Overview
Today's lecture covered the planes of motion, axes of rotation, body regions, types and functions of bones, and bone growth, providing essential foundational concepts in structural kinesiology.
Planes of Motion
- Planes are imaginary two-dimensional surfaces through which body segments move.
- Three main planes: sagittal (divides body into right/left), frontal (divides into anterior/posterior), and transverse (divides into superior/inferior).
- Midsagittal divides the body exactly into right and left halves; parasagittal is off-center.
- Common exercises: sit-ups (sagittal), jumping jacks (frontal), spinal rotation (transverse).
- Diagonal plane involves movement in two or more planes, common in sports (e.g., baseball pitch, football kick, golf swing).
Axes of Rotation
- Axes are perpendicular (90°) to the plane of movement.
- Frontal (mediolateral) axis: runs side to side, for flexion/extension.
- Sagittal (anteroposterior) axis: runs front to back, for abduction/adduction.
- Vertical (longitudinal) axis: runs up and down, for internal/external rotation.
- Diagonal (oblique) axis: at right angle to diagonal plane, involving multiple planes/axes.
Body Regions & Anatomical Terms
- Axial region: head (cephalic), neck (cervical), trunk (thoracic, dorsal, abdominal, pelvic).
- Appendicular region: upper limbs (shoulder, arm, forearm, hand), lower limbs (thigh, leg, foot).
- Common anatomical locations: anterior cubital fossa (front of elbow), inguinal (groin), popliteal fossa (back of knee).
- The adult skeleton has approximately 206 bones: 80 in axial, 126 in appendicular.
Bone Structure & Types
- Long bones: cylindrical shaft with wide ends (e.g., femur, humerus).
- Short bones: small, cube-shaped (e.g., carpals, tarsals).
- Flat bones: curved surfaces (e.g., scapula, ribs, sternum).
- Irregular bones: complex shapes (e.g., vertebrae, ischium, maxilla).
- Sesamoid bones: embedded in tendons (e.g., patella).
- Bone features: diaphysis (shaft), cortex (outer wall), periosteum (outer membrane), endosteum (inner lining), medullary cavity (marrow-filled).
- Epiphyseal plate (growth plate): area of bone growth in children, closes after puberty.
Bone Functions & Growth
- Functions: protection, support, movement (levers), mineral storage, blood cell formation (hemopoiesis).
- Bones grow from hyaline cartilage and ossify as humans mature.
- Bone density and length change across lifespan; trauma to growth plate can halt bone growth early.
Key Terms & Definitions
- Plane â Imaginary flat surface dividing the body for movement analysis.
- Axis â Line about which movement occurs, perpendicular to plane.
- Sagittal Plane â Divides body into right and left halves.
- Frontal Plane â Divides body into front (anterior) and back (posterior).
- Transverse Plane â Divides body into top (superior) and bottom (inferior).
- Epiphyseal Plate â Growth plate in children at ends of long bones.
- Hemopoiesis â Formation of blood cells in bone marrow.
Action Items / Next Steps
- Review and memorize planes of motion and corresponding axes.
- Refresh knowledge of anatomical bone locations and types.
- Prepare for quiz covering planes, axes, and anatomical terminology.