Movement Science and Ergonomics PDF

MOVEMENT SCIENCE AND ERGONOMICS MSAE211 - LECTURE | PRELIMS WEEK 1: MOVEMENT SCIENCE (BIOMECHANICS) Body Movement Combination of linear and rotar...

MOVEMENT SCIENCE AND ERGONOMICS MSAE211 - LECTURE | PRELIMS WEEK 1: MOVEMENT SCIENCE (BIOMECHANICS) Body Movement Combination of linear and rotary. MOVEMENT SCIENCE Ex. Walking The study of how people move in different contexts What other motions do I need to remember? and of the factors related to the analysis, improvement and recovery of physical activity. Focus is on issues encountered in physical activity in Repeated motion everyday life, related to work and free time, as well Same movement pattern that is done many times in as recreational and top-level sports. a given time. ○ Reciprocal Motion ○ Oscillation MECHANICS ○ Pendulum Motion Scientific study and analysis of forces acting on 2. LOCATION matter. Divisions: Anatomical Body Position: standing erect palm 1. Statics. Bodies at rest or in uniform motion. facing forward. 2. Dynamics. Bodies accelerating-decelerating COG of the Body Cardinal Planes ○ Frontal / Coronal BIOMECHANICS ○ Sagittal / Midsagittal ○ Horizontal / Transverse Biology + Mechanics Special Cases Divisions: 1. Kinematics 2. Kinetics Secondary Planes. Plane laid through points aside from the COG. KINEMATICS Hand Center of Sagittal Plane is 3rd Digit Science of the motion of bodies in space. Applies the rectangular coordinate system to Foot describe the body in space. Center of Sagittal Plane is 2nd Toe Wrist DETERMINANTS OF MOTION Abduction is RD Adduction is UD Displacement of a body or one of its segments from one point to another. Ankle Upward movement is DF Variables: Downward movement is PF Type Location Thumb Magnitude Flexion / Extension - Frontal Plane Direction Abduction / Adduction - Sagittal Plane Rate (Rate of change at which the motion occurs) 3. MAGNITUDE OF MOTION 1. TYPES OF MOTION Distance Translatory How far a force moves a body. Linear Displacement / Straight Line In rotary motion, degrees or radians. Rotary Movement of a rigid segment around an axis. MSAE211 Dianela, Alyssa Denise M. BSPT 2-Y1-2 MOVEMENT SCIENCE AND ERGONOMICS MSAE211 - LECTURE | PRELIMS WEEK 1: MOVEMENT SCIENCE (BIOMECHANICS) Goniometry TWO SUBDIVISIONS OF KINEMATICS Application of coordinate system to a joint to measure ROM. In translatory motion, linear distance. Osteokinematics Concerned with movement of bones. 4. DIRECTION Arthrokinematics Concerned with movement of the articular surface. Clockwise, Counterclockwise Flexion, Extension JOINT SURFACES Abduction, Adduction Lateral Flexion Medial (IR) Lateral (ER) 1. OVOID / EGG SHAPE Rotation to R or L ○ (+) sign: rotate to R and up One surface is convex, the other is concave. ○ (-) sign: rotate to L and down Compression, Distraction Convex-Concave Rule The direction of the slide depends upon the moving joint. 5. RATE AND CHANGE OF MOTION Opposite. If the moving joint is convex. Same. If the moving joint is concave. Velocity Rate at which a body or segment moves. m/s, ft/s, deg/s 2. SELLAR / SADDLE Acceleration Have both convex and concave surfaces on each Rate at which a change in velocity occurs. articulating bone. Either (+) or (-) m/s per second; ft/s per second Example CMC Joint of Thumb Elbow Joint DEGREES OF FREEDOM OF MOTION SC Joint Talocrural Joint 1° of Freedom 1 Plane, 1 Axis IP Joint, Elbow Joint THREE TYPES OF MOVEMENTS OF JOINT SURFACES 2° of Freedom Rolling or Rocking 2 Planes, 2 Axes New points contact new points on the other surface. Radiocarpal Joint MCP Joint Sliding / Gliding Same points contact new points on the other surface. 3° of Freedom 3 Planes, 3 Axes Spinning Max. no that a single joint can posses in planar motion Same point contacts the same point on the other surface. GH Joint Acetabulofemoral Joint CLOSED PACKED AND OPEN PACKED POSITIONS Circumduction 2° or 3° of Freedom Closed Packed Position Point of congruency of joint. KINEMATIC CHAIN There’s maximum surface area of contact. Attachments of ligaments are farthest apart and under tension. A combination of several joints uniting successive Capsular structures are taut, the joint is segments. mechanically compressed and difficult to distract. MSAE211 Dianela, Alyssa Denise M. BSPT 2-Y1-2 MOVEMENT SCIENCE AND ERGONOMICS MSAE211 - LECTURE | PRELIMS WEEK 1: MOVEMENT SCIENCE (BIOMECHANICS) Open Packed Position PARTS OF FORCE VECTOR (ARROW) Joint surfaces are incongruent Ligament and capsules are slack and can be distracted. ACCESSORY MOTION / JOINT PLAY → Movement of joint surfaces Tail of Arrow Cannot be performed voluntarily Represents the point of attachment of the F on another body. Essential for N pain free joint function Shaft Frozen Shoulder Line of action of the Force, represents the magnitude of force. Greater tuberosity may strike acromion instead of sliding beneath it. Arrowhead Loss of N joint play (movement) accompanied by Indicated the direction of F pain (joint dysfunction) PRIMARY SOURCES OF F OF MAJOR CONCERN FOR PT JOINT AXES Gravity or weight of body parts or attachments. Not stationary, it moves as position changes Muscles Largest movement is in the knee, elbow and wrist. External Resistance Seldom perpendicular to long axes of bone but are Friction frequently oblique. THREE SECONDARY CONSEQUENCES OF THE PRIMARY KINETICS FORCES Concerned with force producing motion or maintain Joint Compression equilibrium (N) Joint Distraction A branch of dynamics which deals with forces that Pressure on Body Surface correct or modify motion of bodies (B) GENERAL FORCES THEORIES OF MOTION External Forces Aristotle Arise from sources outside the body. Explained the cause of animal and human motion. Gravity At Rest. Natural state ○ Constantly affects all objects Motion. Required a mover ○ Should always be the 1st EF on the human body to be considered. Galileo ○ Pull of the earth on a body (or its Concluded that external force was required to change the segment) velocity of motion but not needed to maintain motion. Wind Water FORCE Other People or Objects A push or a pull that produces displacement. Internal Forces Vector quantities having B magnitude and direction. Arise from sources within the body. Essential to human function. Scalar Quantities Serve to counteract EF that jeopardize the integrity of: Have magnitude only (Ex. 10 Books) - Human Joint Structure - Muscles Vectors - Bones To the R is (+), to the L is (-) MSAE211 Dianela, Alyssa Denise M. BSPT 2-Y1-2 MOVEMENT SCIENCE AND ERGONOMICS MSAE211 - LECTURE | PRELIMS WEEK 1: MOVEMENT SCIENCE (BIOMECHANICS) Friction and Atmospheric PO WEIGHT AND COG ○ Can act both externally and internally to the body. COMPOSITION OF FORCES Resultant Force Combined effect of adding or subtracting two or more forces. The simplest force that can produce the same effects as all the forces acting together. Equal to the sum of individual forces (𝑅 = Σ𝐹) CENTER OF GRAVITY (COG) LEVER The single patient of a body about which every particle of its mass is equally distributed. A rigid bar being acted on by forces that tend to Hypothetical point at which all mass would appear rotate it at its pivot point. to be concentrated. The point at which the force of gravity would appear to act. In adults, slightly anterior to S2 or 55% of height. Slightly higher in males than females Higher in infants and children The sum of the COG of individual segments (Σ𝑟 = 0) Symmetrical Object Located in the geometric center. Asymmetrical Object THREE FORCES OF LEVER Located in the heavier end. Axis or Pivot Location of COG of Individual Segments Weight or Resistance Moving or Holding F ○ Mm. contraction Head In Sphenoid Sinus Wt. Arm Distance from Pivot to Weight Head and Neck On inferior surface of basioccipital bone Force Arm Distance from Pivot F to Axis HAT Anterior to T11 Vertebrae & just below the Xiphoid Process (Its weight is ~ 60% of BW) MECHANICAL ADVANTAGE (MA) Extended UE A measure of the efficiency of the lever. Just above elbow The ratio between the length of FA and the length of WA Arm MA = FA/WA Medial head of Triceps Forearm Pronator Teres insertion Hand Third metacarpal MSAE211 Dianela, Alyssa Denise M. BSPT 2-Y1-2 MOVEMENT SCIENCE AND ERGONOMICS MSAE211 - LECTURE | PRELIMS WEEK 1: MOVEMENT SCIENCE (BIOMECHANICS) Extended LE PRINCIPLES OF DECREASING P° THERAPEUTICALLY Just above knee joint Thigh 1. ↓ Magnitude of F In adductor brevis (or magnus, VM) 2. ↑ Area of Application 3. ↓ Time of Application Leg Below popliteus SPORTS BIOMECHANICS Foot Plantar Ligaments The study of body’s movement during sporting activities. To help athletes improve performance or avoid STABLE, UNABLE AND NEUTRAL EQUILIBRIUM injury. FOUR FACTORS WHERE DEGREE OF STABILITY OR BIOMECHANICAL ANALYSIS MOBILITY DEPENDS Used by professional athletes to ensure they are Height of COG from BOS reaching peak performance. Size of BOS Location of gravity line within BOS Weight of the Body CONCERNS OF PROFESSIONALS Stability Injury Prevention Enhanced by ↓ COG, wide BOS, centered LOG and ↑ weight. Performance Mobility Enhanced by ↑ COG, narrow BOS and ↓ weight. Sport biomechanics may include helping an RELOCATION OF COG amputee find the most effective and efficient prosthetics. Everytime we add an object to the body by wearing Movement within the parameters of a specific it or carrying it, the new COG for the combined body athletic event, such as a boxing match, are studied and external mass will shift towards the additional by sports biomechanics. weight. Sports biomechanics may seek to reduce injuries Ex. Cast to R LE - COG shift down and to R from sports such as sprinting. Holding a suitcase - shift of COG up and to the R Sports biometrics may help a sprinter find small issues that can help improve her speed. BASE OF SUPPORT If small, there’s ↑ demand in NM system If wide, it is advantageous in lifting and carrying PRESSURE Applied force per unit area (P=F/A) and expressed in pounds per square inch (PSI) or kilogram per square centimeter. 1 PSI = 50 mmHg MSAE211 Dianela, Alyssa Denise M. BSPT 2-Y1-2