Body Regions and Planes of Motion

Body Regions

• The body is divided into axial and appendicular regions
• Axial regions include the cephalic (head), cervical (neck), trunk (thorax, abdomen, pelvis)
• Appendicular regions include the upper and lower limbs

Planes of Motion

• Planes of motion divide the body into imaginary surfaces
• Sagittal plane divides the body front to back
  • Movements include flexion/extension (e.g., biceps curls, knee extensions)
• Frontal plane divides the body side to side
  • Movements include abduction/adduction (e.g., jumping jacks, lateral flexion)
• Transverse plane divides the body top to bottom
  • Movements include rotation (e.g., spinal rotation, forearm pronation)
• Diagonal or oblique planes combine motions from more than one plane

Axes of Rotation

• Movements occur around axes perpendicular to their respective planes
• Frontal axis is side-to-side (e.g., elbow flexion/extension)
• Sagittal axis is front-to-back (e.g., hip abduction/adduction)
• Vertical axis is superior/inferior (e.g., head rotation)

Skeletal System

• Composed of 206 bones, divided into axial and appendicular skeletons
• Axial skeleton includes skull, vertebral column, ribs, and sternum
• Appendicular skeleton includes upper and lower extremities, shoulder, and pelvic girdles
• Functions include protection, support, movement, and mineral storage (hemopoiesis - blood cell formation)
• Types of bones include long (e.g., femur, tibia), short (e.g., carpals, tarsals), flat (e.g., sternum, scapula), irregular (e.g., vertebrae, maxilla), and sesamoid (e.g., patella, bones in tendons like thumb and great toe)

Types of Diarthrodial Joints

• Arthrodial (gliding, plane): limited gliding movement (e.g., carpal bones of the wrist, tarsometatarsal joints of the foot)
• Condyloidal (ellipsoid, biaxial ball-and-socket): movement in two planes without rotation (e.g., wrist, 2nd to 5th metacarpophalangeal joints)
• Enarthrodial (multiaxial ball-and-socket): movement in all planes (e.g., shoulder, hip joints)
• Ginglymus (hinge): wide range of movement in one plane (e.g., elbow, ankle, knee joints)
• Sellar (saddle): reciprocal reception, permits ball-and-socket movement except slight rotation (e.g., thumb carpometacarpal joint)
• Trochoidal (pivot, screw): rotational movement around a long axis (e.g., radioulnar joint)

Goniometry and Movement Terminology

• Goniometry measures range of motion using a goniometer to assess joint angles
• Terms describing movement include flexion (decreasing angle), extension (increasing angle), circumduction (circular movement), rotation (movement around a longitudinal axis), abduction (movement away from the midline), adduction (movement towards the midline), eversion (turning outward), inversion (turning inward), plantar flexion (pointing toes downward), and dorsiflexion (pointing toes upward).
• Additional terms include anatomical position (upright posture, facing forward, palms forward), anatomical directional terminology (e.g., contralateral, ipsilateral, bilateral, deep, superficial), and reference lines (imaginary lines used for anatomical and motion studies)

Joint Classifications

• Synarthrodial (immovable): sutures (skull), gomphosis (teeth in sockets)
• Amphiarthrodial (slightly movable): pubic symphysis, intervertebral discs, rib-sternum joints
• Diarthrodial (freely movable): synovial joints, lubricated by synovial fluid, stabilized by ligaments and bursa sacs (e.g., elbow, knee, hip, shoulder)

Notes on Muscle Structure and Function

• Muscles enable movement by pulling on bones at joints
• Movement depends on muscle fiber orientation and insertion points on bones
• Key structures include tendons (connect muscles to bones), aponeuroses (tendinous expansions of dense connective tissue), and fascia (fibrous connective tissue enveloping muscles, organs, and soft tissues)

Types of Contractions

• Isometric contraction: muscle develops tension without changing length (e.g., holding a weight)
• Isotonic contraction: muscle develops tension with joint movement and can be concentric (muscle shortens) or eccentric (muscle lengthens)

Roles in Movement

• Agonist: primary mover responsible for creating movement
• Antagonist: opposing muscle group that relaxes to allow movement
• Stabilizer: muscle that stabilizes a joint, especially when another muscle crosses multiple joints

Explore the classification of body regions, including axial and appendicular sections. Understand the various planes of motion and how they relate to physical movements in sports and exercise. This quiz will test your knowledge on body mechanics and movements.