Levers and Muscle Action

Transcription

1 3 Levers and Muscle Action Activity developed at Cégep de Sainte-Foy By LUCIE MORIN

2 3 Date Last Tested Author s Name Originating Cegep Author s Address Scientific Discipline Average Age of Students Course Title and Number Duration of Activity 2004 Lucie Morin Cégep de Sainte-Foy lucie.morin@cegep-ste-foy.qc.ca Biology years old Functional Anatomy of the Human Body (101-FYB-04) 2 hours NOTE In this document, the masculine is used without discrimination and solely to make the text easier to read. Appendices are available in PDF and Word format on the CD provided with this document. In addition, an instructional analysis of the activity is available in the pedagogical treasures section (Trésors pédagogiques) on the Saut Quantique Web site at: Use of this text is authorized for instructional purposes, provided that author s name and college are mentioned. Adherence to these recommendations will encourage authors to share their experience.

3 Description of Activity OVERVIEW This activity is aimed at students who are registered in the optional course Functional Anatomy of the Human Body (101-FYB-04) offered during in the fourth (or fifth) term of the Science program. This exercise is done during time scheduled for theoretical courses or laboratory work. Each team of four people must analyze five simple movements to identify various parameters: the joint involved, the muscle chiefly responsible for the movement (agonist) and its anatomical position (point of origin and insertion). Afterwards, it must specify the type of lever and make a schematic drawing of the lever system involved, clearly identifying the fulcrum, load and force (e.g.: elbow, weight of forearm and hand, biceps brachii, etc.). After completing the exercise, the teams are invited to address two problem issues that stimulate their reflective thinking process and the reinvestment of newly acquired learnings. RELEVANCE AND ORIGINALITY OF ACTIVITY This activity helps to illustrate and connect previously studied concepts (bone, joint and muscle functions), and thereby consolidate the knowledge acquired during part of the course. Initially planned only from this perspective, this simple exercise, in terms of material organization and time required, is surprising as to the educational variety it provides. In addition to contributing to the attainment of several program goals, it helps to work on acquiring numerous abilities and attitudes defined in the course guidelines (see Objectives and Relation to the Program for further information). Moreover, this activity is perfectly in line with the pursuit of the general objective of the Functional Anatomy course. The excitement of the class should be felt while the teams make assumptions, exchange thoughts, observe and reproduce the movements they studied, trying to feel which joint is moving, which muscle is working and on which bone it is applying force. Objectives and Relation to the Program PEDAGOGICAL OBJECTIVES OR TARGETED COMPETENCIES Illustrate and connect the following content elements: - Functions of bones (serve as levers for muscle action, determine possible movements); the skeletal system: vocabulary, the bones of the skeleton and their parts; - Functions of joints (provide motion to the skeleton); movements permitted by synovial joints; elbow and knee joints; - Functions of muscles: production of movements; macroscopic anatomy of skeletal muscles; interactions between skeletal muscles; main skeletal muscles. Acquire new content elements and connect them to the previous ones: - Identify and define the three types of levers; discover how they enable certain muscles to work. Work autonomously on reaching the first two objectives, based on acquired learnings and the reference manual. 23

4 Promote reflective thinking and exchanges, and make content learned easier to understand and retain, through active participation. LINK BETWEEN THE ACTIVITY AND THE PROGRAM General Program Goals Targeted This activity targets the following general goals of the Science program: To take a systematic approach to problem solving; To reason logically; To learn autonomously; To apply what has been learned to new situations; To apply the experimental method; To communicate effectively; To work as members of a team. Link with Course The general course objective and associated competency (including competency elements) are as follows: General course objective: The Functional Anatomy course aims at providing solid concepts in human anatomy and histology, while fostering a concrete and overall understanding of the organization of the human body. Statement of the competency: Elements of the competency: To represent various situations, drawing upon relevant concepts, laws and principles of science; To solve problems using a method proper to science; To apply techniques of experimentation or validation specific to science. The activity fosters the attainment of these objectives by taking a more concrete approach to learning anatomy, and encouraging the integration of knowledge. It also helps to develop several skills defined in the course guideline: Use the vocabulary of anatomy adequately; Work in a team; Be independent; Establish the relationships between anatomical structures and their functions; Make schematic drawings of macroscopic anatomical structures; Solve problems involving the structurefunction relationship. Furthermore, this activity introduces muchappreciated variety into a course that basically consists in lectures and laboratory work. Link with Other Courses Studying the physical foundations of muscle action is based on the knowledge acquired during the first physics course, i.e. mechanics. To apply the experimental method in a scientific field, in this case functional anatomy. 24

5 Number of Students and Educational Support APPROXIMATE NUMBER OF STUDENTS IN CLASS 40 students NUMBER OF STUDENTS PER TEAM 4 people EDUCATIONAL SUPPORT The teacher should first make sure that the required content elements are properly defined. He should also take the time to explain the activity and to go over certain concepts or definitions, as required. He explains to the students that in addition to the reference manual, there are other resources available: their own body to visualize and reproduce the movements, their ability to think and make deductions. During the activity, he makes sure that the students are on the right track, i.e. that their work is neither too simple, nor too complex (origin and insertion), and that they use the grid to identify the agonist. He answers the many questions by getting the students to draw from what they already know, and structure their thinking. Finally, based on corrections, he identifies less well-learned concepts and reviews them in class. Conducting the Activity CONDUCTING THE ACTIVITY AND TIME REQUIRED TO COMPLETE EACH STEP Before The teacher makes sure to cover the contents presented in the section Pedagogical Objectives or Targeted Competencies. During Explain the exercise (Appendix S.1): The teacher shows each of the five movements to enable students to properly locate the joint involved. He points out that the analysis will be based on simplified movements, i.e. movements that involve a single joint. If required, he reviews concepts essential to this exercise: point of origin and insertion of a muscle, agonist muscle. (20 minutes) Work on the exercise in teams: At this stage, there are many interactions between the teacher and teams. The teacher answers questions from the students and asks them questions to make sure that they understood the movement properly, correctly identified the agonist muscle involved in the movement, etc. He insists on the importance of completing the grid in the proper order (especially horizontally and not vertically!). (70 minutes) Work on the two questions included at the end of the exercise: The teacher should give preference to questioning, and help students to organize their answers by suggesting that they use the same grid as for the exercise: what is the joint involved, what is the agonist, where are its points of origin and insertion, etc. (20 minutes) 25

6 After The teacher goes over corrections in class. He reviews the exercises and less well-learned items, and discusses reflection questions. Evaluation and Required Material SUGGESTED EVALUATIONS The evaluation of this exercise is more formative than summative: it counts for 1.5% to 2% of the grade for the term. Consequently, the teacher must make corrections effectively. It is suggested to allot one point per square in the grid, except the square Schematic Drawing of System, which will be worth 2 points, for a total of 35 points. No marks are given for assumptions made in answering the two reflection questions. REQUIRED MATERIAL Reference manual specified in the Media Directory. APPENDICES Teacher Other Suggestions and Media Directory OTHER IDEAS TO EXPLORE Since there is little variety in the type of levers seen in the exercise, you could suggest to diversify by adding a second lever of the same type (sitting facing a wall, on a stool with rollers, legs extended, push yourself away from the wall using the tip of the toes), and by introducing a type 2 lever (standing on the tip of your toes like a ballerina). On the students side, the exercise could be extended by asking each team to add a line to the grid: find another body movement and develop the solution for that movement: agonist, type of lever, etc. You could make things more interesting by awarding a bonus (points) to any team who comes up with an example of a type 2 lever, which is a rare occurrence in the body Media Directory Marieb, E.N., Hoehn,K. (2004). Human Anatomy and Physiology, 6 th edition, Benjamin Cummings 1242 pages. Appendix T.1: Solution for the Exercise on Levers and Muscle Action Students Appendix S.1: Exercise on Levers and Muscle Action Note: Appendices are available in PDF and Word format on the CD provided with this document. 26