Kinesiology: Planes and Axes of Motion

Planes of Motion

• Transverse plane: Involves rotation.
• Frontal plane: Involves side-to-side movements.
• Sagittal plane: Involves front-to-back movements.

Axes of Motion

• Sagittal axis: Responsible for flexion and extension (e.g., knee, elbow).
• Frontal axis: Responsible for abduction and adduction (ab = away from the center, ad = towards center).
• Transverse axis: Responsible for internal and external rotation (in = towards the center, ex = away from center).
• Supination and pronation relate to hand and foot positions.

Anatomical Directions

• Superior: Higher position; inferior: lower position (e.g., head to elbow).
• Medial: Closer to the center; lateral: further from the center.
• Proximal: Closer to the center of the body; distal: farther from the center along extremities.
• Dorsum: The top side; plantar: the bottom side of the feet.
• Deep: Closer to the center; superficial: on the surface.

Your Skeleton

• Bones: Adapt shape based on functional loading; Wolff’s Law focuses on genetic influence, while Roux’s Law addresses developmental response to stress.
• Cartilage: Types include hyaline (smooth surfaces) and fibrous (shock absorption); it's avascular and overexertion leads to injury.
• Joints: Differentiated into immovable versus articulating; require synovial fluid and have observable movement patterns like flexion and extension.
• Joint Capsule: Provides stability via fibrous tissues, allows for range of motion (hypo, normal, hypermobility), and nourishes synovial fluid.

Types of Synovial Joints

• Ball & Socket: Capable of movement in all three planes (e.g., hip, shoulder).
• Hinge: Allows movement in one direction (e.g., knee, elbow).
• Plane/Gliding: Facilitates movement in multiple planes (e.g., spine, wrists).
• Pivot: Allows rotation around a single axis (e.g., neck).

Connective Tissue

• Ligaments: Connect bone to bone, characterized as inelastic and avascular; they help nourish cartilage.
• Tendons: Connect muscle to bone; tendons vary in elasticity and also lack blood supply.
• Bursa: Fluid-filled sacs that reduce friction between tendons and ligaments over bones.

Muscles

• Govern voluntary movement and specific to their functions based on shape and fiber arrangement.
• Skeletal Muscle: Contracts due to sliding protein mechanisms; has optimal lengths for contraction.
• Motor Unit: Comprises all muscle cells connected to a single nerve.
• All or None Law: All muscle fibers within a motor unit contract maximally or not at all.

Peripheral Nervous System

• Afferent neurons send messages from the body to the brain.
• Efferent neurons bring responses from the brain back to the body, facilitating reflex actions.

Reflexes

• Stretch Reflex: A protective, quick two-neuron response.
• Reciprocal Inhibition: A more complex three-neuron response allowing one muscle to relax while its antagonist contracts.

Contractions

• Isometric: Force production without length change (e.g., squeezing a fist).
• Concentric: Force while muscle shortens (most straightforward).
• Eccentric: Force while muscle lengthens, requiring more effort and common in functional movements.

Pathology

• Traumatic Injury: Rare and caused by accidents; focus on enhancing proprioception and stability.
• Repetitive Injury: Common from consistent activity; necessitates well-rounded conditioning for muscle imbalances.
• Overuse Injury: Develops over time due to imbalances; training program should adapt to load stresses.
• Types of Injuries: Includes sprains (ligament injury), strains (muscle injury), and fractures (either traumatic or stress-induced).

Injury Rehab

• For fractures, immobilization and gradual loading are crucial.
• Sprains require rest, immobilization, and progressive loading of the affected area.
• Strains benefit from rest followed by gradual loading.
• Manage inflammatory injuries (itis) by resting and then gradually loading affected muscles and tendons.

Reduction of Risk

• Emphasizes the necessity of proper loading to prevent injuries and improve overall functionality.