Chapter 1: kinesology online class

Anatomical Position vs Fundamental Position

  • Anatomical position is the reference starting position for the course and movement analysis.

    • Posture: upright, feet parallel or touching, head upright.

    • Palms face forward.

    • This position is used as the starting reference for every movement phase.

  • Fundamental position is similar to anatomical position but with palms facing the sides (thumbs pointing away from the body).

    • Commonly used during walking, object manipulation, or pronated palm positions.

  • Key difference:

    • Anatomical position: palms forward.

    • Fundamental position: palms facing the body sides (anterior surface of the body not exposed to the front).

  • Practical note: the body is treated as a cheat sheet for locating and palpating landmarks; positions help highlight bony landmarks.

Other reference body positions (overview used in demonstrations)

  • Fetal position: curled up.

  • Hook line position (recumbent, supine with knees bent): lying on the back with hips and knees flexed so feet are on the table.

  • Lateral recumbent (lateral decubitus): lying on one side; common in ultrasonography for heart conditions.

  • Long sitting: legs straight out in front on the table/plinth.

  • Short sitting: knees bent and hanging off the edge of the table.

  • Prone: lying face down.

  • Supine: lying face up.

  • Right lateral decubitus: lying on the right side; description requires specifying the side (e.g., right lateral recumbent) for clarity.

  • Important note: leg/tendon tension (e.g., hamstrings) varies with position and can affect pelvic movement; long sitting vs short sitting changes hamstring tension.

  • Descriptive language matters when describing recumbent positions to other clinicians.

Anatomic terminology: directional terms and orientation

  • Anterior (ventral): toward the front of the body.

  • Posterior (dorsal): toward the back of the body.

  • Superior (cephalic, cranial): toward the head.

  • Inferior (caudal): toward the feet/tail.

  • Antero- vs postero- prefixes describe front/bac k positions relative to other structures; e.g., antero-inferior = front and below.

  • Antero- superior = front and above.

  • Lateral vs medial:

    • Lateral: toward the outside, away from the midline.

    • Medial: toward the midline.

  • Examples: antero-lateral, antero-medial, postero-lateral, postero-medial, etc.

  • Contralateral: on the opposite side of the body.

  • Ipsilateral: on the same side of the body.

  • Bilateral: on both sides.

  • Inferior/ superior can combine with medial/lateral to describe movement directions (e.g., moving inferior and medial).

  • Median: near the midline; often used in relation to midsagittal plane concepts.

  • Right vs left terms: dextor (right), sinister (left).

  • Foot and hand specifics:

    • Dorsum of the foot: the top of the foot.

    • Plantar surface (plantar flexion): bottom/sole of the foot; plantar flexion = pointing toes downward toward the plantar surface.

    • Dorsal surface of the hand: the back of the hand; palmar (volar) aspect = palm.

    • Palmar vs volar are commonly used for the hand; dorsal for the back of the hand.

    • Radial side: thumb side (lateral in the upper limb); Ulnar side: medial side.

  • Limbs relative to midline:

    • Proximal: closer to the trunk.

    • Distal: farther from the trunk.

  • Proprioceptive and directional cues: orientation terms help describe rotations and positions in rehabilitation and movement analysis.

  • Special directional terms for spine and head: rostral (toward the face/front of head); cephalic (head region); sagittal references often tie to anterior-posterior orientation.

Planes and axes of movement

  • Cardinal planes (movement occurs within these imaginary planes):

    • Sagittal plane (anterior-posterior plane): divides body into left and right halves. Movement within this plane includes flexion and extension.

    • Frontal plane (coronal plane, lateral plane): divides body into anterior and posterior halves. Movement includes abduction/adduction.

    • Transverse plane (horizontal plane, axial plane): divides body into superior and inferior halves. Movement includes internal/external rotation.

  • Diagonal planes: combinations of the traditional planes allowing multi-planar movement (e.g., high diagonal, low diagonal actions).

  • Axes of motion (perpendicular to planes): terminology varies; common practice in the lecture uses various labels (some call axes X, Y, Z; others use mediolateral, anteroposterior, vertical).

    • A plane and its axis form a pair: movement occurs about an axis perpendicular to the plane.

    • Important caveat: multiple naming conventions exist; pick one and stay consistent; you may annotate with alternate names on a cue card for exams.

  • Cardinal planes and typical movements:

    • Sagittal (AP) plane: flexion/extension; axis = mediolateral (left-right) in standard biomechanics; some lectures discuss axes as anterior-posterior or frontal depending on convention.

    • Frontal (coronal) plane: abduction/adduction; axis = anterior-posterior (front-to-back) in standard biomechanics; other conventions exist.

    • Transverse (axial) plane: internal/external rotation; axis = vertical/longitudinal (head-to-toe direction).

  • Memorization aids (three core sentences):

    • ext{Flexion and extension take place in the sagittal plane (anteroposterior plane) about a lateral/coronal/frontal axis.}

    • ext{Abduction and adduction take place in the frontal/coronal plane about an axis that runs anterior to posterior.}

    • ext{Internal and external rotation take place in the transverse/horizontal plane about an axis that runs up and down.}

  • The instructor notes that you should choose a language family (names for planes/axes) you’re comfortable with and stick to it, possibly marking alternatives on a small note for exams.

  • Practical tip: combine planes and axes language when studying and practicing movement analysis.

Body regions and the skeletal system (overview of regions)

  • Body regions are named by key features (e.g., cervical region = neck; lumbar region = low back).

  • Axial skeleton: head, neck, trunk (midline structures).

  • Appendicular skeleton: upper and lower limbs (arms and legs).

  • Head and trunk details:

    • Cephalic region (cranium and facial structures).

    • Cervical spine (neck) has distinct handling but is part of the spine; trunk includes thoracic and lumbar regions and pelvis.

  • Upper and lower extremities: divisions within each limb (e.g., shoulder, elbow, forearm, hand; hip, knee, ankle, foot).

  • Pedal region: foot region terminology.

  • The skeletal system is studied through a region-based approach to movement and function.

The bone: osteology and structure

  • Approximate adult bone count: ~206 bones (variation exists with some extra/separate sesamoid bones).

  • Major roles of the skeleton:

    • Protection of vital organs (heart, lungs, brain, etc.).

    • Support and upright posture.

    • Lever system for muscles and ligaments via attachments (tendons and ligaments connect to specific bone sites).

    • Mineral storage (calcium and phosphorus) and hormonal/electrolyte roles.

    • Hematopoiesis: red blood cell production in red marrow within certain bones.

  • Bone types (structural categories): long, short, flat, irregular, sesamoid.

    • Long bones: longer than wide; hollow central cavity; sites of hematopoiesis; examples: radius, ulna, humerus, femur, metacarpals, metatarsals, etc.

    • Short bones: small with large articular surfaces; examples: carpals, tarsals (mosaic-like; many joints within the hand/foot).

    • Flat bones: thin, curved with protective/attachment surfaces; examples: scapula, sternum, some skull bones.

    • Irregular bones: irregular shapes; examples: sphenoid, jawbone, vertebrae, ischium.

    • Sesamoid bones: embedded in tendons to form pulley systems (e.g., patella, sesamoids at tendon insertions).

    • Bipartite or tripartite bones: one bone that appears as two or three pieces attached (e.g., bipartite patella).

  • Endochondral bone growth: bones start as cartilage and ossify over time; growth plates (epiphyseal plates) are cartilaginous regions that allow lengthwise growth; once closed, length growth ceases.

  • Growth plates and apophyses:

    • Epiphyseal plates: thin cartilage plates between diaphysis and epiphysis; responsible for longitudinal growth.

    • Apophyses: tendon/ligament attachment sites near growth plates; prone to apophysitis in adolescents (e.g., Osgood-Schlatter, Sever’s disease).

    • Osgood-Schlatter (tibial tuberosity apophysitis) and Sever’s disease (calcaneal apophysitis) are common adolescent conditions.

  • Cartilage and joint surfaces:

    • Articular cartilage: hyaline cartilage covering ends of bones at joints; provides cushioning and friction reduction; relatively avascular and rely on synovial fluid and loading cycles for nutrition.

    • When cartilage wears, bone-on-bone contact can occur, contributing to osteoarthritis symptoms.

    • Joints may also involve articular discs (menisci in the knee) and labra (shoulder/hip) to enhance stability and congruence.

  • Bone biology basics:

    • Bone matrix: ~70% minerals (calcium phosphate/calcium carbonate) with water and a small collagen component; collagen provides structural integrity with limited elasticity.

    • Osteoblasts/build bone and osteoclasts/resorb bone; balance maintains bone density.

    • Periosteum: dense fibrous outer covering; attachment site for tendons/ligaments; supports bone protection and repair.

    • Endosteum: inner lining of bone cavity; plays role in remodeling.

    • Medullary (marrow) cavity: contains yellow (fatty) marrow in adults; red marrow in some regions for hematopoiesis.

  • Bone remodeling and aging:

    • Wolf's Law: bone adapts to the stresses placed on it; higher stress leads to increased bone density (mineral deposition) and modeling to strengthen bone against expected loads.

    • Davis's Law: soft tissues (ligaments, joint capsules, muscles, tendons) adapt to stresses (shorten/lengthen); prolonged changes in length lead to lasting adaptations.

    • Examples: apophysitis, osteoarthritis risk reduction with appropriate loading; aging reduces collagen synthesis and bone density, leading to osteopenia/osteoporosis risks.

Joints: structure, classification, and function

  • Joints (arthro-): where movement occurs; three major classifications:

    • Synarthrodial (fibrous joints): immovable joints (e.g., skull sutures, gomphosis teeth in sockets).

    • Amphiarthrodial (cartilaginous joints): limited, slight movement (e.g., pubic symphysis, intervertebral discs).

    • Diarthrodial (synovial joints): freely movable joints with a joint capsule and synovial fluid; main focus of this course.

  • Synovial joint components:

    • Joint capsule (fibrous), reinforced by ligaments.

    • Synovial fluid bathes articulating surfaces; articular cartilage covers ends of bones.

    • Labrum, menisci, and articular cartilage contribute to stability and congruence.

  • Types of diarthrodial (synovial) joints (six main types):

    • Arthrodial (gliding) joints: two flat surfaces glide; examples include carpal joints and vertebral facets.

    • Hinge joints: uniaxial, move in one plane (flexion/extension); examples include elbow and interphalangeal joints.

    • Pivot (trochoid) joints: uniaxial rotation around a single axis; examples include atlantoaxial joint and proximal radioulnar joint.

    • Condyloid (ellipsoidal) joints: biaxial; convex on one side, concave on the other; examples include radiocarpal joint (wrist).

    • Ball-and-socket joints: multiaxial, three degrees of freedom; examples include shoulder and hip.

    • Saddle (sellar) joints: triaxial with unique concave-convex geometry; thumb carpometacarpal joint is the classic example.

  • Joint stability vs mobility (trade-off): more mobility often means less static stability; more static stability often means less mobility.

    • Static stabilizers: bone architecture, labrums, menisci, joint capsules, ligaments; some cannot be changed with training.

    • Dynamic stabilizers: muscles, tendons, proprioception, motor control, and neuromuscular coordination.

    • Proprioception and motor control contribute to joint stability during movement.

  • Three laws of tissue adaptation applied to joints:

    • Wolf's Law (bone adaptation to load).

    • Davis's Law (soft tissue adaptation to load).

    • Clinical implications: proper loading can strengthen joints; excessive loading or immobilization can cause stiffness or instability.

  • Practical rehabilitation concepts:

    • Joint mobilizations used by clinicians to stretch connective tissues when necessary.

    • Proprioception/motor control training improves stability during movement.

    • Open vs closed kinetic chain concepts affect how joint surfaces move and how roll/glide occur.

  • Movement terminology recap (coupled with examples):

    • Flexion/extension: sagittal plane; decrease/increase of joint angle.

    • Abduction/adduction: frontal plane; movement away from/toward midline.

    • Internal (medial) and external (lateral) rotation: transverse plane; rotation about a vertical axis.

    • Circumduction: combined movement in multiple planes (flexion + extension + abduction + adduction).

    • Diagonal movements: high/low diagonals combining planes (e.g., diagonal abduction/adduction).

    • Pronation/supination: forearm movements (palm orientation in the transverse plane).

    • Dorsiflexion/plantar flexion: foot movements; dorsum toward shin vs plantar toward sole.

    • Inversion/eversion: foot movements around a longitudinal axis.

    • Radial/ulnar deviation: hand/wrist movements toward radial (thumb) or ulnar (pinky) sides.

    • Elevation/depression, protraction/retraction, and scapular rotations for the shoulder girdle.

    • Lateral flexion: side bending of the spine.

    • Reduction: returning to neutral after lateral flexion.

    • Opposition/reposition: thumb contact with fingers and return to neutral.

  • Movement notation: think in terms of joint movements (bone positions), not muscles themselves; a muscular contraction produces joint movement, not the action label by itself.

  • Normal ranges of motion (ROM): assessed with a goniometer (360-degree device) or inclinometer; concept of 0–180 degrees used for simplicity; actual normal ranges vary by joint and region; emphasis is understanding relative angles rather than exact numeric normal values.

The physiology of the musculoskeletal system: integration into movement

  • The body as a lever system: bones act as levers, joints as fulcrums, muscles as drivers; ligaments and tendons provide force transmission and guidance.

  • Open vs closed kinetic chain examples:

    • Open chain: distal segment moves freely (e.g., knee extension machine); movement of a single joint with the other segments free.

    • Closed chain: distal segment fixed (e.g., squat); multiple joints move in a coordinated fashion with proximal stabilization.

  • Practical take-home: for rehabilitation, understanding which bone is fixed vs moving changes the direction of accessory movements (roll vs glide) and how to approach training safely.

Measurements and practical assessment tools

  • Goniometer: primary tool for measuring joint ROM in degrees (0–180 typically used as reference).

  • Inclinometer: used in some contexts (e.g., spine ROM) for more precise angle measurement.

  • Concept: use ROM measures to track changes due to rehabilitation, training, or pathology; ROM improvements reflect adaptation of bones, cartilage, and soft tissues (per Wolf’s and Davis’s laws).

  • Important practical notion: normal ROM is region-specific and not universally fixed; focus on relative movement quality and functional ability rather than a single universal number.

Putting it all together: chapter wrap-up ideas

  • Movement is a joint effort between bone (structure) and soft tissues (muscles, ligaments, tendons, cartilage).

  • Proper movement relies on matching stability with mobility (the C-principle): too much stability may impede movement; too much mobility can risk injury.

  • The body’s tissues adapt with loading: bones undergo remodeling (Wolf’s Law) and soft tissues adapt (Davis’s Law).

  • Mastery comes from building a consistent language set (planes, axes, and movement terminology) and using tools like goniometers to quantify progress.

  • Final note: nomenclature in this course includes multiple naming conventions for planes/axes; focus on consistency within your own notes and be able to translate between common synonyms when needed.

Quick reference terms (condensed definitions)

  • Epiphysis: end of a long bone separated from the shaft by the growth plate; site for joint articulation.

  • Diaphysis: shaft of a long bone; contains the medullary cavity; cortical (compact) bone forms the hard outer shell.

  • Periosteum: outer fibrous membrane covering bone; attachment site for tendons/ligaments.

  • Endosteum: inner lining of bone's medullary cavity.

  • Medullary cavity: central cavity of bone containing yellow (fatty) marrow in adults; red marrow in some regions.

  • Articular cartilage: hyaline cartilage covering joint ends; reduces friction and absorbs load.

  • Labrum/menisci: fibrocartilaginous structures that improve joint congruence and stability.

  • Growth plate (epiphyseal plate): cartilage zone for longitudinal bone growth in children.

  • Apophysis: tendon/ligament attachment site near growth plates; prone to apophysitis in adolescence.

  • Osteoblasts/osteoclasts: bone-forming vs bone-resorbing cells; balance governs bone density.

  • Wolff's Law: bone adapts to the loads it experiences.

  • Davis's Law: soft tissues adapt to the stresses placed on them.

  • Synarthrodial: immovable joints (e.g., skull sutures).

  • Amphiarthrodial: slightly movable joints (e.g., pubic symphysis).

  • Diarthrodial: freely movable joints with a synovial capsule.

  • Six diarthrodial types: gliding (arthrodial), hinge, pivot, condyloid, ball-and-socket, saddle.

  • Degrees of freedom: how many planes a joint can move in (1, 2, or 3).

  • Accessory joint motions (arthrokinematics): roll, glide, spin; depend on concave-convex relationships.

  • Open kinetic chain vs closed kinetic chain: distal segment moves freely vs fixed.

  • ROM measurement: use goniometer; degrees of freedom give a practical sense of joint flexibility.

  • Common clinical conditions mentioned: Osgood-Schlatter disease, Sever’s disease, apophysitis, avulsion fractures, osteopenia/osteoporosis (context of aging bones).