Kinetics of the Knee
LEARNING FOR LIMBS
Kinetics of the Knee Vocabulary
Grade Level: 8 Overview: This lesson integrates the LIMBS prosthe c knee, the 8th Grade Science TEKS in physics (Newton’s laws of Mo on), and the comparison of the human knee joint with a simple machine (lever) that is a review from 7th Grade TEKS.
Lever
Movement
Mo on
Hinge Joint
Big Idea: Force, Mo on, and Energy. Inves ga ng Newton’s three laws of Biomechanics mo on using the human body (knee joint) as our applica on. Kinesiology Human movement is produced by the musculoskeletal system ac ng as a Kine cs system of levers. The physics of a lever system can be directly compared to that of a limb. Physical laws that we learn about in science class – and Force vocabulary such as: force, mo on, momentum, mass, accelera on, balance Resistance and resistance ‐can be applied to mo on of the human body. The knee is one of the most complex joints in the body. It must flex, extend and rotate in addi on to suppor ng the full weight of the body. The knee has only three bones but many muscles, tendons and ligaments that control the movements. The principles of biomechanics, kinesiology, and kine cs all come together in the crea on of a prosthe c limb, like the knee shown in this video. The LIMBS Interna onal M3 knee is a polycentric four‐bar mechanism designed to restore mobility to an amputee, and has the amazing benefit of only cos ng about $30 to manufacture. The use of low‐cost manufacturing techniques means they can be built inexpensively, and help thousands of pa ents in developing countries lead more produc ve lives. In this lesson, students will:
Develop 21st century skills of team work, problem solving and communica on
Make a model of a hinge joint to compare with a knee joint.
Read news ar cle (expository text) from the LIMBS Interna onal Media sec on of the LIMBS Interna onal.org website, and analyze, make inferences and draw conclusions about the text
Create a visual presenta on
Provide evidence from text to support their understanding of expository text
View a video about LIMBS Interna onal
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Students learn that:
Your knee is a similar to a hinge joint in that it primarily bends and straightens in a one direc on
Human movement is produced by the musculoskeletal system ac ng as simple lever machines. The physics of a lever system can be directly compared to that of a limb/joint
Body segments work as a system of levers as they rotate around the joints
A lever is a rigid bar with a point around which it moves when an external force is applied
There are physical laws affec ng mo on ‐ A force is something that tends to change an object’s movement. Simply stated, it is a push or pull exerted on an object
Force causes mo on to change. An object’s mo on changes in response to force. A force has a magnitude and direc on – both are important in determining an object’s mo on
Kinesiology is the study of the body’s infinite number of movements, posi ons, and postures and is grounded in the principles of two (2) sciences: anatomy and mechanics
Mechanics is the study of forces and their effects
Biomechanics is the applica on of mechanical laws to living structures, specifically to the loco motor system of the human body
Biomechanics is mechanics applied to living things
Kine cs is the study of the rela onships between the force system ac ng on a body and the changes it produces in body mo on
Students will be able to:
Understand how the knee joint compares to other joints in the body
Describe the effect of force on the knee joint and how Newton’s laws of mo on affect body movement
Appreciate the work of charitable organiza ons which provide help around the world
Iden fy connec ons between fields of study and professions in the real world
Build a model and analyze how it works
Work in teams to create a presenta on
Math and Science Content Tie‐In: Math ‐ Kinema cs is a branch of the mechanics field of study that deals with the geometry of mo on of objects, includ‐ ing displacement, velocity and accelera on…all of these requiring math calcula ons. Scien sts, mechanics and biome‐ chanical engineers use kinema cs when designing prosthe cs and other medical devices, as well as in the fields of as‐ tronomy, geology and earth science.
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Level(s) of Thinking: Applica on, Analysis, Evalua on, Synthesis
Illustrate and demonstrate
Compare and contrast
Create, design and discuss
Defend and Support
Texas Essen al Knowledge and Skills: Scien fic Process TEKS 1‐4 are interwoven (6) Force, mo on, and energy. The student knows that there is a rela onship between force, mo on, and energy. The student is expected to: (A) demonstrate and calculate how unbalanced forces change the speed or direc on of an object's mo on; (B) differen ate between speed, velocity, and accelera on; and (C) inves gate and describe applica ons of Newton's law of iner a, law of force and accelera on, and law of ac on‐reac on such as in vehicle restraints, sports ac vi es, amusement park rides, Earth's tectonic ac vi es, and rocket launches. Forces and Mo on 1. Understand the fundamental concepts of kine cs and kinema cs. 2. Understand forces and Newton’s Laws. 3. Understand the concept of momentum. §110.20. English Language Arts and Reading, Grade 8 (10) Comprehension of Informa onal Text/Expository Text. Students analyze, make inferences and draw conclusions about expository text and provide evidence from text to support their understanding STAAR Connec on: Grade 8 STAAR Science 2013: Using cri cal thinking, scien fic reasoning, and problem solving to make informed decisions Analyze rela onships among force, mo on and energy Iden fy Newton’s Laws of Mo on Apply Newton’s Laws of Mo on
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Materials:
Copies of the news ar cles from the LIMBS Interna onal Website for groups of students Ar cle tle:
Texas Students Engineer Hope for Amputees – Chronicle of Higher Educa on The Global Village: LIMBS Interna onal is on the Move Group hopes prosthe cs foster independence in Sierra Leone – Dallas Morning News Website www.limbs.org Video from homepage (Time – 3:04) Day 1: Introduc on (Note: This lesson should be used a er, or in‐conjunc on‐with, the unit on Physics and Newton’s Laws of Mo on. Please refer to the 8th Grade Science text for this background informa on. 1. Teacher should read the hand‐outs at the back of the lesson to prepare for class discussions over simple machines, levers, ball‐and‐socket joints, hinge joints, and how the laws of mo on apply to the kine cs of a knee.) 2. Introduce the work of LIMBS Interna onal with the LIMBS promo onal video. go to LIMBS Interna onal website h p://www.limbs.org/ in the media menu select “videos” select “LIMBS Promo onal” Teacher: Ask the students: What is the major component of the LIMBS prosthe c that makes the amputee be able to live a more normal life? Answer: the knee allows for bending and doing more normal ac vi es without sacrificing stability. Other low‐cost prosthe cs o en are unstable or just straight and rigid, which makes it difficult to walk normally or do other labor, recrea on and sports ac vi es. Think of the pirate “peg leg” and how difficult that would make normal ac vi es of walking, running, climbing, carrying a bucket of water, riding a bicycle… Student Ac vity: Have the students get into groups or pairs. Distribute the copies of ar cles for each group tled: Texas Students Engineer Hope for Amputees – Chronicle of Higher Educa on The Global Village: LIMBS Interna onal is on the Move Group hopes prosthe cs foster independence in Sierra Leone – Dallas Morning News Some groups or pairs will get one ar cle, and some will get the others. The groups will then report to the class on their ar cle, and others will need to listen, because they all did not have the same ar cle. Have the students decide on the main idea and important suppor ng details of their ar cle.
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
The students should select a note‐taker and a presenter for sharing their answers. The students will most likely come up with these ideas…
Sustainability of prosthe c program created by LIMBS
Low‐cost prosthe cs created by LIMBS are be er for poor na ons; they cost thousands of dollars in the United States.
More effec ve prosthe cs for difficult and harsh environmental and living condi ons
Knee and foot designs are more durable and be er for the amputees to live more produc ve lives.
Biomedical engineers and college students are working together at universi es to create this new pros‐ the c technology
Have student groups share their answers and discuss these answers with the class. Students should be prepared to defend their answers with support from the ar cles. Teacher may want to write the answers up on the white board. 2. Have students individually reflect and respond on the ar cles and the LIMBS Interna onal video – by wri ng their thoughts on an index card or piece of paper, or in their journal. Prompts for their wri ng: How do you feel about the work LIMBS Interna onal is doing? Which do you feel is the most important aspect of their work, the actual prosthe c, which includes the MI knee, or the crea ng a self‐sustaining ability for developing countries to make their own prosthe cs for low‐cost, which lessens their dependence on foreign aid? Is this an organiza on you might want to help? What charitable organiza ons have you learned about in the past? How does LIMBS compare to other charity organiza ons you have heard of or been involved with? Have some students share their reflec ons.
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Materials: Hinge Joint 2 pieces of wood, 2 inches high by 4 inches wide by 8 inches long Duct tape
Day 2: Introduc on: Teacher: Recap from Day 1 How do the prosthe cs created by LIMBS help the amputees live a more produc ve life? How do the universi es come up with the designs for the prosthe cs?
Biomedical engineers do lots of research studies and trials…
What do these phrases from the LIMBS Interna onal website mean to you?
Sustainable Solu ons for the World
Design, Create, Test and Train
Take some answers and have a quick discussion. Teacher asks: Does anyone know what the term kine cs is? Answer: Kine cs, is the study of the rela onships between the force system ac ng on a body and the changes it produces in body mo on. Teacher says: One of the key components of the LIMBS successful prosthe cs is the durable and technologically advanced knee. Today we are going to study the kine cs of the knee, and how the knee joint acts as an example of a simple machine and relates to Newton’s Laws of Mo on we have been studying. We are going to build two models. One model of a hinge joint and one model of a knee so that we can study the kine cs of the knee. If you were going to create an ar ficial knee, you would need to understand the kine cs of the knee. Teacher walks to a door hinge and asks the students how this hinge is like the knee.
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Student Ac vity: Build a model of the hinge joint and compare it to a knee joint Put the students into groups or lab partners (depending on the amount of supplies the teacher has) Distribute the materials and instruc ons to each group. Each group will build the model. Knee Movement Your knee is similar to a hinge joint, which means that it bends and straightens. Unlike a hinge though, the knee has the ability to rotate slightly as it moves. When you straighten your leg, the quadriceps muscles pull on the quadriceps tendon, which in turn pulls the patella and makes your knee extend. When you bend your leg, the hamstring muscles contact and pull the bia backward toward your thigh, causing the knee to flex. As the knee bends, ligaments work with the muscles and tendons to hold all of the bones together and stabilize the joint. Hinge Joint Instruc ons 1. Place two pieces of wood measuring 2 by 4 by 8 onto a flat surface, end to end. Arrange the pieces of wood so that the 4‐inch sides lie flat. 2. Tape the pieces together on the sides of the wood that are facing upward. Use three to four pieces so that the pieces of wood stay together. 3. Turn the wood upside down so that the underside is exposed. 4. Spread the pieces of wood apart so that the middle is visible. 5. Tape the middle in between the pieces of wood to reinforce it. 6. Hold one of the pieces of wood, allowing the other piece to hang down freely in a 90 degree angle. When you move the hanging piece of wood up and down, it will replicate how a hinge joint moves. A er the students create their model…have them make some observa ons comparing the hinge to the func on of their own knee. Teacher: Distribute copies of the hand‐outs or put them up on the presenta on sta on to go over the informa on on the kine cs of the knee. You may have the students take notes. Relate the informa on on the kine cs of the knee to Newton’s Laws of Mo on You may want to have the students get out their textbooks to review Newton’s Laws of Mo on and determine for themselves how those laws of mo on relate to the knee joint. Which law of mo on applies the best? Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Key points: There are physical laws affec ng mo on ‐ A force is something that tends to change an object’s mo on. Simply stated, it is a push or pull exerted on an object. Force causes mo on to change. An object’s mo on changes in response to force. A force has a size and direc on – both are important in determining an objects mo on Body segments work as a system of levers as they rotate around the joints. A lever is a rigid bar with a fixed point around which it moves when an external force is applied Key terms: mo on, effort, force, resistance Have the students make observa ons about the comparison of the knee and hip joint. Be sure to discuss the chart from the hand‐out on Human Movement that shows Physics and Biology – this clearly demonstrates how it all works! Check out this great resource with discussion ques ons and/or review ques ons provided, and moving diagrams to demonstrate examples. Really cool! (To use with a presenta on sta on.) h p://www.dynamicscience.com.au/tester/ solu ons/hydraulicus/humanbody.htm Student Ac vity: Have the students draw a diagram of the knee joint that demonstrates one aspect of the knee as a hinge joint, as a lever, or how the laws of mo on relate to the kine cs of the knee. This can be to turn in for a grade, to check for un‐ derstanding, or hang around the room.
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Materials:
Cardstock Index cards Art Supplies
Student Journals Paper
Day 3: Introduc on: Teacher asks the students: Does anyone know what the study of mechanics is about? Take some guesses/answers… What about biomechanics? Take some guesses/answers… Can anyone remember what kine cs is from our earlier discussion? What about kinesthe cs, anyone know? Take some guesses/answers… Teacher provides notes/defini ons for the following terms: Kinesiology is the study of the body’s infinite number of movements, posi ons, and postures and is grounded in the principles of two (2) sciences: anatomy and mechanics Mechanics is the study of forces and their effects Biomechanics is the applica on of mechanical laws to living structures, specifically to the locomotor system of the human body Biomechanics is mechanics applied to living things Therefore, biomechanics concerns the interrela ons of the skeleton, muscles, and joints. The bones form the levers, the ligaments surrounding the joints form pivot points, and the muscles provide the forces for moving the levers about the joints Kinema cs is a branch of mechanics that deals with the geometry of the mo on of objects, including displacement, velocity, and accelera on, without taking into account the forces that produce the mo on Kine cs however, is the study of the rela onships between the force system ac ng on a body and the changes it produces in body mo on Knowledge of joint mechanics and structure, as well as the effects that forces produce on the body, has important implica ons for the medical field (sports medicine, medical doctors ‐ knee replacements, crea ng prosthe c devices, like the LIMBS Interna onal MI Knee) Relate Newton’s Laws of Mo on learned to this informa on, and how they have implica ons for any of these fields of study? Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Teacher leads a class discussion: Applica ons of these fields of study: Personal Trainers – Exercise, Workout of muscles More resistance can be created with the same amount of weight by moving the weight farther from the working joint. To lessen the resistance as fa gue occurs, move the weight closer to the working joint. Sports Medicine doctors Overuse and stress injuries can result from the body’s inability to withstand impact and reac on forces.
Overuse and stress injuries can occur in weight training ac vi es which involve momentum: The force of the ssues involved in stopping the mo on must match the mass of the weight and body segment mul plied by the accelera on of the weight and body segment.
Biomechanics (Biomedical engineers)
designing prosthe cs, ar ficial hearts, pace‐makers, running shoes, ski boots
Coaches
designing workouts, assessing fa gue
wrestling moves, mar al arts strategy
Engineers
Manufacturing
Design of new products
Student Ac vity:
1. Have the students get into groups. 2. Give each group a piece of cardstock or poster‐board and necessary art supplies. 3. Have the students get into groups. 4. Give each group a piece of cardstock or poster‐board and necessary art supplies. 5. Have each group design a poster adver sing for universi es ‐ for college students to study biomechanics, kinesiolo‐ gy, mechanics, kinema cs, or kine cs. The poster should include what their professions could be if they study in one of these fields. How will they use their knowledge of one of these fields of study in their professions? Hang the posters around the room or outside in the halls.
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
LEARNING FOR LIMBS
Kinetics of the Knee
Lesson Conclusion: End the mul ‐day lesson with a class discussion on:
Newton’s Laws of Mo on – how they apply to real life!
(May want to assign a math problem u lizing Newton’s Laws of Mo on)
How do we use these laws of mo on in so many different fields of study?
Knee joint ac ng as a lever
LIMBS Interna onal mission and field work, as well as design of prosthe c knee and how it correlates with knowledge of kine cs and biomechanics, how it all relates together!
There are other videos on the LIMBS Interna onal website that provides some more in‐depth knowledge about this prosthe c knee and projects they are doing around the world. Teacher may choose to have students reflect/respond in a journal or complete a wri en reflec on for homework…
Learning for LIMBS Grade 8.7 — Science
© LIMBS Interna onal
