Kinematics, Joint Structures, Tissue Mechanics PDF

Kinematics & Joint Structures Dr. Rami Said, PT, DPT, MEng www.gfycat.com K&B I – Kinematics & Joint Structures  Kinesiology Functio...

Kinematics & Joint Structures Dr. Rami Said, PT, DPT, MEng www.gfycat.com K&B I – Kinematics & Joint Structures  Kinesiology Functional Gross Applied Anatomy & Anatomy Physiology Biomechanics Kinematics Kinetics Osteokinematics Arthrokinematics K&B I – Kinematics & Joint Structures Kinematics vs. Kinetics Kinematics Kinetics Branch of mechanics that describes Branch of mechanics that describes human movement the effect of forces and torques on the body Kinematic chain Articulated segments of the body, Kinetic Chain connected by joints, that operate Articulated segments of the body, synchronously, so that motion in connected by joints, in which the one segment may influence motion forces or torques that arise in one in another segment, to perform a segment of the body are transferred wide range of human movement to other segments www.gfycat.com K&B I – Kinematics & Joint Structures Human Movement In general, human movement = the translation of a segment’s center of mass powered by the contraction of muscles Regardless of the direction, movement may be active or passive Active = internal force generation (muscle contraction) Passive = external force generation (gravity, another person, tissue resting tension, etc.) Dynamic movement = appreciate both osteokinematics (bone movement) and arthrokinematics (joint surface movement) K&B I – Kinematics & Joint Structures Osteokinematics Describes the motion of bones relative to the cardinal (principal) planes of the body – sagittal, frontal (coronal), and horizontal (transverse) planes – as depicted in the context of the anatomical position Sagittal plane – divides the body into right and left sections Frontal plane – divides the body into front (ventral; anterior) and back (dorsal; posterior) sections Transverse plane – divides the body into upper (cephalad; superior) and lower (caudal; inferior) sections K&B I – Kinematics & Joint Structures Osteokinematics – Axes of Rotation Joint Axis of Rotation (AOR) Point about which movement occurs Bones move around the axis of rotation of a particular joint Planes of movement (cardinal planes) are perpendicular to the axis of rotation Instantaneous Axis of Rotation (IAR) Most joints are not symmetrical or perfectly round, so the axis of rotation often shifts (NOT fixed) with each degree of movement because the relative position between two bones changes K&B I – Kinematics & Joint Structures Osteokinematics Osteokinematic movement is always named for the motion of the distal segment of the joint Examples: Shoulder Abduction = the distal segment (upper arm) is moving away from the body in the frontal plane Elbow Flexion = the anterior surface of the distal segment (forearm) is moving closer to the ventral surface of the upper arm www.gfycat.com K&B I – Kinematics & Joint Structures Osteokinematics – Flexion/Extension Plane of Movement Sagittal Axis of Movement Frontal or Coronal Osteokinematic Joint Movement Flexion = ventral surfaces move closer to one another Extension = dorsal surfaces move closer to one another K&B I – Kinematics & Joint Structures Osteokinematics – Abduction/Adduction Plane of Movement Frontal or Coronal Axis of Movement Sagittal or Anterior-Posterior (AP) Osteokinematic Joint Movement Abduction = distal bone segments move away from midline Adduction = distal bone segments move towards midline K&B I – Kinematics & Joint Structures Osteokinematics – ER/IR Plane of Movement Horizontal or Transverse Axis of Movement Vertical or Longitudinal Osteokinematic Joint Movement Internal (Medial) Rotation = distal bone segment moves parallel to the ground and/or toward the midline External (Lateral) Rotation = distal bone segment moves parallel to the ground and/or away the midline K&B I – Kinematics & Joint Structures Osteokinematics – Exceptions* Some exceptions to the rule: Scapular Motions Upward / Downward Rotation Retraction / Protraction Tilting / Tipping Horizontal Abduction/Adduction = Transverse plane movement Pronation/Supination = Transverse plane movement when arm is by the side K&B I – Kinematics & Joint Structures Osteokinematics – Exceptions* Knee Flexion = Sagittal plane movement with the knee bending (dorsal surfaces move closer to one another) Knee Extension = Sagittal plane movement with knee straightening (ventral surfaces move closer to one another) Dorsiflexion = Sagittal plane movement of the dorsum of the ankle moving closer to the shin Plantarflexion = Sagittal plane movement of the plantar surface of the dorsum moving closer to the floor K&B I – Kinematics & Joint Structures Joint Classifications Structural (Anatomical) Functional (Degrees of Movement) Fibrous Synarthroses – immovable to slightly Cartilaginous moveable Fluid-filled synovium Diarthroses – freely moveable K&B I – Kinematics & Joint Structures Synarthrosis Joints Fibrous or cartilaginous joints that are immovable or slightly moveable and strongly bind bones together or transmits force from bone to bone Fibrous Synarthrosis Joints Cartilaginous Synarthrosis Joints K&B I – Kinematics & Joint Structures Diarthrosis Joints Synovial joints that allow for free movement in uniaxial, biaxial, or triaxial degrees of freedom Always exhibit 7 elements: 1. Articular cartilage – covers surfaces of bones 2. Articular capsule – encapsulates the joint 3. Synovial membrane – internal layer of the capsule that manufacture synovial fluid 4. Synovial fluid – clear, viscous substance that provides friction-free environment for movement and nourishment to the joint 5. Ligaments – protects the joint from excessive movement 6. Blood vessels – provide more nourishment 7. Sensory nerves – sensation of proprioception/pain Comprise the majority of joints in the musculoskeletal system K&B I – Kinematics & Joint Structures Mechanical Joint Analogy Degrees of Joint Types Examples Freedom Hinge Joints Interphalangeal, Humeroulnar Joints Uniaxial Pivot Joints Proximal Radioulnar Joint, Atlanto-Axial Joints Condyloid Joints Metacarpophalangeal, Tibiofemoral Joints Biaxial Saddle Joints Carpometacarpal (Thumb), Sternoclavicular Joints Ellipsoid Joints Radiocarpal Joint Plane Joints Intercarpal, Carpometacarpal (Digits) Joints Triaxial Ball & Socket Joints Glenohumeral, Coxafemoral Joints K&B I – Kinematics & Joint Structures Osteokinematics – Uniaxial Joints Hinge Joint Pivot Joint www.gfycat.com K&B I – Kinematics & Joint Structures Osteokinematics – Biaxial Joints Condyloid Joint Saddle Joint Ellipsoid Joint K&B I – Kinematics & Joint Structures Osteokinematics – Triaxial Joints Plane Joint Ball & Socket Joint www.gfycat.com K&B I – Kinematics & Joint Structures Open vs. Closed Kinematic Chain Open Kinematic Chain (OKC) The distal segment of the chain is NOT FIXED, so motion is UNPREDICTABLE The motion of one segment is INDEPENDENT of the motion of other segments Closed Kinematic Chain (CKC) The distal segment of the chain is FIXED, so motion is PREDICTABLE The motions at each segment are INTERDEPENDENT https://www.healthline.com/health/4-kinetic-chain-exercises K&B I – Kinematics & Joint Structures Arthrokinematics The involuntary, physiologic, accessory, and passive motion between articular joint surfaces that is necessary for normal osteokinematic motion to occur (a.k.a. “joint play”) Dictated by the relationship between the convex and concave articular joint surfaces Functions Improves the congruency of joints Increases surface area of joint surface contact to dissipate force/stress Guides osteokinematic motion https://www.pinterest.co.uk/pin/486036984767809968/ K&B I – Kinematics & Joint Structures Arthrokinematics – Joint Congruency Open-Packed or Loose-Packed Close-Packed Position (CPP) Position (OPP) Maximum congruency of articular Minimal congruency of articular joint surfaces joint surfaces High ligament tension, joint Low ligament tension, joint compression, & bone contact leads compression, & bone contact leads to high joint stability to low joint stability Motion is restricted Motion is promoted Resting position of a joint = maximum loose-packed position Allows the best ability to assess the arthrokinematics of a particular joint K&B I – Kinematics & Joint Structures Arthrokinematics – Type of Motion 3 different directions of movement: 1. Anterior/Posterior 2. Medial/Lateral 3. Superior/Inferior 3 different types of movement: 1. Roll = multiple points along one surface contact multiple points on another articulating surface 2. Glide/Slide = a single point on one surface contacts multiple points on another articulating surface 3. Spin = a single point on one surface rotates on a single point on another articulating surface http://www.kiminstitute.org/ajm K&B I – Kinematics & Joint Structures Arthrokinematics – Convex-Concave Rules When the convex surface moves on a stable concave surface, then the convex surface rolls in the same direction but glides/slides in an opposite direction to the movement of the bone segment When the concave surface moves on a stable convex surface, then the convex surface rolls and glides/slides in the same direction to the movement of the bone segment Rolling always occurs in the same direction of the movement of the bone segment “Convex on Concave” = Roll and Glide/Slide are Opposite “Concave on Convex” = Roll and Glide/Slide are the Same K&B I – Kinematics & Joint Structures K&B I – Kinematics & Joint Structures Tissue Mechanics Dr. Rami Said, PT, DPT, MEng K&B I – Tissue Mechanics Four Types of Tissue Epithelial Tissue Provides a covering (skin, the linings of the various passages inside the body) Nervous Tissue Made up of nerve cells (neurons) that carry "messages" to and from various parts of the body https://www.thinglink.com/scene/786617009851858944 K&B I – Tissue Mechanics Four Types of Tissue Muscle Tissue Includes striated (also called voluntary) muscles that move the skeleton, and smooth muscle, such as the muscles that surround the organs Connective Tissue Supports other tissues and binds them together (bone, blood, and lymph tissues) Many different types that form the basic structure of joints, ligaments, blood, tendon, articular cartilage, capsules, and fibrocartilage https://www.thinglink.com/scene/786617009851858944 K&B I – Tissue Mechanics Connective Tissue Composition Fibrous Proteins Collagen (Types I & II) Elastin Ground Substance (Extracellular Matrix) Glycosaminoglycans (GAGs) Water Cells Fibroblasts Chondrocytes Lymphocytes Adipose Macrophages Leukocytes K&B I – Tissue Mechanics Fibrous Proteins Collagen Most abundant protein in the body Amino acids that are spiraled in a triple helix molecule called tropocollagen Several tropocollagen strands are strongly cross-linked together to make fibrils; Many fibrils make up fibers Various types but Type I & II are the most present https://commons.wikimedia.org/wiki/File:Figure_33_02_06.jpg K&B I – Tissue Mechanics Fibrous Proteins Collagen Type I Thick, strong fibers that elongate very little when stretched High tensile strength makes it ideal for binding and supporting the articulations between bones Found in: ligaments, tendons, menisci, fascia, & fibrous joint capsules Collagen Type II Thinner than Type I  Low tensile strength Provides a framework for maintaining the general shape and consistency of structures Found in: hyaline cartilage, articular cartilage, intervertebral discs https://www.newhope.com/webinars-toolkits-and-downloads/uc-ii-undenatured-type-ii-collagen-joint-health-white-paper K&B I – Tissue Mechanics Fibrous Proteins Elastin Composed of a network of interweaving small fibrils that resist tensile forces yet have more “give” when elongated Able to readily return to their original shape after being elongated/deformed Can be stretched/deformed up to 150% of its original resting length Found in: articular cartilage, spinal ligaments https://www.slideshare.net/ahmedaamer986/barrier-function-biomechanical-properties-of-the-skin K&B I – Tissue Mechanics Ground Substance (ECM) Ground substance Gelatinous material that fills the space between cells, proteins, and fibers that primarily consists of water and glycosaminoglycans (GAGs) GAGs Large polysaccharides that provide resilience to the ground substance GAGs often bind to proteins to form proteoglycans, which provide a diffusion of nutrients to the matrix and an ability to absorb water The action of the proteoglycans and the surrounding fibrous proteins allows the ground substance to be a semi-fluid structure that stabilizes the collagen networks and resists compression Found in: articular cartilage K&B I – Tissue Mechanics Cells Includes Fibroblasts (tendons, ligaments) Chondrocytes (cartilage) Lymphocytes Adipose Macrophages Leukocytes Function Conduct maintenance of synthesizing the specialized ground substance and fibrous proteins unique to the tissue Repair or remodeling of damaged cells Manufacturing of new cells K&B I – Tissue Mechanics Connective Tissue Hierarchy K&B I – Tissue Mechanics Connective Tissue Proper K&B I – Tissue Mechanics Dense Connective Tissue General Characteristics Irregular Few fibroblasts Haphazard orientation of collagen Low to moderate proteoglycans and fibers in the ground substance elastin Well suited to resist tensile forces from Abundance of type I collagen fibers multiple directions Limited blood supply Found in: joint capsule When physically loaded or stressed, Regular able to adapt to external stimuli and Ordered orientation of collagen fibers stimulate increased synthesis of in the ground substance collagen and GAGs Well suited to provide immediate resistance to tension along the length of the tissue Found in: ligaments and tendons K&B I – Tissue Mechanics Regular Dense CT: Tendons Structure Parallel fiber arrangement High % of Type I collagen fibers Low % of proteoglycans and water Function Provide high tensile strength to bear high loads Transmits large tensile forces between active muscle contractions and the bone into which it inserts Creates movement and stabilization to joints K&B I – Tissue Mechanics Regular Dense CT: Ligaments Structure Nearly parallel fiber arrangement Lower % of Type I collagen fibers Higher % of proteoglycans and water Function Provide high tensile strength to bear high loads in primarily one direction but can withstand small tensile loads in other directions too Passive guidance of movement Joint stabilization Sensory proprioception K&B I – Tissue Mechanics Supporting Connective Tissue K&B I – Tissue Mechanics Articular Cartilage Specialized type of hyaline cartilage, made up of chondrocytes and type II collagen fibers, that forms the load- bearing surfaces on the ends of bones (joints) High % of proteoglycans and water allows it to withstand high, repetitive loads Lacks perichondrium, which contains blood vessels and ready supplies of primitive cells to maintain and repair tissue  Mostly avascular and aneural K&B I – Tissue Mechanics Fibrocartilage Mixture of dense connective tissue and articular cartilage Provides resilience, shock absorption, and tensile strength Dense bundles of type I collagen fibers and moderate % of proteoglycans Help support and stabilize joints, guide arthrokinematics, and dissipate/resist tensile, compressive, or shear forces Lacks a perichondrium Found in: intervertebral discs, menisci, labrums K&B I – Tissue Mechanics Bone K&B I – Tissue Mechanics Bone Made up type I collagen fibers, osteoblasts, and a hard ground substance that bind to calcium- and phosphorous-rich minerals Provides rigid support and system of levers for muscles to move the body Thick compact bone surrounds the long shafts of bones while thin cancellous bone encompasses the ends of bones Very little deformation, but remodeling, repair, and regenerations occur often due to its high concentration of blood supply and fibroblastic cells (Wolff ’s Law) High resistance to compressive loads K&B I – Tissue Mechanics Mechanical Properties of Connective Tissue K&B I – Tissue Mechanics Load / Stress Any force that acts on the body can be referred to as load, but the concentration of that load over a particular area is considered stress High loads applied to small areas = high stress High loads applied to large areas = low stress Types of load / stress Tension Compression Bending Shear Torsion Combined loading K&B I – Tissue Mechanics Load / Stress Deformation = when force acts on an object to change its original shape Tensile load  Tension (elongation or stretch) Compressive load  Compression Ability of a tissue to tolerate loads can be graphically depicted in a Stress-Strain or Load- Deformation curve K&B I – Tissue Mechanics Stress / Strain Stress Load over cross-sectional area = F/A (N/m2) Strain % change in length or cross- section in response to load Elongation per unit length of the material in response to load Stress-Strain Curve Toe region Linear/Elastic Region Plastic Region Ultimate Failure Point K&B I – Tissue Mechanics Toe (Non-Linear) Region Very little force is applied The tissue slack (wavy collagen arrangement) is taken up (straightened out) Low strain https://www.researchgate.net/figure/Typical-stress-strain-curve-for-destructive-tensile-testing-of-skeletal-soft-tissues K&B I – Tissue Mechanics Elastic (Linear) Region Greater elongation, as deformation of tissue increases linearly with increasing load (stress) When load is released, tissue returns to original shape Slope of linear region = Young’s Modulus of Elasticity Ratio of stress/strain, indicative of the relative stiffness in a tissue Greater slope = highly stiff tissue (bone) Smaller slope = less stiff tissue (cartilage) https://www.researchgate.net/figure/Typical-stress-strain-curve-for-destructive-tensile-testing-of-skeletal-soft-tissues K&B I – Tissue Mechanics Plastic Region Permanent deformation of tissue When load is released, tissue DOES NOT return to original shape The end of the elastic region transitions to the plastic region at the Yield Point Tissue is elongated beyond its physiologic range Microscopic failure has occurred = permanent deformation (ie, Ligamentous sprain, Tendon/Muscle strain) https://www.researchgate.net/figure/Typical-stress-strain-curve-for-destructive-tensile-testing-of-skeletal-soft-tissues K&B I – Tissue Mechanics Ultimate Failure As elongation continues, tissue reaches its ultimate failure point and loses its ability to hold any tension Point of tissue rupture Most ligaments and tendons will fail at about 8-13% of deformation from their original length https://www.researchgate.net/figure/Typical-stress-strain-curve-for-destructive-tensile-testing-of-skeletal-soft-tissues K&B I – Tissue Mechanics Viscoelasticity Viscous = having an internal resistance to strain when a stress is applied Elastic = ability to return to original shape after stress is removed Viscoelasticity = time-dependent mechanical property of materials that exhibit both viscous and elastic characteristics When subject to a constant load, the viscoelastic properties of human tissues https://slideplayer.com/slide/3815224/ determine their response to loading over a specific period of time  time- dependent strain K&B I – Tissue Mechanics Creep Describes a progressive strain or elongation of a tissue when exposed to a constant load over time Rapid initial deformation followed by a slow (time-dependent) progressively increasing deformation Force remains constant as the strain increases Depending on the tissue, recovery can occur gradually back to the original https://slideplayer.com/slide/3815224/ length, but may also have a permanent deformation K&B I – Tissue Mechanics Stress Relaxation When a tissue experiences a constant strain or deformation over time, the amount of stress that is felt in the tissue decreases over time K&B I – Tissue Mechanics Hysteresis When a viscoelastic material is loaded and unloaded, the unloading curve is different from the loading curve As a tissue is loaded and unloaded, repetitively, some energy is dissipated through the elongation or strain of the tissue and the release of heat With repetitive cycles, more heat is dissipated and more elongation or deformation occurs https://www.physio-pedia.com/Tendon_Biomechanics K&B I – Tissue Mechanics Strain-Rate Sensitivity Viscoelastic tissues behave differently depending on the rate at which a load or stress is applied Rapid Rate of Loading Tissues stiffen quickly, allowing for larger peak loads to be applied before deformation of the tissue can occur (less compliant to elongation) Slow Rate of Loading Tissues stiffen slowly, allowing for smaller peak loads to be applied before deformation of the tissue can occur (more compliant to elongation) Levangie & Norkin, 2011 K&B I – Tissue Mechanics  Biological Factors Affecting Properties of Connective Tissue K&B I – Tissue Mechanics Maturation / Aging During maturation, tensile strength, force generation, force absorption, load to failure, and Young’s modulus of stiffness rates will improve Hormones play a key role in influencing tissue properties Relaxin can reduce tissue stiffness in tendons, ligaments, and cartilage Estrogen can reduce tissue stiffness in tendons and ligaments yet increase collagen content in cartilage and muscle strength With aging, these tissue properties tend to decline, beginning as early as the 3rd/4th decade of life https://www.youngwitness.com.au/story/6047994/mobility-is-great-hypermobility-not-so-much/?cs=24 K&B I – Tissue Mechanics Mobilization / Immobilization Movement promotes remodeling of tissue properties and normal turnover of cells to meet mechanical demands Physical training can increase tensile strength and elasticity of tissues Immobilization will often decrease tensile strength, increase the stiffness of tissues, and adaptively shorten tissue length 8 weeks of immobilization can sometimes take 12 months for recovery of strength and stiffness of tissues K&B I – Tissue Mechanics K&B I – Kinematics & Joint Structures