This is the third Investigation of the LabLearner CELL Examining Exercise.

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A. To begin this Investigation, tell students they will continue to perform their exercise program. Ask students to locate their Physical Fitness Log at the end of their Scientist Data Record. Ask students to organize into their exercise pairs.

1. Direct students to follow the same procedure to complete their exercises as during the previous Investigation.

2. Students should first take and record their resting heart rates in the appropriate column before beginning their exercises.

3. Each student should perform their exercise, either the leg lift for each leg for one minute or the jump rope activity for three minutes.

4. After students have completed their exercise, they should immediately take and record their heart rates in the appropriate column of the Physical Fitness Log.

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B. Tell students they may wish to refer to their Scientist’s Glossary during the remainder of the PreLab as they will learn about a third body system that is important in physical fitness, the musculoskeletal (muscles and bones) system.  The following activity and questions are provided to prompt student discussion.

1. Ask students: Which system do you think contains structures that allow you to move? The musculoskeletal system.

2. Ask students: Which functions or structures in the musculoskeletal system are important for movement? Student answers will vary.  The muscles in the body must be able to easily stretch and must be attached to bones in order to produce movement.  Movement occurs at the points where bones intersect.

3. Ask students: Which term describes the location where bones intersect? Joints.

4. Tell students to think about the leg lifts and rope jumping you just performed.  

Ask students: Which joints do you think moved in each activity?  To answer this question, tell students they will perform an activity that will help them think about what joints they engage every time they move. 

Separate the class into groups of three or four cooperative individuals.

a. Tell students to locate Problem 1a in their Student Data Record.  Direct students to circle the joints on the diagram that they used as they performed their exercises and to label which were used when performing the leg lifts and which were used when performing the rope jumping.

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b. Encourage students to think about how they moved while performing the exercise. Based on their analysis, students should use the diagram of the skeleton and work with their group to fill in the first two columns of the table located in Problem 1b in their Student Data Record.

c.   Look at the examples of the different types of joints on this slide (ball and socket, hinge, and pivot).

• Tell students that the joints they used in their exercises fall into these groups.
• Point out that next to each type of joint on the chart, the type of motion it enables is indicated.

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This slide shows examples that are similar to the three bone joint types. Notice for the ball and socket joint, an image of a hip replacement is shown. This engineering marvel has helped countless patients (perhaps students’ grandparents) and clearly shows the ball and socket structure of the hip joint.

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Pivot joint example: Neck

Notice that the head is able to move in nearly every direction.

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Ball and socket joint example: Hip

Notice that the ball and socket joint also has a large range of movements.

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Hinge joint example: Elbow

Notice that the hinge joint has a much-reduced range of movements compared to the ball and socket joint or the pivot joint.

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d. After students have had sufficient time to imagine the three types of joints, encourage them to select one of the joints they circled on their diagram and determine whether they would classify it as a ball and socket, hinge, or pivot.  Tell students it may be helpful to move each joint and observe its type of motion, in order to make their decision.

e. Explain that students’ last task is to describe the range of motion for the joint they listed in their Table.  Encourage students to mimic the movement of the joint they used when performing their exercise.  For example, when discussing the motion of the knee, students could move their knee in the same motion used in the exercise.

f. After student groups have formulated their answers, list their suggestions on the board and discuss each.

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C. Explain that students just finished describing one factor responsible for movements of the body – the unique way in which the bones of the body intersect.

1. Ask students: In order to perform the leg lifts and jump rope activity were any other parts of the body needed? Yes, the muscles.

2. Discuss the terms muscles and tendons with students, emphasizing the physical connection between muscles and bones.

3. Ask students:  How does the musculoskeletal system function to allow movement?  What can I do to increase my muscular and flexibility fitness?  Tell students they should think about these questions as they perform their experiments in the lab.

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D. Use the remainder of the PreLab to prompt students’ reflection on the ongoing training they have been performing and recording in their Physical Fitness Log.

1. Tell students that as part of the data analysis students will conduct when they complete their Physical Fitness Log in Investigation Five, they will create and complete a bar graph to illustrate the effects of their training program on their physical fitness.  In preparation for the analysis, students should begin to construct their bar graph.

2. Ask students to locate the Cardiovascular and Muscular Training Page on the last page of their Student Data Record.  Students may need to refer to the Creation and Completion of a Bar Graph tool from their Procedural Toolbox in order to complete this task.

3. Organize students into comparable groups of three or four students.  Half of the class has been performing leg lifts and half of the class has been performing the rope jumping activity.  Therefore, each group should consist of students who perform the same exercise and will have similar graphs.

4. Instruct student groups to draw the x-axis and the y-axis and determine the scale and labels for each axis.

5. Tell students that because their data may differ slightly among the students in their group, each individual’s beginning and ending points for their scale may vary slightly and, therefore, each student’s scale on the y-axis may vary accordingly, but the basic development of their graphs should be similar.

6. If necessary, assist students in the development of their graphs.  Some students may have difficulty organizing the categories for the x-axis.  In addition, students may not realize that the Pre and PostLab data for Investigations Two through Five can be represented as single categories, with the heart rates reported as averages, because the exercises during the Pre and PostLab were performed for the same time interval.  It may be necessary to help students understand that the data for Investigation One must be kept separate because the time intervals exercised during the Lab and PostLab were different.

7.  After students have completed this part of their bar graph construction, explain that they will graph the data they have and will compile in the Physical Fitness Log at the end of the Investigation and then at the end of the CELL.