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 51 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 52 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 (lgoodwyn@bmcc.cuny.edu) is an assistant professor of science and Sarah Salm (ssalm@bmcc.cuny.edu) 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.