Learning Mechanics in the Context of Biomechanics Nancy Beverly Mercy College Dobbs Ferry, NY

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1 Learning Mechanics in the Context of Biomechanics Nancy Beverly Mercy College Dobbs Ferry, NY This is part of the Humanizing Physics Project Robert Fuller and Vicki Plano-Clark, University of Nebraska-Lincoln Mark Plano-Clark and Chris Wentworth, Doane College BethAnn Thacker, Texas Tech University The students who predominantly populate the algebra-based introductory physics course are typically preparing for careers in the health or life sciences. These students have needs, interests and attitudes that are considerably different from those of physics/engineering students. The Humanizing Physics project attempts to make explicit connections of physics principles to other sciences, particularly related to human functioning which is innately interesting to all students. The purpose of this approach is not for students to learn biomechanics per say but to learn physics principles and problem solving through biomechanics as a conduit. Engagement of students, necessary for a successful active learning curriculum, is enhanced when the material is perceived as being relevant. Initial Exploration of Concept Body Directed Students own Bodies - Movement/Sensation Students Predict phenomenal behavior - Can student articulate why? Analysis of Concepts with Body Directed Computer Technology Graphical Analysis Mathematical Modeling Use of sensors directed at or on Students own Bodies Increase Scope of Concept Human functioning on different Scales (eg. related to molecular/ cellular functioning) Applications to non-biomechanical Topics

2 Initial Exploration of Concepts Body Directed Students Own Bodies - Students are introduced to concepts through their own body movements and sensations Body-active introduction activities o Commiserate with future applications Techniques for optimizing human motion sports, skill activities Minimizing damage to body tissues Impact or sudden injuries Chronic overuse injuries o Additional sensory input helps incorporation of concepts o Students own bodies are an accessible, non-intimidating (non-technical) piece of equipment o Physics concepts reinforcement possible during daily activities Human Bodies instead of Blocks A) Human as point object - Dot on human cm - passive locomotion, self locomotion B) Human moves object hit, push, throw C) Extended body - Human Body parts limb rotation A) Dynamics of Human CM DOT watch the Dot - how, why does that Dot move? Examples: Not Moving - Force and Torque Equilibrium 1D Equilibrium 2D Equilibrium Torque Equilibrium

3 Passive Locomtion 1D Motion/Forces 1D Motion/2D Forces falling/landing elevator vehicular transport Self Locomotion 1D Motion/Forces 2D Motion/Forces Vertical Jumping Sitting Getting up out of Chair Climbing Stairs Walking Running

4 B) Human moves object - connection between body and object s forces and motion 1D Dynamics 2D Dynamics - Vertical Throwing Aiming Projectile Motion - Horizontal Pushing, Hitting C) Human Body parts - Rotation of Limbs Torque Equilibrium - Muscle forces Rotational Kinematics Torque non-equilibrium Muscle forces Rotational Inertia Angular Momentum Oscillations/Resonance - Arms/Legs in walking

5 C) Models of Body Parts Skeletal parts Students get kinesthetic sense of magnitude of muscle force by pulling on muscle string Components Torque/Torque Equilibrium Torque non-equilibrium Oscillations/Resonance Human Tissue Models Hair, Collagen based gummi worms Hooke s Law, Stress/Strain

6 Analysis of Concepts with Body Directed Computer Technology Body Attached Sensors Rotary Motion Sensors 1D, 2D, 3D Accelerometers Body Directed Sensors Force Platform Motion Sensor Force sensors Sensors attached to skeletal parts Rotary Motion of Limb Force of Muscle Force of Floor/Table, etc. on Extremity Video Analysis Software Sensors allow students to relate bodily sensations to graphical representation. Natural progression to graphical analysis and mathematical modeling of body dynamics Exposure to aspects of real modeling of complex biological systems involving approximations and simplifications Students can predict dominant features of graphs and reconcile measurement results with prediction. Data from students own bodies can be used for individual application New physics for this audience true 2D dynamics 2D motion w/2d forces - walking, running, climbing stairs, getting up out of chair using: 2D &3D accelerometers on students bodies, video analysis - can relate to forces exerted on person during human movement old - ordinarily limited to - 1D motion with 2D forces (eg motion on an incline) or 2D motion with 1D force (projectile motion) Increased emphasis on rotational dynamics Use of rotary motion sensor to monitor limb rotational dynamics Reinforcement of previous translational concepts Connections between of translational and rotational Kinesiology typically does not go beyond static - missing out on dynamic

7 Body Attached Sensors - 2D Linear Dynamics - Rotational Dynamics - Relation between 2D Linear and Rotational Dynamics Rotary Motion on Elbow 2D accelerometer on Hand Rotary Motion on Hip Rotary Motion on Knee Rotary Motion on Hip 2D accelerometer on Foot 2D accelerometer on Foot Walking Lifting forearm/hand up and back down Angular Position vs. time - Centripetal acceleration of hand - Vertical Acceleration vs. time - Angular position of forearm - Horizontal Acceleration vs. time - Angular acceleration of forearm - Angular velocity of forearm

8 Body Directed Sensors - 1D Dynamics Force Plate Force Plate with 1D Accelerometer Vertical Jump - Force of floor vs. time - acceleration of CM Motion Sensor

9 Sensors attached to skeletal parts Rotary Dynamics of Limb Force of Muscle Force of Floor/Table, Bal l, etc. on Extremity Throwing a Ball Rotary Motion on Elbow Force sensor on String/Biceps muscle Jumping Force Sensor underneath ball of foot Force sensor on string/achilles tendon Kicking a Ball Rotary motion on knee Force sensor on string/quadriceps Foot Standing Still - tiptoe Red Force of floor on ball of foot Green Force on Achilles tendon Jumping Purple Force of floor on toe of foot Brown Force on Achilles tendon Throwing Ball - Angular position of forearm - Angular velocity of forearm - Angular acceleration of forearm - Force of Biceps Muscle

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