Download Students create leg-muscle models to learn about muscle structure

L a u re n G o o d w y n a n d S a ra h S a l m
T
eaching the anatomy of the muscle system
to high school students can be challenging.
Students often learn about muscle anatomy
by memorizing information from textbooks
or by observing plastic, inflexible models. Although these
mediums help students learn about muscle placement, the
mediums do not facilitate understanding regarding integration of the skeletal and muscular systems. To make
learning about muscle origins, insertions, and movement
an interactive experience, we created a lab in which
students construct full-size muscle models out of plastic
skeletons, nylon stockings, and various types of tape.
Active participation
Working in groups to construct muscles encourages students to collaborate and actively participate in learning.
Students learn better and remember more when they
are active participants (Springer, Stanne, and Donovan
1999). Edgar Dale proposed a “Cone of Experience” that
categorized different learning techniques based on the
level of student participation (1969).
According to Dale’s model, students who participate
in active-learning exercises, with the greatest student
involvement, remember 70–90% of what they say,
write, or do after two weeks; students who learn with
passive techniques (hearing or reading) only recall
10–30% of the lesson after two weeks (Dale 1969). In
addition, learning is more effective when the teacher
works as a facilitator and students learn with their
peers. “The best answer to the question, ‘What is the
most effective method of teaching?’ is that it depends
on the goal, the student, the content, and the teacher.
But the next best answer is, ‘students teaching other
students’” (McKeachie 1998).
Students create
leg-muscle
models to learn
about muscle
structure and
function
Keywords: Bones and
Muscles
at www.scilinks.org
Enter code: TST120701
December 2007
49
Lab framework
Focus and materials
This lab requires students to construct nine leg muscles
on their skeleton, which is enough to cement the ideas
of origin, insertion, and action (Figure 1). It also teaches
the concepts of antagonistic muscles (muscles that work
in opposition to each other). Although we focused on the
muscles of the leg, there is no reason the activity could not
be extended to other skeletal muscles such as those of the
shoulder and arm.
The muscle-construction activity takes one, two-hour
class period to complete (see clarification on time under
“Background information”). Materials needed include:
one skeleton for each group, nylon stockings, several
types of tape (e.g., masking or painter’s, duct, doublesided, cellophane, electrician’s, and lab tape), and scissors.
(Note: This lab works equally well with full-sized or
small articulated skeletons. Each group of four to six students works with one full-sized skeleton. Smaller group
sizes are preferred when smaller skeletons are used.)
Early in the year, students use skeletons to learn about
bones; reusing these skeletons reinforces the integral relationship between the skeletal and muscular systems. Nylon stockings have the muscle characteristic of elasticity,
are inexpensive, and can be reused. Students use tape to
attach the nylon muscles to the skeletons.
Background information
Several days before the lab, to introduce students to leg
muscle anatomy and terms, we provide students with a
prelab worksheet (Figure 1). Using their textbooks or
other sources, such as the internet, students fill in information on muscle origins, insertions, and actions, and
define terms associated with muscle movement. Doing
research to complete this worksheet ensures students have
the basic vocabulary needed to participate in the lab.
During the lab, students have access to the freely available “Get Body Smart” website (www.getbodysmart.com).
This interactive medium provides details helpful to the
construction of muscle models, such as muscle origin,
Figure 1
Prelab worksheet: Selected leg muscles.
Objective: To study the muscles of the leg by creating
muscles from nylon stockings and tape.
Before coming to lab, use information from your textbook and
the internet to fill out the chart below; bring the chart to lab.
You will be sorted into groups based on the completion of your
chart. (For answer key, see Figure 2.)
Muscles of the leg Origin
Rectus femoris
Sartorius
Gluteus maximus
Biceps femoris, long
head
Semimembranosus
Semitendinosus
Gracilis
Gastrocnemius
Soleus
Insertion
Action
Define each of the following terms associated
with muscle movement:
Flex (Flexion):_____________________________________
Extend (Extension):________________________________
Abduct (Abduction):_______________________________
Adduct (Adduction):_______________________________
Flexion and Extension are antagonistic movements, acting in
opposition to each other. Abduction and adduction also are
antagonistic movements.
50
The Science Teacher
Create the listed muscles by using tape to attach the
nylons to the appropriate origin and insertion on your
group’s skeleton. Use the computer to connect to www.
getbodysmart.com.
Once on the site, click on “Muscular System.” Choose from
the menus related to your muscles. Some muscles are on more
than one menu so check carefully to ensure you have the most
complete information. Click on each muscle in turn to find its
origin and insertion. Note any differences between the website
information and that in your textbook.
At the end of this exercise, you should have a skeleton with
nine nylon muscles.
The lab will be graded as follows:
• Participation: 40%
• Prelab worksheet/Muscles of the leg: 10%
• Writing exercise: 50%
In the form of a letter, upon conclusion of this lab, you will
write a 200-word, two-part review of the lab.
• Part I: Include your opinion of the group work, the
materials that were available, additional materials that
should be available, and the amount of work involved
in creating the muscles. Provide at least two ways to
improve the lab and your favorite part of the lab.
• P art II: Discuss the two tapes your group used and make
a recommendation based on your observations. Do not
name the muscles, their origins, insertions, or actions.
(Provide thoughtful insight.)
Modeling Muscles
insertion, action, and animated movement. On the website, the origin and insertion of each muscle are clearly
described and shown in relation to bone.
Writing exercise
While constructing muscle models, each student group
is also required to test and record the effectiveness of
at least two types of tape. Once the lab is complete,
students write a paper that provides a recommendation
of the most effective tape and an overall review of the
lab (Figure 1) (see “Assessments” later in this article for
more information on this paper).
Lab run-through
On the day of the actual lab, students hand in their prelab worksheets and sit with their lab partners. Each group
has access to a computer and logs on to the Get Body
Smart website. We then give them a brief tutorial on how
to navigate the website. Students are usually proficient
computer users and quickly learn the Get Body Smart interface. (Note: Alternatively, one computer can be shared
by the whole class; other resources, such as textbooks or
lab atlases, can also be used.)
We divide students into groups of four to six, distribute the materials, and discuss the lab in general terms
(the point of the lab, the materials to be used, and a general review of the procedure). Based on the information
learned from completing their prelab worksheets and
the Get Body Smart website, students are directed to use
the nylon stockings and to affix the nylons to the skeleton
with at least two different tapes. Students are reminded
to record details that support which tape is most effective
and why (to be used later in the writing exercise).
Students are given very few instructions in this activity, allowing room for creativity and discovery. For example, students can be given freedom to use additional
materials—in our classes, this has resulted in groups
stuffing the muscles with paper towels to obtain a more
realistic shape. Or, more detailed instructions can be
provided on how muscles should be made, for example
by instructing students to color-code the various muscles
with different colored stockings.
As students work, we circulate and provide input as
needed. Initial problems usually include trouble creating the first muscle and difficulty navigating the website.
Problems with the muscles are often easy to spot and
Figure 2
Answer key to prelab worksheet.
Muscles of the leg
Rectus femoris
Sartorius
Origin
Anterior inferior iliac spine
and ileum
Anterior superior iliac spine
Insertion
Tibial tuberosity
Action
Flexes thigh
Proximal tibia
Abducts, laterally rotates, and
flexes thigh at hip
Gluteus maximus
Dorsal ilium, sacrum, and
Gluteal tuberosity of femur
Laterally rotates, abducts, and
coccyx
extends thigh
Biceps femoris, long head Ischial tuberosity
Lateral condyle of tibia, head of Extends thigh
fibula
Semimembranosus
Ischial tuberosity
Posterior medial condyle of tibia Extends thigh and flexes knee
Semitendinosus
Ischial tuberosity
Proximal medial tibia
Extends thigh at hip, flexes knee,
and medially rotates leg
Gracilis
Inferior pubis
Medial surface of tibia
Adducts, flexes, and medially
rotates thigh
Gastrocnemius
Medial and lateral condyle of Posterior calcaneus
Flexes leg at knee
femur
Soleus
Superior proximal portion of Posterior calcaneus
Plantar flexes foot
tibia and fibula
Define each of the following terms associated with muscle movement:
Flex (Flexion): Decrease the angle at a joint.
Extend (Extension): Increase the angle at a joint.
Abduct (Abduction): To move away from the midline.
Adduct (Adduction): To move toward the midline.
Flexion and extension are antagonistic movements, acting in opposition to each other. Abduction and adduction also are
antagonistic movements.
December 2007
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Modeling Muscles
correct (e.g., a group is incorrectly attaching the gluteus
maximus with a narrow origin or attaching a muscle’s
origin and insertion to the same bone). If the entire class
is having problems forming the first muscle, a teacher-led
discussion or demonstration might be necessary.
In addition to constructing muscles, students experiment with the action and movement of those muscles.
Once the nylon is correctly attached to the skeleton, students can contract the nylon, which mimics the action of
muscle, to clearly see the purpose of a muscle’s design. Students are working with antagonistic muscles and therefore
can have a firsthand experience with this concept.
Once a group has finished constructing their muscles,
we quiz each group member about a different muscle.
Questions include:
• What muscle is this?
• What is the muscle’s action?
• What muscle is it antagonistic to?
• What muscles perform a similar action?
This reinforces learning and ensures all students
have mastered the material. If a student in the group is
having difficulty answering questions, the group is left
to review material from the website and their completed
assignment. If all members of the group demonstrate
competency with the muscles, the group disassembles
their work and moves onto the writing exercise.
If class times are shorter than two hours, two days can
be used to finish the lab. On the first day, the introduction to the lab and the orientation to the Get Body Smart
website can occur; muscle construction can occur during
the second day.
A work in progress.
Students begin to create
the muscles in whatever
order they choose. The
superficial muscle is the
Sartorius and the deeper
muscle is the Rectus
femoris.
Assessment
The lab grade is comprised of three different components:
completion of the prelab worksheet (10%), participation
(40%), and the writing exercise (50%). Participation is
noted for each student as we circulate the room. To encourage participation, if we notice a student not contributing, we ask that student to do something specific, such
as attach the next muscle to its origin.
The writing exercise is comprised of a two-part paper
(Figure 1, p. 50). In the first part, students review the lab,
discuss their likes and dislikes, and provide two suggestions for improvement. In the second part of the paper,
students recommend the most effective tape, providing
reasons for their findings with examples from the lab.
By identifying origins and insertions through research, creating a model by attaching muscles in the
proper locations, and then manipulating the model to
observe muscle movement, students go beyond just rote
memorization—students learn the importance of muscle placement and the connection between structure and
function. As one student put it, “I wrote down all the information about origins and insertions, but I did not really get what it meant until I did the lab.” Although we
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The Science Teacher
have no empirical data showing that this lab increased
student learning, students appear to understand the
material more completely, and we observed real gains in
student engagement. n
Lauren Goodwyn ([email protected]) is an assistant
professor of science and Sarah Salm ([email protected]) is
an associate professor of science, both at Borough of Manhattan
Community College in New York.
References
Dale, E. 1969. Audio-visual methods in teaching. 2nd ed. Orlando, FL:
Holt, Rinehart, and Winston.
McKeachie, W.J. 1998. Teaching tips: Strategies, research, and theory for
college and university teachers. Boston, MA: Houghton-Mifflin.
Springer, L., M.E. Stanne, and S.S. Donovan. 1999. Effects of smallgroup learning on undergraduates in science, mathematics, engineering, and technology: A meta-analysis. Review of Educational
Research 69(1): 21–51.