Musculoskeletal System and Body Mechanics

Skeletal Muscles:
- Soft tissue that provides motor power for movement.
- Wo I’llMaintains posture XML and generates heat.
Bones:
- Hard connective tissue that creates the rigid structures and shapes of the body.
- Protect vital organs.
- Produce red blood cells.
Tendons and Ligaments:
- Connect muscles to bones (tendons)
- Connect bones to other bones (ligaments)
Synovial Joints:
- Enable motion and flexibility between bones.

The musculoskeletal system and connective tissue work in tandem to:
- Maintain balance
- Coordinate movements
- Ensure good body alignment
Nervous System:
- Composed of the central nervous system and peripheral nervous system.
- Central Nervous System:
  - Includes the brain and spinal cord.
- Peripheral Nervous System:
  - Comprises thousands of nerves interfacing with the spinal cord.
  - Nerves consist of fibers encased in connective tissue for protection.

Although muscle movement is consciously controlled, it is coordinated by the brain.
Cartilage:
- Reduces friction between bones in joints.

Body mechanics involves collaboration between the musculoskeletal system and the nervous system to maintain:
- Posture
- Alignment
- Balance in daily activities
Body mechanics includes activities such as:
- Sitting
- Standing
- Lifting
- Carrying
- Bending
- Lying
Common injuries:
- Lower back pain is prevalent among healthcare workers.
Implementing body mechanics principles reduces risk of injuries by decreasing stress and strain.

Body Alignment:
- The positioning of body parts during activities (posture).
- Optimal posture supports the spine, muscles, and joints.
- Good alignment is based on an imaginary vertical line dividing the body into halves.
- During activities like lifting, keep the back straight, chin level, and tighten abdominal muscles.
Balance:
- Center of Gravity:
  - The central point of weight for an object or body.
  - When standing, the center of gravity is just below the umbilicus.
  - Shifts with changes in position (e.g., bending legs lowers the center of gravity).
- Improved stability occurs when the center of gravity is lower and closer to the base of support.
Body Movements:
- For safe transfers:
  - Keep clients or objects close to the body.
  - Face clients during transfers; pivot feet instead of twisting the spine.
  - Bend knees when picking up objects; use legs instead of back.
- Quadriceps are the largest muscles and should be involved in lifting.

Definition:
- The study of body mechanics concerning work environment demands and equipment design.
Implications of Poor Ergonomics:
- Can lead to frustration, stress, and increased exposure to hazards.
Risk Factors:
- Divided into three areas:
- Practice controls
- Physical characteristics
- Environmental hazards
Benefits of Ergonomics:
- Enhanced work satisfaction
- Increased productivity
- Reduction in injury and fatigue

Mobility:
- The capacity to move without restrictions.
- Requires healthy bones, muscles, and joints.
- Immobility can alter bone structure and musculoskeletal function.
Effects of Bed Rest:
- Even one week can impact movement and daily activities.
- Bones are living tissues that are continuously remodeling.
- Supporting body weight maintains balance in development and breakdown of skeletal tissue.
- Prolonged immobility leads to loss of mass, density, and strength in bones (disuse osteoporosis).
- Definition:
- Demineralization results in fragile bones prone to fractures under minor stress, called fragility fractures.
Muscle Atrophy:
- Occurs due to lack of use; muscles become smaller and weaker.
- Older adults with lower baseline muscle mass are more affected.
- Sarcopenia:
- Loss of lean muscle mass due to deterioration of twitch fibers and voluntary muscles, starting with lower extremities.
- Clients may report weak legs after few days of bed rest.

Structural and functional changes in bones, tendons, ligaments, and cartilage can occur after just four days of bed rest.
Changes in tissue tension, elasticity, and shape lead to joint stiffness and decreased range of motion, particularly in extremities.
Joint Contractures:
- Abnormal fixations of joints due to changes in muscle and connective tissue.
- Flexor muscles are stronger than extensor muscles, potentially leading to contractures that narrow the range of motion.
Foot Drop:
- A specific type of joint contracture causing inability to pull toes up.
- Result from nerve entrapment and shortening of calf muscles; leads to dragged toes while walking.

Prolonged immobility can alter the cardiovascular system after just 24 hours of bed rest.
- Fluid Redistribution:
- Fluids shift to the head, abdomen, and chest, temporarily increasing blood volume returning to the heart.
- Triggers hormonal responses to regulate fluid balance, leading to diuresis and potential dehydration.
- Results in decreased circulating blood volume and increased blood viscosity.
- This effect leads to atrophy of heart muscle known as cardiac deconditioning.
Orthostatic Hypotension:
- A decrease in blood pressure that causes dizziness when sitting or standing.
- Increases risk of falls and complications.
Deep Vein Thrombosis (DVT):
- Development of blood clots in deep veins, typically due to immobility, increased blood viscosity, and muscle atrophy.

Understanding the interrelationship of the musculoskeletal and nervous systems, along with the principles of body mechanics, ergonomics, and the impacts of immobility, are essential for safe and effective body movement and reducing injury risks in healthcare and daily life activities.