Hướng dẫn đường đi cho cơ thể

Hướng dẫn đường đi cho cơ thể Trước khi bạn có thể đánh giá hoặc điều trị một cơ, trước tiên bạn phải xác định được vị trí của nó. Cuốn sách nổi tiếng này cung cấp thông tin minh họa đẹp mắt cho việc học cách sờ nắn và hệ thống cơ xương. Nó làm cho việc nắm vững các kỹ năng trị liệu bằng tay cần thiết trở nên thú vị, dễ nhớ và dễ dàng. Với 504 trang và 1.400 hình ảnh minh họa bao gồm hơn 162 cơ, 206 xương, 33 dây chằng và 110 cột mốc xương, văn bản này cung cấp một bản đồ vô giá về cơ thể. Ấn bản mới này bao gồm một phụ lục dài 56 trang mô tả các vị trí điểm kích hoạt phổ biến và các kiểu đau của 100 cơ. Trail Guide to the Body là sách giáo khoa được khuyến khích sử dụng cho các bài kiểm tra cấp phép của tiểu bang được quản lý bởi cả Hội đồng Chứng nhận Quốc gia về Mátxa Trị liệu và Chăm sóc Cơ thể (NCBTMB) và Liên đoàn Ban Trị liệu Mátxa Tiểu bang (FSMTB) và là một trong năm cuốn sách duy nhất về danh sách tham khảo kiểm tra chính thức. Ngoài ra, chương trình chứng nhận của Hội đồng cho các huấn luyện viên thể thao ở Hoa Kỳ. sử dụng các hình minh họa về Đường mòn về Cơ thể chất lượng cao của chúng tôi trong các sản phẩm khác nhau của họ, bao gồm cả các bài kiểm tra. Cho dù bạn là một nhà trị liệu xoa bóp, nhà trị liệu vật lý, huấn luyện viên thể thao hay sinh viên theo bất kỳ hình thức tập thể dục nào, Trail Guide to the Body là dành cho bạn

From the author of Trail Guide to the Body Building the Body in Motion Andrew Biel Table of Contents Chapter – Introduction How to Use This Book The Parts List A Day in the Life of Movement Mobility in the 21st Century 12 Chapter – The Essentials of Movement 15 Kinesiology Statics and Dynamics Kinetics and Kinematics Mobility, Stability, Balance and Coordination Simultaneous and Sequential Movement Movement Patterns and Kinetic Chains Proportion, Symmetry and Compensation 16 17 18 18 19 20 21 Chapter – Connective Tissue, part 23 The Ubiquitous Material The Basics of Connective Tissue The Recipe for Connective Tissue Cells Extracellular Matrix In the Lab—A Detour Down the Meat Aisle Soft Tissue Properties Stretch Elasticity Plasticity Creep Thixotropy Tensile Strength Piezoelectric Effect Colloidal Types of Connective Tissue Considering Them Structurally Considering Them Functionally The Push and Pull of Your Tissues Chart—A Connective Tissue Breakdown 24 24 24 25 25 27 28 28 28 28 28 29 29 30 30 31 31 32 33 34 Chapter – Connective Tissue, part 35 Bone Types of Bone Functions of Bone Let’s Build a Bone Structure of Bone Recipe for Building a Bone Major Parts of a Bone 36 36 36 37 37 37 38 In the Lab—Wolff’s Law In the Lab—Stacked and Compressed? Cartilage Fascial Tissues Proper Fascia Fascia Profunda Muscle Envelope Septum Aponeurosis Interosseous Membrane Retinaculum Joint Capsule Ligament and Tendon Other Variations Putting It All Together Bones, Fasciae and All the Rest Functions of Your Connective Tissue Network The Sunflower, Fluid and You In the Lab—Local, Global, Internal and External In the Lab—Collagen, Demand and Flushing 38 39 40 41 42 42 43 43 43 43 43 43 44 45 46 46 46 47 49 50 Chapter – Joints, part 53 Planes and Axes Anatomical Position Planes Axes Movements of the Body Joints in General Joint Classification Joint Structure Let’s Build a Synovial Joint Types of Synovial Joints Joint Function Joint Mobility and Stability Joint Chart 54 54 54 56 57 63 63 63 66 69 71 72 73 Chapter – Joints, part 75 Range of Motion Active and Passive Range of Motion Hypermobility and Hypomobility End-Feel Types of Joint Motion Closed and Open Kinetic Chains Convex-Concave Rule Joint Surface Positions In the Lab—Rejected Bone and Joint Concepts 76 77 79 80 82 85 86 87 88 v Chapter – Muscles, part Basics of Muscle Tissue Types of Muscle Tissue Muscle and Fascia: The True Story Function 101—Contractions Components of Skeletal Muscle Let’s Build a Muscle Build a Sarcomere Thick and Thin Filaments Sliding Filament Mechanism Contraction Cycle Myofibrils and Muscle Fibers Plumbers and Electricians The Wrap-Up Functions of Muscle Tissue Properties of Muscle Tissue 92 92 93 94 96 98 98 99 99 100 101 102 102 103 104 Chapter – Muscles, part 105 Shapes and Arrangements of Muscles Structure Parallel and Pennate A Functional Comparison Two Contests Programming Our Muscle Motor Units All-or-None Spread Out How Much and How Fast? Recruitment Wave Summation Types of Contractile Fibers Three Types Ratios? Types of Contractions Concentric Eccentric Isometric Reverse Actions In the Lab—Tight, Short and Long Muscles vi 91 Chapter 10 – Nerves, part 106 106 107 108 109 110 110 110 111 111 111 112 113 113 114 115 115 115 116 117 119 Chapter – Muscles, part 121 Roles of Muscles No Muscle Is an Island Factors That Affect a Muscle’s Role In the Lab— Passive and Active Insufficiency The Psoas-less Sit-Up Bonus Actions of Muscles Postural and Phasic Muscles X Marks the Spot Length and Speed Matter 122 124 126 Trail Guide to Movement 128 129 129 130 131 133 Nerves and Muscles—The Dynamic Duo Central Nervous System Peripheral Nervous System Let’s Build a Neuron Parts of a Neuron Functions Classifications Synapse Neurons to Nerves The Wrapping Peripheral Nerves Laying Out the Cable Plexi and Nerve Distribution in the Appendages Cervical Plexus Brachial Plexus Axillary Nerve Musculocutaneous Nerve Radial Nerve Median Nerve Ulnar Nerve Lumbar Plexus Sacral Plexus Femoral Nerve Obturator Nerve Sciatic Nerve Tibial Nerve Common Peroneal Nerve Chapter 11 – Nerves, part Let’s Flip the Switch Proprioception and Muscle Function Sensors and Feedback Muscle Spindle Cells Vulnerable The Stretch Reflex Golgi Tendon Organs Lifting a Heavy Box The Bowling Ball Pacinian Corpuscles and Ruffini’s End Organs I Can’t Shorten If You Don’t Lengthen Reciprocal Inhibition and Other Reflexes A Rubber Band Around a Stick In the Lab — Tonus Equilibrium Above All Else Reflexes Putting It Into Practice The Neuromuscular System in Action Proprioceptive (In)Accuracy Levator Goes from to 8.5 Using Muscle Tissue’s Properties 137 138 139 140 141 141 141 141 142 142 142 143 145 145 145 145 146 146 146 147 147 148 148 148 149 149 150 150 151 152 152 153 153 153 154 155 156 156 157 158 158 158 159 160 160 160 161 161 Stretch Reflex versus Styles of Stretching Using the Stretch Reflex to Your Advantage Relax with Your Golgi Tendon Organs Post-Isometric Relaxation and Reciprocal Inhibition In the Lab— The Infant and Lifelong Patterns Fun in a Doorway Chapter 12 – Biomechanics, part Biomechanics—The Basics Statics and Dynamics Osteokinematics and Arthrokinematics Kinetics and Kinematics Force Inertia and Mass Torque Vector Friction Velocity and Momentum Gravity Laws of Motion First—Law of Inertia Second—Law of Acceleration Third—Law of Action-Reaction Force in Depth Linear Force Parallel Force Concurrent Force Torque in Depth Chapter 13 – Biomechanics, part Levers First-Class Lever Second-Class Lever Third-Class Lever In the Lab—Stability In the Lab—Stability, Balance and Motion Chapter 14 – Posture Posture and Gait Two Big Challenges Posture Gait Standing Posture How Do We Get You Upright? 162 163 163 164 165 167 168 168 168 168 169 169 169 170 170 170 171 172 172 173 174 176 176 177 177 178 181 182 183 184 185 186 188 191 192 192 192 193 194 194 In the Lab— Other Postural Points-of-View Healthy Posture The Role of Soft Tissues in Upright Posture Building a Myofascial Core Building Postural Supporters Stability Dysfunction and Pain Patterns Upright Postural Distortions Kyphotic-Lordotic Posture Rounded Back Swayback Scoliosis Torticollis Flat Back Other Common Postural Distortions Forward Head Posture Rounded Shoulders Raised Shoulder Postural Elements in the Lower Limbs Hyperpronation Genu Valgum and Genu Verum In the Lab—Sitting, Bending Over and Lying Down Chapter 15 – Gait Gait Stance and Swing Phases Gait and the Hips In the Lab—Other Factors in Gait Muscle Activity During Gait In the Lab—Furniture and Clothing Abnormal Gaits Muscular Weakness/Paralysis Limitation of Joint Range of Motion Neurological Involvement Taking a Look Around A Day in the Life of Movement, Part Index and More Review Questions and Answers Objectives Joint Range of Motion Chart Glossary of Terms Bibliography Index 196 197 198 200 201 202 202 202 203 203 203 204 205 205 205 205 206 206 207 208 213 214 215 218 219 220 222 226 226 228 229 230 234 239 241 248 249 251 257 259 vii How to Use This Book To Separate or Connect? Trail Guide to Movement is a companion book to Trail Guide to the Body: A hands-on guide to locating muscles, bones and more While Body covers the hands-on subject of palpatory anatomy, this text explores how bones, fasciae, joints, muscles and other structures come together to produce human movement Body puts your hands on the tissues; Movement wraps your mind around the body The intent of this book is to serve as an introduction to the study of human movement for students, practitioners and instructors (FYI: Laypersons might find it interesting, too.) For those who work with the human body, a solid understanding of its structure, function and biomechanics is critical (If you don’t understand how something works, how are you going to change it?) For the same reason you would take your car to a trained mechanic, you would want only a knowledgeable and experienced practitioner to work on your body In order to examine the miraculous acts of movement, balance and stability, we need to go inside the body to explain its parts and pieces Historically, this process has begun with a knife, cutting into the tissue, layer by layer, to the deepest recesses of bone and viscera (images A–C) Over the previous hundred years, this “autopsy approach” has proven valuable to virtually all anatomy and movement texts—including Trail Guide to the Body For our purposes here, however, a different—polar opposite—method will be in order Instead of dissecting the body into smaller, isolated pieces, this book will attempt to build the body into larger, interconnected segments We won’t dig in, we’ll build up (p 3, images 1–5) This concept isn’t just a writer’s whimsy To “start from scratch” and fabricate, assemble and organize the body will give you, the reader, an opportunity to don a construction hat or lab coat and participate in the process You’ll have a stake in how the body functions It won’t just be any body that we’ll be building and analyzing, but your body Your knee, your muscles, your gait (style of walking) As Trail Guide to the Body suggests, you’ll A The typical learning approach would begin with the removal of the skin and supericial fascia B Then the muscles and tendons would be pulled away Return to the Whole As a student of the body, you will find it best to begin your learning journey by dividing the whole into its parts Usually this would begin with the bones, then proceed to the muscles, fascial structures and nerves You would learn how each one is designed and its specific role This makes sense since the body is, after all, tremendously vast and complex Yet, at some point, the parts need to return to the whole Continuing the auto mechanic analogy from above, to understand your car’s structure and function, you would want to take it apart and examine all of its components But to truly comprehend how all of those parts operate to get you down the road, you’d want to put them all back together That is where we’re headed Trail Guide to Movement C And inally the ligaments would be stripped down to the bones need to “roll up your sleeves” and take part in the process— maybe not always with your hands, but certainly with your mind and senses Please note, we’re not going to be constructing all of you For instance, your kidneys and tonsils (as vital as they are) will not be our focus Instead, we’re going to look at the structures and systems chiefly involved with movement Here’s a diferent learning method: Begin with the bones of the arm Strap on ligaments and joint capsules First, we’ll design four key structures essential for movement: (1) connective tissue formations like bone, fascia, tendon and ligament, (2) joints, (3) muscles and (4) nerves We’ll then apply some biomechanical principles before putting your “body” to the ultimate tests of posture and gait (standing and walking) Foremost (as we’ll see on the following couple of pages), we need to draw up a parts list and go on one heck of a shopping spree Attach a variety of muscles and fascial components And insert several long strands of nerves and blood vessels If we’ve constructed it properly, the body part should be highly functional In the case of the forearm and hand, the ultimate test would be to gently grasp an egg without cracking its shell (Oh, well—back to the lab.) Introduction A Day in the Life of Movement The following six pages present some common actions you might perform over the course of a single day Because they are rather mundane, you might have never considered them Yet, they are nothing short of miracles For instance, at this very moment— regardless of what you might be doing or not doing—it’s guaranteed that your mind and body are joining forces to ensure that you so with as much poise and grace as you can muster Whether you are currently lying in bed, putting food in your mouth or safely crossing a waxed floor in slippery, woolen socks, you are deserving of the Nobel Prize in Movement— if they offered such an award This book is not only about you, but also for you It is about you because you have a body capable of performing some or all of the actions seen on these pages You deserve a book of your own You—the homo sapiens who climbs hills, sips lattes, rakes leaves, suffers in pain, stares at computers and scratches his noggin wondering what this life is all about It is for you because chances are you’re a student, instructor or practitioner who would like to gain greater insight into human mobility and its relationship to your work with your clients A big stretch to start the day Pulling on pants It begins with a stretch and ends with a yawn The brushing of teeth, the chewing of toast, the guzzling of juice, the panting of the morning jog The carrying of books, the walking up stairs The collapse of the gluteals into chairs, the assuming of postures and the developing of pain in the low back The tying of laces, the leaping of hurdles, the giving of massages The pulling of ropes, the lifting of boxes, the twisting of torsos The rubbing of eyes, the slipping on of PJs, the snuggling of pillows The snores of mouths, the twitches of legs and the dreams of minds It is a day in the life of movement Yes, holding a toothbrush happens at the hand, but it all starts way up in the shoulder at the scapulothoracic joint Catching up with a friend as you walk to class A brush of the teeth Have you ever wondered how you were meant to move, stand or walk? A good place to answer that question is in front of a mirror Hopefully, you’ll observe two arms and two legs connecting to a central torso A head will be on top You weren’t designed with three arms or one leg Nor with three legs and a head coming out from the side Your design evolved over millennia for one express purpose—to move Symmetrical, bipedal and upright Sure, digestion and the other bodily functions are critical, but a strong case could be made that they all serve one larger purpose: to get you from here to there Trail Guide to Movement The Essentials of Movement Kinetics and Kinematics Kinetics studies forces (such as gravity, friction and pressure) that act on the body to generate or alter motion Kinematics involves the analysis of movement in terms of mechanical elements (such as time and space) From a kinetics perspective, slipping on a banana peel (2.5) would encompass how little friction there is between the peel and the floor and how gravity laid you out Kinematics, on the other hand, would be concerned with how fast you were walking when you slipped and how far your center of gravity fell Neither would address whether or not you’re absentminded We’ll discuss these concepts further on page 168 2.5 Whoops! Looking for some inexpensive kinesiological analysis of contorted postures? With ten bucks and a handful of classmates, nothing beats a game of Twister Mobility, Stability, Balance and Coordination 2.6 Stability in action 18 Trail Guide to Movement In the “dance troupe” of human movement, there are four “prima ballerinas”—mobility, stability, balance and coordination The choreographed participation of all four is required for virtually all of your daily actions Mobility, the ability to move, is the obvious and expressive aspect of motion, and receives much attention Often unseen and far less considered, however, is its silent partner, stability Whether you’re jumping hurdles or standing perfectly still, the ability to be firmly fixed or supported is always working in the background Using an ever-changing contingent of joints and myofascial units (muscles and fascial elements), stability generates the necessary—and sometimes oppositional—support for mobility If you’d like to give stability a moment in the spotlight, just play Twister, where it will be front and center, holding you in place on the mat (2.6) Before you commence your next awkward move, stability is already on the scene (“stability before mobility”), anticipating which structures will need reinforcement so you don’t crumble into a pile of arms and legs kinetics kinematics ki-neh-tics ki-neh-mat-ics Types of Connective Tissue CONNECTIVE TISSUE Considering Them Functionally 3.21 Propping up the body from below 3.23 Willis Tower (a.k.a Sears Tower), built on compression 3.25 A stool—compression with a bit of tension 32 Trail Guide to Movement The previous page divided up connective tissue types based on structure Now let’s look at them in terms of their function First of all, each type of connective tissue performs a range of purposes Bones serve as levers and ligaments support joints, while other tissues transport nutrients, defend against disease, repair tissue, store energy, and protect and insulate internal organs But for our purposes here (the understanding of human mobility), connective tissues can be functionally divided into two groups—compression tissues and tension tissues Before we discuss these two groups, we need to first pose a simple, yet crucial, question If your body is to swing bones, hoist limbs, bend over and more, how shall it be supported? An initial, wild guess might involve poles from below or puppet strings from above (3.21, 3.22) It turns out that as crazy as these two ideas sound, they aren’t far off We’ll just need to incorporate both concepts and build them inside the body (No small order.) The reason these “stick and string” ideas aren’t so far-fetched is that there are only two ways to hold up a structure (at least in this universe)—with compressive or tensile forces In other words, propped or suspended For example, skyscrapers are propped, mobiles are suspended (3.23, 3.24) Everything around you—a chair, plant, teacup, house, trampoline or your body—is based on one of these designs, with all structures using both forces as the need arises For instance, sit on a stool—a classic “propped” device—and sense how it primarily uses compression as a force to support your weight The top and bottom of each leg squeeze together while lesser tensile forces expand each leg’s girth (3.25) In contrast, lie in a hammock—a quintessential suspended structure—and feel how it principally uses tension as a force to support your body Its ropes stretch apart while other compressive energy pushes together the cords’ fibers, making them thinner (3.26) This dynamic dance between both compression and tension can be easily felt on a third resting option, a FitBall The top and bottom compress together, while the sides bulge apart with tension (3.27) Now let’s look at what all of this has with your connective tissues 3.22 Hanging it from above 3.24 A mobile is held together with tension v 3.26 A hammock— tension with a bit of compression 3.27 A FitBall—an equal combination of both compression and tension Fascial Tissues In a few chapters we’ll see how muscle fibers serve as the engines of contraction and mobility That being the case, you might wonder, “What is facial tissues’ role in movement?” An analogy might help: Just as a car will sit idle without a drive shaft, belt and motor oil, muscle tissue is crippled without the organization, transference of energy and lubrication provided by fascial tissues (4.13) One is useless without the other We’ll divide these structures into three groups—(1) the sheets (proper fascia), (2) the cables (tendon and ligament) and (3) the other variations (such as superficial fascia and periosteum) CONNECTIVE TISSUE Now that we’ve constructed the compression structures of bone and cartilage, let’s move to their connective tissue comrades that generate tension Fascial tissues are the body’s sheets, cables, conduits and padding and are composed of loose or dense connective tissue (page 31) They include tendons, ligaments, superficial fasciae and the tissues that envelop muscle bellies Unlike bones and cartilage, which will provide compressional strength to your body, these structures will use their fastening attributes to form a body-wide network of tension They’ll not only bind structures together, but also allow tissues to slide smoothly over each other Fasciculi (bundles of fascicles) One Single Mass of Tissue { Epimysium Historically ignored, fascia has only recently found some well-deserved respect for its role in mobility and postural integrity There is even a semiannual Fascia Research Congress to discuss the stuff (Yes, they have such meetings, and you can even attend.) Latin for band, bandage or strap, fascia has been defined as the “soft tissue component of the connective tissue system that permeates the human body.” Yet its very nature confounds attempts to define it As helpful as it might be to isolate and describe these tissues, the fact is that they’re separate in name only Attend a cadaver class (highly recommended, by the way) and you’ll see and feel how they truly represent one single mass of tissue As we build and explore further, please keep in mind that “fascial tissues” is really just “tissue”—singular Fascia profunda Shaft of femur (coated in periosteum) Quadriceps femoris group Epimysium Superficial fascia and adipose Skin 4.13 Anterior view, fascial layerings of the left thigh Connective Tissue—Part 41 Movements of the Body Ribs/Thorax JOINTS The arrows indicate the motion of the ribs When inhaling, your ribs elevate (left); they depress (right) when you exhale Elevation/expansion (inhalation) Depression/collapse (exhalation) Scapula (scapulothoracic joint) Adduction (retraction) Elevation Abduction (protraction) Depression Scapular ROM at acromioclavicular joint Upward rotation 30˚ Downward rotation 0˚ Scapular ROM at sternoclavicular joint Upward rotation Downward rotation 58 Trail Guide to Movement 60˚ 0˚ Upward rotation of left scapula Downward rotation of right scapula Let’s Build a Muscle As we saw on the previous page, a muscle is a highly organized organ that can be broken down into smaller and smaller subsections • A muscle belly is comprised of chunky fascicles, which are formed by tubular muscle fibers (cells) • These cells are made of smaller tubes, myofibrils, which are composed of thread-like myofilaments Myofibrils are divided into a series of sections— sarcomeres—each containing many pairs of myofilaments On page 93 we quickly assembled a brachialis Now let’s build one with much more attention to detail To so, we need to begin with a single sarcomere • 7.18 Your muscle belly won’t contract like an accordian 7.19 but it will shorten like a telescope Build a Sarcomere A sarcomere contains an arrangement A sarcomere in a muscle is like an of thick and thin myofilaments (7.20) individual drop of water in a river It’s Amazingly, the ratcheting action that the basis of it all The infinitesimal occurs between these fragile fibers is the shortening of a sarcomere (along with foundation of your big, strong muscles its many thousand or million comrades) To form these filaments, we’ll need five is what ultimately produces a full7.20 Myoibril comprised of sarcomeres different protein molecules—myosin, actin, blown muscle contraction tropomyosin, troponin and titin To build a barrel-shaped sarcomere, A myosin molecule resembles a pair of coiled snakes we’ll need to create a mechanism that does not operate like with their heads sticking out (7.21) We’ll need 300 or so of the folding action of an accordian (which is how muscle these serpents to form a single, thick filament (7.22) While contraction was conceptualized long ago, 7.18), but more as the snake bodies form the filament’s shaft, the snake heads a retractable telescope, with components that slide past each (myosin heads) will branch off the sides of the filament other (7.19) For this, we’ll need some threadlike filaments Thick filament 7.21 A single myosin molecule 7.22 Bundling myosin molecules to form a thick ilament Steps 1–4 start here 98 Trail Guide to Movement fascicle myofibril fas-i-kl my-o-fi-brel myofilament myosin my-o-fil-a-ment my-o-sin Types of Contractions Isometric Finally, bring the object back up halfway and stop Now your biceps brachii, working against the resistance of gravity, tenses in place and produces an isometric (“equal length”) contraction (8.28) Unlike the concentric and eccentric variations, there is no joint movement here This type of contraction also occurs when oppositional muscles engage simultaneously For instance, when examining your impressive “guns” in the mirror, your elbow joint remains fixed as your biceps and triceps brachii both contract isometrically against each other (8.29) MUSCLES 8.28 Holding the little guy steady with an isometric contraction With these three contraction types at our disposal, we can create, control or prevent joint motion—in other words, mobility and stability In general, concentric contractions will be used for acceleration movements (seen in the anterior deltoid when throwing a baseball), while eccentric contractions will occur during deceleration activities (seen in the infraspinatus immediately following the release of the ball) To resist undesired joint motion, we’ll use isometric contractions Their ability to stabilize is evident when you stand upright and don’t fall facedown in the dirt, thanks to the supportive efforts of postural muscles like erector spinae and hamstrings 8.29 The “gun show” in the mirror demonstrates isometric contractions Contractions and Gravity Let’s take a moment to consider the relationship between these types of contractions and the mother of all forces—gravity Your concentric and eccentric contractions can occur against, with or neutral to gravity For example, when lying supine in bed (1), both of your sternocleidomastoids (SCMs) concentrically engage and work against gravity to flex your neck (2, 3) To lower your head back down, they eccentrically contract and move the head with the pull of gravity Now sit on the edge of the bed and look over your right shoulder (right) Your left SCM rotates your neck and moves your head horizontally relative to gravity, or neutrally to its force (See page 171 for more info on gravity.) 116 Trail Guide to Movement Biomechanics—The Basics Now that you have a body capable of movement—with fasciae, bones, muscles and more—it might be helpful to recognize that all of your actions require some basic physics That is to say, we need to explore the biomechanics of movement At this point, you might be excused for slamming shut this book (or tablet) After all, joints and nerves are one thing, but physics? Yet, before you rush out the door, please remember that biomechanics, the mechanical principles that directly relate to the body, is just another way of talking about everyday stuff Washing your hands? Friction Trying to open a pickle jar? Torque Beelining across a dance floor to meet that special guy or girl? Vector Even lifting bags of concrete (Newton’s Second Law of Motion) or raising a water bottle to your mouth after all of that heaving (third-class lever) is biomechanics in action Whether you are in motion or at rest, these principles will illuminate your ordinary actions So let’s keep it fun and simple, and explore how these laws of motion, levers and forces relate to mobility and stability in your life and bodywork practice First, we’ll look at some of the major concepts Then we’ll “get behind the eyeball” of Sir Isaac Newton* to understand his three laws of motion We’ll finish our exploration with force, torque, levers and stability Statics and Dynamics 12.1 Joe P on his machine As we discussed in more depth on page 17, statics deals with aspects of nonmoving (or virtually nonmoving) systems Joseph Pilates, shown here holding a position on his Reformer, provides a good example of the “dynamic tension” that statics can often involve (12.1) Dynamics applies to aspects of moving systems It focuses on your “dynamic body”—one that changes shape at an appreciable rate—and how various forces affect it Dancing and playing the flute in the middle of the street (as you do) is one way to show off your energetic capacity (12.2) Dynamics can be broken into kinetics and kinematics (see below) 12.2 We’re not making this up BIOMECHANICS Osteokinematics and Arthrokinematics Kinetics and Kinematics On page 82, we examined in depth two types of joint movement Osteokinematics concerns the pathways of moving bones Arthrokinematics, the less-considered kind, focuses on the motion that occurs between the articulating surfaces of joints When a window washer moves his humerus within the frontal plane (osteokinematics), the head of his humerus spins inside the glenoid fossa (arthrokinematics) (12.3) Kinetics studies forces (such as gravity, friction and pressure) that act on the body to generate or alter motion For instance, the quality of a massage stroke up the thigh (12.4) will depend on your pressure and the resistance you encounter (Did you use lotion?) Kinematics, conversely, involves the analysis of movement in terms of mechanical elements (such as time, space and mass) Back at the table, we’d consider the speed of your stroke and placement of your hands in relationship to your feet (body mechanics) 12.3 Washing windows 12.4 Massaging the hamstrings 168 Trail Guide to Movement arthrokinematics osteokinematics ar-thro-ki-neh-tics ah-stee-o-ki-neh-mat-ics * Google “newton-eyeball-needle” Gait 15.1 You can hop Now that we have all of your parts and pieces together and have stood you upright, we come to our final challenge—to move your body from one place to another by walking As we briefly discussed on page 193, gait (or ambulation) is the manner in which you walk If you activate your standing posture in a forward direction, you’ll generate gait, with features of your upright stance shaping your ambulation Put simply, gait is posture in motion and how you stand will affect how you walk And walking for an upright, bipedal (two-legged) animal— that’s you—is done with a bit of finesse and coordination, to put it mildly Your precarious, upright position has gambled everything on the hopes that your spine can remain on top of your two, vertical lower limbs while in motion With each step you will need to intentionally lose your balance before regaining it, only to promptly lose it again for your next step (In a nutshell, that’s the story of ambulation.) If this oscillation can maintain itself, it will eventually transform into forward mobilization—walking Our plan is to build you a typical ambulatory cycle that is smooth, comfortable and adaptable Eventually, however, your “walk” will include its own quirks and nuances distinct to your personality, moods and physical well-being And regardless of how you (or others) might walk, the components of normal gait are the same Let’s take a closer look 15.2 Skip 15.3 Jump 15.4 Use a walker Step-by-Step GAIT 15.5 OK, maybe not typical ambulation 214 Trail Guide to Movement In order to get you walking, we’ll need to identify the parts of ambulation Let’s begin with the smallest component—a step Walk across a room and notice when your left heel hits the floor followed by your right heel The actions that occur between these two moments is a step—the literal act of putting one foot in front of the other The step length is the distance between your heel strikes Amble slowly through the woods and your step length will shorten; get a move on for free ice cream and it will lengthen Regardless of speed, your step length for each leg should be equal Walk across the room again and this time put two steps together—left heel, right heel, left heel Congrats—you’ve completed a gait cycle (or stride) (Specifically, a left gait cycle) A stride is the events that happen between the time one foot touches the ground and the time it touches the ground again Walking is comprised of an alternating series of left and right gait cycles The distance you traveled during the gait cycle—between your two left heel strikes—is your stride length A Day in the Life of Movement, Part Putting It All Together Over the Course of a Day We began this journey by considering aspects of human movement throughout the course of one 24-hour period (page 6) In the interim, we accomplished nothing less than the construction of a mobile human capable of balance, contraction and coordination Let’s finish this story by walking through another day in the life of movement, revisiting the concepts and designs that proved so essential to physical animation It all started with connective tissue We combined the basic ingredients of this ubiquitous material, relying on its unique array of properties to formulate a variety of designs Then we examined connective tissue structurally and functionally and discovered that some varieties were intended to be compressed, while others to be stretched To fabricate our tensile and compressional elements, we formed a hard, rigid support system (bones), fenders (cartilage), as well as sheets, tubes and cables (fascial tissues) After taking a spin down the meat aisle, we wove all of these components together (with a few buckets of fluid) into a connective tissue network We brought in hammers and saws to build a synovial joint from the bone up Then we explored six types of synovial joints Some were designed for mobility, others for stability We stopped construction for a while to examine the notions of range of motion, endfeel and different types of joint motion Mine Next, we focused on the junctions between the bones that allow movement to occur—joints We went to the circus and learned about planes and axes, and then explored the movements of the body We discovered that joints can be classified either by their structure or by their function 234 Trail Guide to Movement Build a Moving Body! How often are you invited to build a human body capable of movement? Well, here’s your chance Join author Andrew Biel on a fun, extraordinary and fascinating journey into the world of human movement Instead of dissecting the body into smaller, isolated pieces, you’ll take the unique approach of building a body into larger, interconnected elements You’ll begin by designing four key structures essential for movement: n n n n Connective tissue Joints Muscles Nerves Next you’ll apply some biomechanical principles, then finally put the body to the test by exploring the concepts of posture and gait Trail Guide to Movement is written with the same encouraging voice and subtle humor as the author’s iconic Trail Guide to the Body, making the study of human movement easy to understand, captivating and memorable For more information about Trail Guide to the Body and other products from Books of Discovery, please visit booksofdiscovery.com Revised 5th Edition Trail Guide Author Andrew Biel’s acclaimed book, Trail Guide to the Body, is an essential resource for learning musculoskeletal anatomy and palpation Visit our website at booksofdiscovery.com to view sample pages and learn more to the Body NEW! Trigger Point Appendix Included A hands-on guide to locating muscles, bones and more Andrew Biel ... human movement, there are four “prima ballerinas”—mobility, stability, balance and coordination The choreographed participation of all four is required for virtually all of your daily actions Mobility,