Introduction to Kinesiology Chapter 1 PDF

Introduction to Kinesiology: Chapter 1 PTH516 Pathokinesiology Letrisha Stallard, DPT Kinesiology and Its Importance to PTs Kinesiology is the study of movement Why is this important...

Introduction to Kinesiology: Chapter 1 PTH516 Pathokinesiology Letrisha Stallard, DPT Kinesiology and Its Importance to PTs Kinesiology is the study of movement Why is this important for PTs? Kinesiology and Its Importance to PTs Kinesiology is the study of movement Importance for PT 1. Rational examination 2. Accurate Diagnosis 3. Appropriate diagnosis KINEMATICS Two types of motion Translation: a linear motion. Can occur in a straight (rectilinear) or curved line (curvilinear) Rotation: movement around a pivot point, or axis Active vs. Passive Movement Active movement caused by stimulated muscles Passive movement caused by forces other than active muscle contractions  Center of Mass (CoM) Standing – anterior to S2 Sitting – anterior to T12 Increased Stability of the Body BoS Base of support CoM Center of mass An object cannot be stable unless it’s Line of Gravity is located within it’s BoS Osteokinematics Sagittal - Flexion/extension Dorsiflexion/Plantarflexion Forward/Backward bending Frontal – abduction/adduction lateral flexion ulnar/radial deviation eversion/inversion Horizontal or Transverse Plane – Internal/external rotation (med/lateral) axial rotation Axis of Rotation The pivot point of all angular movement Pass through the convex bone of the joint Movement at this point is equal to zero (pivot). Degrees of Freedom (DoF) ❖ # of independent directions of movements allowed at a joint ❖ Joints can have up to 3 DoF ie. GH joint 3; wrist 2 (Sagittal and frontal); humeroulnar 1 (sagittal) ❖ Accessory Motion Slight passive translation of joints Test ligaments integrity Hypo/hypermobility Excessive translation may indicate ligamentous injury or abnormal laxity  Quantity of Motion Measuring DoF- range of motion (ROM) Osteokinematic Perspective Elbow flexion  Osteokinematic Perspective Elbow flexion Distal on proximal: Open Chain - Ulna moves on humerus Proximal on distal: Closed Chain - Humerus moves on ulna  Arthrokinematics Roll- Multiple points along one rotating articular surface contact multiple points on another articular surface  Arthrokinematics Slide- (Also known as glide) A single point on one articular surface contacts multiple points on another articular surface  Arthrokinematics Spin A single point on one articular surface rotates on a single point on another articular surface  Roll/Slide Combination Normal roll and slide occur together as a limb moves or pathokinesiological consequences may occur  Roll/Slide/Spin Combination Knee joint provides a good example of this arthrokinematic combination  Arthrokinematic Patterns Ovoid joint Rule, otherwise known as: Convex / Concave Rule Closed- and Loose-Packed Position of Joint Closed-packed position ○ Position of maximal joint congruency and tightness of ligaments and joint capsule ○ Accessory motions are minimal ○ Usually the most stable joint position Loose-packed position ○ Accessory movements are maximal (mid-range usually least congruent position)  Kinetics Branch of study of mechanics that describes the effect of forces on the body. Force – a push or a pull that produces, changes, or stops a movement F= ma  F = ma Given a constant mass, a force is directly proportional to the acceleration of the mass Measuring the force yields the acceleration of the body, and vice versa. A net force is zero when “a” of the mass is zero Forces Affecting the Body  Impact of Forces on the MS System It can be beneficial or detrimental Healthy tissue…able to partially resist changes in their structure and shape Weakened tissue…may not be able to adequately resist a load Stress-Strain Relationship Tension-Stretch Stress-Strain Relationship Creep  Rate of Loading Speed of loading Strain Example: Running Knee cartilage becomes stiffer as rate of compression Internal Forces Produced from structures in body Active Forces- generated by stimulated muscle ○ Largest of internal forces Passive Forces- created by tension of stretched connective tissue, such as: ○ Intramuscular C.T. (connective tissue) ○ Ligaments ○ Joint capsules ○ Nerves, blood vessels, & skin  External Forces Acting from outside the body Gravity pulling on: ○ Mass of body segment ○ External load ○ Physical contact  Force Vectors ❖ Defined: quantity that is completely specified by its magnitude and direction. ❖ Complete biomechanical analysis of a vector includes. 1) Magnitude: Shaft length Arrowhead 2) Spatial Orientation: Shaft S 3) Direction: Arrowhead h a 4) Point of application: Base f t Base  Force Vectors 1. Magnitude: Shaft length ➔ Amount of force ◆ longer line more force ◆ shorter line less force  Force Vectors 2. Spatial Orientation: Shaft of arrow line of force position vertically angled horizontally  Force Vectors 3. Direction: Arrowhead Positive (up or right) Negative (down or left)  Force Vectors 4. Point of application: Base of arrow contacts body part a. Internal (mm. force)-mm. inserts into bone Angle of inclination: angle between tendon and bone b. External: Depends Gravity- COM Physical contact- occurs anywhere Angle affects length of moment arm. Joint Reaction Force Force that exists at a joint Reaction to net effect of IF and EF how internal and external force react to each other Includes ○ Joint surfaces between bones ○ Forces from any if it’s not a periarticular healthy bone or joint, you could structure get more resistance  Musculoskeletal Torques Forces can cause two types of motion: 1. Translation occurs without moment arm- linear a. Distraction or compression b. No rotation mvmt with force through or parallel to axis 2. Rotation- Forces acting at a distance from the joint axis of rotation can cause rotation. a. focus of torque have to have moment arm for rotation Moment (lever) arm: Perpendicular distance between the axis of a joint and force. Torque (moment): Force X Distance of the moment arm -> Force can be internal or external -> The more dominant torque (Internal or external) will determine direction of rotational movement -> Static rotary equilibrium: internal and external forces are equal one isn’t stronger than the other so they stay still Musculoskeletal Torques  Muscle and Joint Interaction Overall effect of a muscle force on a joint Force with moment arm = torque Force without moment arm stabilizing force  Types of Muscle Activation Isometric ○ Constant length ○ External Torque = Internal Torque Concentric ○ Shortening activation ○ External Torque < Internal Torque Eccentric: ○ Lengthening activation ○ External Torque > Internal Torque Determining Action of Muscles without Relying Purely on Memory  Terminology Related to Muscles a) Agonist main muscle doing movement b) Antagonist opposite muscle c) Synergists muscles supplementing movement/ agonist d) Force-couple contracting at same time but doing diff motions e) Reciprocal inhibition f) Co-contraction contracting at the same time g) Passive insufficiency eccentrically stretched and can’t go anymore affect each other. two joint muscle h) Active insufficiency when muscles have been concentrically stretched as far as they can go. (fully clenched) Musculoskeletal Levers  ST 1 Class Lever Axis of rotation is positioned anywhere between the opposing forces Mechanical Advantage (MA) could be less than, equal to, or greater than 1 See-saw o Head and neck Axis external force internal force  nd 2 Class Lever Axis of rotation is at one end Load or external force is between axis and internal force (IF) Internal force possesses greater leverage than the external force (EF), so MA > 1 greater than 1 Rare in human body. o Calf muscles External Force internal force Axis  rd 3 Class Lever Axis at one end and EF at the other end IF located between axis and EF EF has greater leverage less than the IF, so MA < 1 than 1 Most common o Elbow flexor muscles EF IF Axis  Mechanical Advantage IMA/EMA Depends on the type of lever Dictates how work is done by body Short muscular contraction distance ○ Produces a large angular displacement MA of mms less than 1 ○ Greater force required to produce work for IF ○ Large joint forces are generated ○ Fat pads, bursa, cartilage help dissipate these forces Basic Structure and Function of Human Joints Chapter 2 PTH516 Pathokinesiology Letrisha Stallard, DPT Introduction  Joint Classification 1. Synarthroses A. Fibrous Joints B. Cartilaginous Joints 2. Diarthroses Joints  Synarthrodial Joints Fibrous Joints — Stabilized by dense C.T. little to no movement Sutures in skull Teeth (gomphosis) Distal tibiofibular joint Forearm (stabilized by interosseous membrane)  Synarthrodial Joints Cartilaginous Joints little to no movement Stabilized by flexible fibrocartilage and/or hyaline cartilage Diarthroses (Synovial) Joints Most joints of the extremities are synovial No connective tissue directly connects adjacent bony surfaces. Seven elements always: have to have all 7 elements 1. Articular cartilage 2. Articular capsule 3. Synovial membrane 4. Synovial fluid 5. Capsular ligaments 6. Blood vessels 7. Sensory nerves 1. Articular Cartilage Covers ends of bones to protect them 2. Joint (articular) Capsule Composed of 2 layers External or fibrous layer with dense C.T. provides support between the bones and acts to contain joint contents Internal layer = synovial membrane Elbow Joint (anterior view) 3. Synovial membrane Very thin [3-10 cell layers thick] Synoviocytes produce produces synovial fluid ○ Hyaluronic acid (hyaluronate) ○ Lubrican 4. Synovial Fluid Provides nutrition to articular cartilage Provides lubrication ○ Hyaluronic acid (fluid film lubrication) ○ Lubricin (boundary lubrication) Viscosity varies inversely with joint velocity and temperature ○ Importance of warming up 5. Capsular Ligaments External layer of capsule Stabilization of joint Capsular– Resists movement in 2 or 3 planes Extracapsular- Resists movement in 1 or 2 planes 6. Blood Vessels Meager blood supply penetrating only to junction of fibrous capsule and synovial membrane 7. Sensory Nerves Supply pain and proprioception receptors Additional elements for synovial joints Glenoid Labrum Text Meniscus Bursa Articular disc  Mechanical Classification of Synovial Joints See Table 2-1 Hinge Joint Motion occurs perpendicular to the axis of rotation in one plane Interphalangeal Joint Humero-ulnar Joint Pivot Joint Motion of bone occurs in a spin around the axis parallel to axis in one plane Atlanto-axial Joint Proximal Radioulnar Joint Ellipsoid Joint Biplanar motion between convex elongated surface in one dimension of one bone with a similarly elongated concave surface of the paired mate. Flex/ext, abd/add Radiocarpal Joint Ball-and-Socket Joint Motion is in 3 planes (triaxial). Large convex surface of one bone and large concave surface of its mate are cup-like and symmetrical, allowing for spinning motion (unlike ellipsoid joint). Hip Glenohumeral Plane Joint 2 flat surfaces move against each other in up to 2 planes, either by sliding or rotating. Intercarpal Joints Intertarsal Joints Pass out the pringles What do these pringles remind you of? Saddle Joint Motion in 2 planes. The end of each bone is both convex and concave, and at right angles to each other. ABD/ADD – convex MC on concave trapezium FLEX/EXT – concave MC on convex trapezium Thumb CMC Condyloid Joint Motion usually in 2 planes (3rd plane restricted by ligament or bony part). Like ball-and-socket joint except concave member is relatively shallow. Metacarpophalangeal Joint Tibiofemoral Atlanto-occipital Simplified Synovial Joint Classification Planar (flat) joints do not fit this scheme Ovoid Joint Saddle Joint Most joints fit this scheme End of each bone is curved in 2 One member is imperfectly directions, convex and concave spherical and its mate has a Convex surface of one bone changing surface curvature articulates with its mate’s concave One side is convex and other surface concave Oriented ~90 degrees to each other Axis of Rotation an imaginary line extending through a joint around which rotation occurs What member of the joint does it pierce through? Most joints is not fixed ○ Changing axis at any given point in the motion is called the instantaneous axis of rotation ○ Path the instantaneous axis of rotation traverses is the evolute. What are the four primary tissues in the body? There are four primary tissues in the body: 1. Connective Tissue (forms the basic structure of joints) 2. Muscle 3. Nerve 4. Epithelium Histologic Organization of Periarticular C.T. Types of Periarticular C.T. Three types of periarticular connective tissues exist in all joints: dense connective tissues, articular cartilage, and fibrocartilage Dense Connective Tissue Found in external layer of capsule, ligaments, tendons Made mostly of type I collagen (relatively low elastin content) Purpose: ○ Resists tension ○ Protect and bind joint (ligaments) ○ Transfer forces between muscle and bone (tendons) Articular Cartilage (Fig. 2-16) Hyaline cartilage High proportion of type II collagen and proteoglycan content Purpose ○ Distributes and absorbs joint forces (compression and shear) ○ Reduces joint friction Regions of articular cartilage (% thickness) ○ Superficial (10-20%) ○ Middle (40 – 60%) ○ Deep (30 – 40%) ○ Calcified zone – joins deep zone to subchondral bone Tidemark - Edge of calcified zone abutting subchondral bone Fibrocartilage Found in: Menisci (knee) Labra (hip, glenohumeral) Discs (intervertebral, TMJ, sternoclavicular) High proportion of type I collagen Purpose o Supports and mechanically stabilizes joints o Dissipates loads across multiple planes o Guides arthrokinematics guides the way the jt. moves Bone Found throughout body gives structure Made of: ○ Type 1 collagen ○ Calcium deposits ○ Other hard minerals Resists deformation Support and Levers  Factors Affecting C.T Blood Supply if there’s poor blood supply, healing takes a long time to heal or dies Age older people take longer to heal because or poor blood supply Immobilization Muscle: the Primary Stabilizer and Mover of the Skeletal System Chapter 3 PTH516 Pathokinesiology Letrisha Stallard, DPT Introduction Main Purpose of Skeletal Muscle 1. Stabilize bones (postural control) 2. Create movement 3. Provide shock absorption  Muscle as a Skeletal Stabilizer: Force Generation and Length muscle unit fiber Sarcomere (basic unit) - force Non-contractile generator ○ Titin (provides passive tension) Contractile proteins ○ Desmin (stabilizes alignment of sarcomeres) ○ Actin (thin) Myosin (thick)  Extracellular Connective Tissue Epimysium ○ Encloses muscle belly - separates muscles Perimysium ○ Encloses fascicles- blood vessels and nerves travel through Endomysium ○ Encloses muscle fibers Muscle Morphology Fusiform muscles- fibers run parallel Ex. Sartorius, Rectus Abdominis, Rhomboids, Semispinalis Capitis Sternocleidomastoid Unipennate- fibers run obliquely into one side of tendon Penna= feather Ex. Lumbricals 1 & 2 Palmar interossei Flexor pollicis longus  Bipennate fibers run obliquely into both sides two feathers Dorsal Interossei Lumbricals 3 & 4 Multipennate- fibers run obliquely in many directions Serratus anterior Subscapularis Deltoid Gluteus max. Muscle Architecture Physiologic cross-sectional area ❖ Sum= volume/length ❖ Maximal force potential is proportional to sum Thicker muscle generates > F than thinner muscle Muscle Architecture Pennation Angle Greater angle = less force Pennate muscle has greater maximal force than fusiform. (of the same size) Muscle & Tendon: Force Generation Passive Tension ○ Series elastic components – Tendon, Titin (non-contractile)  Muscle & Tendon: Force Generation COMPONENTS 1. Series Slight to moderate stretch– titin Extensive stretch –tendon it’ll start tearing after this point 2. Parallel elastic a. Epimysium b. Perimysium c. Endomysium Passive Length-tension Curve  Muscle & Tendon: Force Generation 1. Slack- muscles initial shortened length 2. Critical length a. Passive tension b. High stiffness c. Rupture Passive Length-tension Curve  Muscle & Tendon: Force Generation Purpose of passive tension 1. Provides necessary tension (active) 2. Assist in movement of joint 3. Dampening mechanism (protects) Passive Length-tension Curve Active Length-Tension Curve Actin filaments slide past myosin filaments – they do not shorten as you contract, the Z disc shorten and get closer together through the actin and myosin myosin bring actin closer and actin ataches to myosin and Z disc to pull them closer  Active Length-Tension Curve Ideal resting length of mm fiber Internal Torque-Joint Angle Curve Physiologic - muscle length changes as joint angle changes Mechanical - moment arm affects leverage available to muscle Note as mm shortens, moment arm increases, so force production is maintained  Muscle as a Skeletal Mover: Force Modulation During concentric & eccentric activations, a very specific relationship exists between a muscle’s maximum force output and its velocity of contraction (or elongation) Neumann p. 59 Max. Muscle Force & Speed of Contraction Concentric – internal torque > external torque Isometric – int. torque = ext. torque Eccentric – external torque > internal torque produce the most force: 1. Eccentric 2. Concentric 3. Isometric  Force-Velocity Curve Maximal-effort concentric activation: Amount of muscle force produced is inversely proportional to the velocity of muscle shortening (slower = ↑, faster = ↓) Maximal contraction velocity ○ occurs: when load is minimal ○ decreases: as load increases Force-Velocity Curve Isometric muscle activation: Contraction velocity =0 Maximum # of attached crossbridges exist within a given sarcomere at any given instant  Force-Velocity Curve Maximal-effort eccentric activation: Amount of muscle force produced (to a point) is directly proportional to the velocity of muscle lengthening (faster = ↑, slower = ↓) Comparing activations Eccentric- greatest muscle force 1. Greater average force per crossbridge 2. Rapid reattachment of crossbridge 3. Viscoelastic properties produces passive tension Eccentric>isometric>concentric  Functional Significance Less effort and more efficient with ECCENTRIC Elongated muscle stores energy for concentric reaction Positive vs. Negative Work Positive with concentric Negative with eccentric Activating Muscle via the Nervous System Motor Unit (MU) Individual muscle fibers innervated by a single alpha motor neuron Smaller MUs – fine control, small force generation Larger MUs – less-refined movements, larger force generation Recruitment When more muscle force is required, recruitment of more MUs activates additional muscle fibers  Recruitment Small MU: recruited first. -Slow oxidative muscle fibers are fatigue resistant Ex. Postural muscles, slow sustained walking. Large MU: large forces -Fast and fatigable -powerful movement