SG
Vocabulary
Striated Voluntary
Cardiac Involuntary
Smooth
Force (Newton)