CHAPTER 1 INTRO TO KINESIOLOGY

Foundations and scope

• Kinesiology is the study of motion or human movement.
• Anatomic kinesiology focuses on the musculoskeletal and musculotendinous system.
• Biomechanics applies mechanical physics to human motion.
• Structural kinesiology studies muscles as they participate in movement, involving both skeletal and muscular structures.
• The human body contains bones of varying sizes/shapes and joints that enable or limit movement.
• Muscles vary greatly across the body; there are over 600 muscles in the human body.

Why kinesiology matters

• Professionals who need kinesiology knowledge: anatomists, coaches, strength and conditioning specialists, personal trainers, nurses, physical educators, physical therapists, occupational therapists, physicians, athletic trainers, massage therapists, etc.
• Rationale: understanding large muscle groups, how to strengthen, and why specific exercises are used—not just what to do for conditioning and training.
• Kinesiology + skill analysis helps physical educators understand and improve conditioning; exercise physiology is essential to coaches and educators.

Reference concepts and body positions

• Reference positions provide a basis to describe joint movements:
  • Anatomical position: standing upright, feet parallel, palms forward.
  • Fundamental position: arms at the sides, palms facing the body.
• Key body positions used in musculoskeletal exams and palpation:
  • Fetal, Hook lying, Lateral recumbent, Long sitting, Prone, Short sitting, Supine.
• Summary of positions:
  • Anatomical position is the most widely used for describing movement.
  • Fundamental position differs by arm position.

Common reference lines and landmarks

• Mid-axillary line: vertical line down the lateral surface through the apex of the axilla.
• Mid-sternal line: vertical line down the surface through the middle of the sternum.
• Anterior axillary line: parallel to mid-axillary line, through anterior axillary skinfold.
• Posterior axillary line: parallel to mid-axillary line, through posterior axillary skinfold.
• Mid-clavicular line: vertical line down through the midpoint of the clavicle.
• Mid-inguinal point: midway between ASIS and pubic symphysis.
• Scapular line: vertical line down the posterior surface through the inferior angle of the scapula.
• Vertebral line: vertical line through spinous processes.

Anatomical directional terminology (selected terms)

• Anterior vs. Posterior: front vs. back.
• Anteroinferior / Anterosuperior: in front and below / in front and above.
• Anterolateral / Anteromedial: in front and to the side, toward outer/inner side.
• Anteroposterior: direction relating to both front and rear.
• Posteroinferior / Posterolateral / Posteromedial / Posterosuperior: back and down / back and to the side / back and toward the midline / back and upper part.
• Contralateral / Ipsilateral / Bilateral: opposite side / same side / both sides.
• Inferior (infra) / Superior (supra): below / above.
• Inferolateral / Inferomedial / Superolateral / Superomedial: combinations of inferior/superior with lateral/medial relative to midline.
• Caudal / Cephalic / Rostral: tail/below / head/above / toward the head (front of head).
• Deep / Superficial: deeper vs. near the surface.
• Distal / Proximal / Proximodistal: away from origin vs. nearest trunk/origin; progression from center outward.
• Lateral / Medial / Median: side vs. middle; median line.
• Dexter / Sinister: right side / left side.
• Dorsal / Ventral: back/top of foot vs. belly/front of body.
• Palmar / Volar / Plantar: palm; sole of foot.
• Fibular (peroneal) / Tibial / Radial / Ulnar: lateral/medial aspects of limbs.
• Scapular plane: scapula lies ~30°–45° from the frontal plane.

Alignment and alignment variation terminology

• Anteversion: abnormal/excessive forward rotation in the transverse plane (e.g., femoral anteversion).
• Retroversion: abnormal/excessive backward rotation in the transverse plane (e.g., femoral retroversion).
• Kyphosis: increased posterior thoracic curvature in the sagittal plane.
• Lordosis: increased anterior lumbar curvature in the sagittal plane.
• Scoliosis: lateral curvature of the spine.
• Recurvatum: bending backward in the sagittal plane (e.g., knee hyperextension).
• Valgus: outward angulation of a distal segment in the frontal plane (e.g., knock-knees).
• Varus: inward angulation of a distal segment in the frontal plane (e.g., bowlegs).

Planes of motion and axes

• Planes of motion define imaginary two-dimensional surfaces for movement:
  • There is a 90-degree relationship between a plane of motion and its axis.
• Cardinal planes of motion:
  • Sagittal (AP) Plane: divides body into left and right halves.
  • Frontal (Coronal/Lateral) Plane: divides body into front and back halves.
  • Transverse (Horizontal/Axial) Plane: divides body into upper and lower portions.
• Diagonal planes: movements that combine traditional planes; evident at multiaxial joints (e.g., shoulder, hip).
• Axes of rotation (examples):
  • Frontal axis (X-axis) runs side-to-side; movements commonly include flexion/extension in the sagittal plane.
  • Sagittal/anteroposterior axis (Z-axis) runs front-to-back; movements commonly include abduction/adduction in the frontal plane.
  • Vertical/longitudinal axis (Y-axis) runs top-to-bottom; movements commonly include internal/external rotation in the transverse plane.
  • Diagonal/oblique axes correspond to diagonal planes.

Spine, planes, and diagonal movements (summary via examples)

• Cardinal planes: defined above; used to categorize most human movements.
• Diagonal plane movements are especially notable at the shoulder and hip (e.g., high diagonal and low diagonal movements).
• Typical examples: diagonal abduction/adduction, scapular rotations, shoulder girdle movements, hip/leg diagonal actions.

Body regions and the skeletal system (overview)

• Body regions are divided into:
  • Axial: head/neck (cephalic, cervical), trunk (thoracic, dorsal, abdominal, pelvic).
  • Appendicular: upper limbs and lower limbs (shoulder/arm/forearm/hand and thigh/leg/pedal).
• Axial skeleton includes skull, vertebral column, rib cage, sternum, sacrum, etc.
• Appendicular skeleton includes limbs and girdles (pectoral/pelvic girdles).

Skeletal system: anatomy and functions

• Functions:
  • Protection of internal organs (heart, lungs, brain, etc.).
  • Structural support to maintain posture.
  • Movement by serving as attachment points for muscles and as levers.
  • Mineral storage (calcium and phosphorus).
  • Hemopoiesis (blood cell formation) in red bone marrow of vertebral bodies, femurs, humerus, ribs, sternum.

Types of bones (major categories)

• Long bones: e.g., humerus, fibula.
• Short bones: e.g., carpals, tarsals.
• Flat bones: e.g., skull bones, scapula, sternum, ilium, clavicle.
• Irregular bones: e.g., pelvis bones (ethmoid, vertebrae), ear ossicles, sphenoid.
• Sesamoid bones: e.g., patella; others may be bipartite/tripartite.

Typical bony features and growth

• Diaphysis: long cylindrical shaft.
• Cortex: hard, dense compact bone forming walls of diaphysis.
• Periosteum: fibrous membrane covering the outer surface of the diaphysis.
• Endosteum: fibrous membrane lining the inside of the cortex.
• Medullary (marrow) cavity: contains yellow (fatty) marrow.
• Metaphysis: wider portion between diaphysis and epiphysis.
• Epiphysis: ends of long bones formed from cancellous (spongy) bone; epiphyseal (growth) plate separates diaphysis and epiphysis.
• Epiphyseal plate with separate growth plates; many close by age ~18–25; diameter growth continues throughout life via periosteum activity.
• Apophyses: bony protrusions with growth plates, attachment points for ligaments/tendons (e.g., tibial tuberosity, calcaneus, medial humeral epicondyle).
• Articular cartilage: hyaline cartilage covering joint ends to cushion and reduce friction.

Bone growth and remodeling

• Endochondral bones develop from hyaline cartilage; embryonic hyaline cartilage masses.
• Growth proceeds by ossification centers; longitudinal growth requires open epiphyseal plates.
• After adolescence, epiphyseal plates close; diameter growth continues via periosteal apposition.
• Osteoblasts form bone; osteoclasts resorb bone.
• Bone is composed of
  • calcium carbonate and calcium phosphate (60–70% by weight),
  • water (around 25–30%),
  • collagen provides flexibility and strength; aging reduces collagen, increasing brittleness.
  • ext{Bone composition: } ext{CaCO}3, ext{CaPO}4, ext{collagen}, ext{water}

Bone properties and Wolff’s law

• Outer bone typically cortical; inner cancellous (spongy) bone.
• Cortical bone: low porosity (5–30% nonmineralized tissue); cancellous bone: high porosity (30–90%).
• Cortical bone is stiffer; cancellous bone can undergo greater strain before fracturing.
• Wolff’s law: bone size/shape adapt to habitual mechanical forces; bone mass increases with increased stress over time.

Bone markings (types)

• Processes/elevations/projections: condyle, facet, head; crests, epicondyles, lines, spines, tubercles, tuberosities.
• Cavities/depressions: facet, foramen, fossa, fovea, meatus, sinus, sulcus.
• Apophyseal features: attachment sites for ligaments/tendons.

Joints: classifications

• Articulation (arthrosis): joints enable movement; movement capacity depends on bone configuration, ligaments, and muscles.
• Structural classifications (based on tissue type):
  • Fibrous joints: e.g., sutures, gomphosis; typically immovable (synarthrodial).
  • Cartilaginous joints: e.g., syndesmosis, symphysis, synchondrosis; allow slight movement (amphiarthrodial).
  • Synovial joints: diarthrodial; freely movable with a synovial capsule and fluid.
• Functional classifications (based on movement): Diarthrodial joints cover various classes and degrees of freedom.
• Structural-functional mapping includes synarthrodial, amphiarthrodial, and diarthrodial joints, with specific sub-types.

Diarthrodial (synovial) joints: core features

• Freely movable joints with a joint capsule and synovial fluid.
• Capsular thickening forms ligaments/supports against abnormal movement.
• Articular (hyaline) cartilage covers joint ends to absorb shock and reduce friction, and can absorb synovial fluid during unloading.
• Some diarthrodial joints include fibrocartilage disks (e.g., menisci, labrums) for shock absorption, load distribution, and stability.
• Degrees of freedom (DOF): number of independent directions a joint can move.
  • 1 DOF = movement in one plane,
  • 2 DOF = movement in two planes,
  • 3 DOF = movement in three planes.

Diarthrodial joints: six structural types

• Arthrodial (gliding): two flat/plane surfaces; limited movement individually but multiple articulations enable motion; examples: vertebral facets, intercarpal, intertarsal joints.
• Ginglymus (hinge): uniaxial; motion in one plane (e.g., elbow, knee, talocrural joint).
• Trochoid (pivot): uniaxial; rotation around a longitudinal axis (e.g., atlantoaxial joint, radioulnar joints).
• Condyloid (knuckle): biaxial with an oval concave surface articulating with an oval convex surface; e.g., MCP joints; allows flexion/extension and abduction/adduction.
• Enarthrodial (ball-and-socket): multiaxial/triaxial; ball fits into a socket (e.g., hip, shoulder); motions include flexion/extension, abduction/adduction, diagonal movements, rotation, circumduction.
• Sellar (saddle): triaxial; two reciprocally concave/convex surfaces; e.g., 1st carpometacarpal joint at the thumb; allows multiple directions with a degree of rotation.

Stability vs mobility in diarthrodial joints

• Structural (static) stability: primarily from bony architecture, cartilage, ligaments, and connective tissue laxity.
• Functional (dynamic) stability: from muscles, proprioception, motor control, and neuromuscular coordination.
• Principle: increased stability often reduces mobility, and increased mobility often reduces stability. Both heredity and biomechanics (Wolff’s law for bone, Davis’ law for soft tissues) influence these properties.
• Key factors affecting joint stability/mobility:
  • Bones: joint architecture, depth/shallowness, bilateral comparisons.
  • Cartilage: hyaline cartilage and specialized structures (menisci, labra).
  • Ligaments & connective tissue: static restraints; variation in laxity relates to elastin vs. collagen balance.
  • Muscles: dynamic stability through active contraction; strength, endurance, and flexibility matter.
  • Proprioception & motor control: neuromuscular regulation for appropriate muscle activation and joint protection; integration with CNS.
• Risks when stability is compromised: tendinitis, bursitis, arthritis, internal derangements, joint subluxations.

Open-packed vs close-packed joint positions

• Close-packed position: maximal stability and congruence, minimal joint volume; ligaments/capsule taut; typically at end-range extension for many joints; examples: full knee/hip/elbow extension.
• Open-packed (loose-packed) position: ligaments/capsule slackened; maximal joint space; minimal surface contact; greater distraction; typically mid-range of motion (e.g., ~70° elbow flexion, ~25° knee flexion, ~30° hip flexion with abduction).

Movements in joints and range of motion (ROM)

• ROM: the area through which a joint may normally be moved; measurable in degrees.
• Goniometer: instrument to measure joint angles; axis aligned with joint’s axis of rotation; arms align with longitudinal axes of adjacent bones.
• ROM range notation: degrees from 0° to a maximum value; normal ROM varies among individuals.
• Change in position terminology (kinematics): angles between bones change; movement occurs between articular surfaces.
• Examples of ROM descriptions:
  • Knee: flexion from extension to approximately 140°; flexion increases as heel approaches buttocks.
  • Knee: starting at 90° flexion and moving to 120° results in a knee flexion angle of 120° (even though the knee flexed only 30°).
  • Knee extension from 90° flexion to full extension can yield a flexion angle of 50° if you measure in context of starting position.
• Prefixes with movement terms indicate motion direction and range (hyper- and hypo- as emphasis).

Movement terminology (general concepts)

• Abduction: movement away from anatomical position in the lateral plane.
• Adduction: movement toward midline in the lateral plane.
• Flexion: bending that reduces the joint angle (usually in the sagittal plane).
• Extension: straightening that increases the joint angle (usually in the sagittal plane).
• Circumduction: circular movement describing an arc, combining flexion, extension, abduction, and adduction; occurs at shoulder and hip with a fixed point.
• Diagonal abduction/adduction: movements through a diagonal plane away from/toward midline.
• External rotation: rotation around the longitudinal axis away from the midline (transverse plane).
• Internal rotation: rotation around the longitudinal axis toward the midline (transverse plane).

Specific joint fundamentals and icons (high-level summaries)

• Ankle & Foot (subtalar & transverse tarsal):
  • Eversion/Inversion in frontal plane; dorsiflexion (ankle) and plantarflexion; pronation (dorsiflexion + eversion + forefoot abduction) and supination (plantarflexion + inversion + forefoot adduction).
• Radioulnar joint: pronation (radius crosses ulna) and supination (radius parallel to ulna).
• Shoulder girdle (scapulothoracic): depression/elevation; protraction/retraction (abduction/adduction of scapula); rotation (upward/downward) of the scapula.
• Glenohumeral (shoulder) joint: horizontal abduction/adduction; flexion/extension; abduction/adduction in scapular plane (scaption); external/internal rotation.
• Spine: lateral flexion (side bending) with reduction/adduction back to neutral.
• Wrist and hand: palmar (volar) flexion, dorsal flexion; radial/ulnar deviation; opposition and reposition of the thumb; retropulsion of the thumb.
• Hip, knee, ankle, great toe joints: flexion/extension, abduction/adduction, internal/external rotation; MTP, PIP, DIP movements in the toes; detailed ROM examples provided for each region.

Movement icons and diarthrodial joint movements

• Movement icons illustrate scapula movements (elevation/depression, abduction/adduction, upward/downward rotation).
• Glenohumeral movements include flexion/extension, abduction/adduction, horizontal movements, and rotations.
• Elbow, radioulnar, wrist movements include flexion/extension, pronation/supination, radial/ulnar deviation, and wrist movements (abduction/adduction).
• Hip/knee/ankle/foot movements include flexion/extension, abduction/adduction, external/internal rotation, plantar/dorsiflexion, inversion/eversion.
• Great toe movements involve MTP/IP flexion/extension; similar multi-joint movements occur in other digits (MCP, PIP, DIP).

Physiological movements vs. accessory motions

• Physiological movements: voluntary bone movements driven by muscle activity (e.g., flexion, extension, abduction, adduction, rotation).
• Osteokinematic motion: the resulting bone motion in relation to the cardinal planes.
• Accessory motions: motion between articular surfaces necessary for full physiological motion; cannot occur without joint compression or distraction.
• Types of accessory motion: spin, roll, glide.
• Relationship (concave-convex rule):
  • When a convex joint surface moves on a concave surface, roll and glide occur in opposite directions.
  • When a concave surface moves on a convex surface, roll and glide occur in the same direction.
• Examples:
  • Tibiofemoral joint (convex femur on concave tibia) during flexion/extension requires backward glide of the femur as it rolls forward.
  • Standing knee extension demonstrates the opposite: tibia moves forward on a stationary femur with forward rolling/gliding.
• Spin may occur alone or with roll and glide; knee demonstrates medial/internal rotation during full extension.
• Clinical relevance: absence of accessory motions limits physiological motion; improper roll/glide can reduce ROM or cause joint compression.

Open/closed packed positions: practical implications

• Close-packed positions provide maximal contact and stiffness, minimizing distraction; ligaments taut; joint less tolerant of separation.
• Open-packed positions provide maximal congruency loss and space; ligaments slackened; joint more permissive to movement and distraction.
• Examples/typical positions often cited: full extension of knee, hip, elbow (close-packed); mid-range positions (open-packed).

Practical notes on ROM measurement and interpretation

• ROM is measured in degrees with a goniometer; each joint has normal ranges that vary between individuals.
• ROM descriptions can be contextual depending on starting position and reference axis.
• ROM can be affected by structural integrity, proprioception, neuromuscular control, and prior injury.

Connections to broader principles and real-world relevance

• Wolff’s law: bone adapts to the loads it experiences; training and load management influence bone density and geometry.
• Davis’ law: soft tissues adapt to tension with lengthening or shortening over time; tissue laxity influences stability.
• The interplay of stability and mobility is central to injury prevention and rehabilitation: too much mobility without adequate stability increases injury risk; excessive stiffness can limit function.
• Knowledge of planes, axes, and joint types informs exercise selection, technique analysis, and performance optimization in sports and daily activities.

Formulas, numerical references, and key values (LaTeX)

• ROM range notation: 0^ ext{o} ext{ to } ext{max}^ ext{o} \text{e.g., knee flexion to } 140^ ext{o} ext{ (approx.)}
• Directional/plains relationships: 90^ ext{deg} ext{ between a plane of motion and its axis}
• Bone composition: 60 ext{-}70 ext{ ext{%}} ext{ CaCO}3/ ext{CaPO}4, ext{ 25–30% water}
• Long bone growth observations: epiphyseal plates open for longitudinal growth; plates close by ages ~18–25; diameter growth continues throughout life.
• Anteversion angle example: 15^ ext{o} ext{ to } 25^ ext{o} (normal); excessive anteversion > 25^ ext{o}; retroversion < 10^ ext{o}.
• Diathrodial joints degrees of freedom: 1, 2, or 3 DOF depending on joint type.
• Examples of ROM values: elbow flexion/extension, knee flexion ~140^ ext{o}, hip flexion/abduction ~30^ ext{o} in open-packed position.

Web resources (quick-reference ideas)

• Arthrokinematics concepts (roll, glide, spin) and convex-concave rule explanations.
• Interactive anatomy and joint movement sites for practice with joint diagrams and motion demonstrations.
• Useful for visualizing open vs. close packed positions and common joint mechanics.

Quick-reference checklist (study aids)

• Define: kinesiology, anatomic kinesiology, biomechanics, structural kinesiology.
• List the six types of diarthrodial joints and give a representative example of each.
• State the three cardinal planes and three primary axes with their orientation.
• Explain Wolff’s and Davis’ laws and their practical implications for training and rehab.
• Describe open-packed vs close-packed joint positions and provide examples.
• Distinguish physiological movements from accessory motions; explain the concave-convex rule with one convex/concave example for the knee.
• Memorize the key ROM terms (flexion, extension, abduction, adduction, rotation, circumduction) and their plane associations.
• Review the major bone types and typical features (diaphysis, epiphysis, metaphysis, periosteum, endosteum, cortex, cancellous bone).
• Be able to identify and describe the roles of major ligaments, cartilage structures (menisci, labra), and joint capsules in stability.