Movement, Exercise, and the Musculoskeletal System: Foundations for Personal Health

Ch: 34 Activity

Role of the Skeletal System in Movement

The skeletal system provides the structural framework for the body and is essential for movement and protection of vital organs.

• Support: Maintains the shape and form of the body by supporting soft tissues.

• Protection: Shields crucial organs (e.g., skull protects the brain, ribs protect the heart and lungs).

• Attachment Surfaces: Offers surfaces for muscles, tendons, and ligaments to attach, enabling movement.

• Storage: Stores minerals (such as calcium and phosphorus) and fat within bone marrow.

• Blood Cell Production: Produces red and white blood cells and platelets in the bone marrow (hematopoiesis).

Bones Classified by Shape

Bones are categorized based on their shapes, which relate to their functions.

• Long bones: Found in the upper and lower extremities (e.g., femur, humerus); important for movement and support.

• Short bones: Located in the wrist (carpals) and ankle (tarsals); provide stability and some movement.

• Flat bones: Thin and often curved (e.g., ribs, skull bones); protect internal organs and provide broad surfaces for muscle attachment.

• Irregular bones: Complex shapes (e.g., vertebrae, jaw); serve various functions including protection and support.

Example: The bones in the wrist are classified as short bones.

Freely Movable Joints

Joints are connections between bones that allow for varying degrees of movement. Freely movable joints (synovial joints) are essential for mobility.

• Ball and socket: Allow movement in all directions (e.g., shoulder, hip).

• Condyloid: Permit movement but no rotation (e.g., wrist).

• Gliding: Allow bones to glide past one another (e.g., intercarpal joints of the wrist).

• Hinge: Permit bending and straightening (e.g., elbow, knee).

• Pivot: Allow rotation (e.g., atlas and axis in the neck).

• Saddle: Allow movement back and forth and side to side (e.g., thumb).

Relationship of Skeletal Muscles to Bones

Skeletal muscles attach to bones via tendons and produce movement by contracting and pulling on the bones, acting as levers.

Muscle Types and Functions

Three Types of Muscles

• Skeletal muscle: Voluntary muscles attached to bones; responsible for body movement.

• Cardiac muscle: Involuntary muscle found only in the heart; responsible for pumping blood.

• Smooth (visceral) muscle: Involuntary muscle found in walls of internal organs (e.g., intestines, blood vessels).

Important Functions of Muscles

• Motion: Movement of body parts and locomotion.

• Maintenance of posture: Stabilizes body positions.

• Support: Supports soft tissues and organs.

• Heat production: Muscle activity generates heat, helping maintain body temperature.

Joint Movements

Types of Joint Movements

Joints allow for a variety of movements essential for daily activities.

• Abduction: Movement away from the midline of the body.

• Adduction: Movement toward the midline.

• Circumduction: Moving a limb in a circular motion (e.g., arm circles).

• Flexion: Decreasing the angle between two bones (bending).

• Extension: Increasing the angle between two bones (straightening).

• Hyperextension: Extension beyond the normal range of motion.

• Dorsiflexion: Bending the foot upward at the ankle.

• Plantar flexion: Bending the foot downward at the ankle.

• Rotation: Turning a bone around its own axis.

• Internal rotation: Rotation toward the center of the body.

• External rotation: Rotation away from the center of the body.

• Supination: Turning the palm upward.

• Pronation: Turning the palm downward.

• Inversion: Turning the sole of the foot inward.

• Eversion: Turning the sole of the foot outward.

Example: Moving a patient's leg in a circle is an example of circumduction.

Nervous System and Muscle Contraction

Effect of the Nervous System on Muscle Contraction

The nervous system controls muscle contraction through a series of signals:

• Afferent neurons: Carry sensory information from the body to the central nervous system (CNS).

• Processing: The CNS interprets the information and formulates a response.

• Efferent neurons: Transmit the response from the CNS to skeletal muscles via the somatic nervous system, resulting in movement.

Postural Reflexes

• Labyrinthine sense: Sensory organs in the inner ear help maintain balance and posture.

• Proprioceptor or kinesthetic sense: Sensory receptors in muscles and joints provide information about body position and movement.

• Visual or optic reflexes: Visual input helps maintain balance and posture.

• Extensor or stretch reflexes: Help maintain upright posture by responding to muscle stretch.

Exercise, Mobility, and Health

Types of Exercises

• Isotonic: Muscle shortens and movement occurs (e.g., walking, jogging, swimming).

• Isometric: Muscle contracts without changing length (e.g., holding a plank position).

• Isokinetic: Muscle contracts with resistance at a constant speed (e.g., using specialized exercise machines).

Example: Jogging is an isotonic exercise, not isometric.

Benefits of Exercise

• Cardiovascular System:

  • Increases heart efficiency

  • Lowers heart rate and blood pressure

  • Improves blood flow and venous return

  • Increases circulating fibrinolysin (helps prevent blood clots)

• Respiratory System:

  • Improves alveolar ventilation

  • Decreases work of breathing

  • Enhances diaphragmatic movement

• Musculoskeletal System:

  • Increases muscle strength and flexibility

  • Improves coordination

  • Reduces bone loss

  • Enhances nerve impulse transmission

• Metabolic and Gastrointestinal Systems:

  • Increases triglyceride breakdown

  • Improves gastric motility and digestion

  • Raises body heat production

  • Stimulates appetite and intestinal tone

  • Assists with weight control

Risks Related to Exercise

• Cardiac events (especially in those with pre-existing heart conditions)

• Orthopedic discomfort or injury

• Other health complications (e.g., dehydration, overexertion)

Effects of Immobility on the Body

• Cardiovascular: Increased risk of blood clots, decreased cardiac efficiency

• Respiratory: Reduced lung expansion, risk of pneumonia

• Musculoskeletal: Muscle atrophy, joint contractures, bone demineralization

• Metabolic: Decreased metabolic rate, altered nutrient metabolism

• Gastrointestinal: Constipation, decreased appetite

• Urinary: Urinary stasis, increased risk of infection

• Skin: Pressure ulcers

• Psychosocial: Depression, anxiety, decreased self-esteem

Assessment and Safe Patient Handling

Health History and Physical Assessment for Mobility

• Assess daily activity level, endurance, and exercise goals

• Identify mobility problems and health alterations

• Evaluate external factors affecting mobility

• Physical assessment includes:

  • Ease of movement

  • Gait and posture

  • Body alignment

  • Joint structure and function

  • Muscle mass, tone, and strength

  • Endurance

Safe Patient Handling and Mobility (SPHM)

• Ergonomics: Designing tasks and equipment to fit worker capabilities and prevent injury.

• Variables leading to injury:

  • Uncoordinated lifts

  • High exertion

  • Awkward/static postures

  • Manual lifting/transferring

  • Repetitive movements

  • Standing for long periods

Proper Body Mechanics

• Use correct posture and body movement to prevent injury

• Enhance coordination and endurance

• Prevent and correct posture-related problems

Equipment and Assistive Devices

• Gait belts

• Stand-assist and repositioning aids

• Lateral-assist devices

• Friction-reducing sheets

• Mechanical lateral-assist devices

• Transfer chairs

• Powered stand-assist and repositioning lifts

• Powered full-body lifts

Patient Positioning and Mobility Techniques

Common Patient Positions

• Protective positions: Used to prevent complications and promote comfort.

• Fowler’s position: Semi-sitting position (head of bed elevated 45-60 degrees).

• Supine (dorsal recumbent): Lying flat on the back.

• Side-lying (lateral): Lying on the side.

• Sims’ position: Semi-prone position, used for rectal exams and enemas.

• Prone position: Lying on the stomach.

• Oblique position: A variation of side-lying that reduces pressure on the hip (trochanter) region.

Example: The oblique position is recommended as an alternative to side-lying to reduce pressure on the trochanter.

Moving, Turning, or Transferring Patients

• Turning in bed

• Moving up in bed

• Transferring from bed to stretcher or chair

• Assisting with range-of-motion exercises (active and passive)

Physical Conditioning for Mobility

• Quadriceps and gluteal setting drills

• Push-ups (in bed or chair)

• Dangling (sitting on the edge of the bed with feet down)

Mechanical Aids for Walking

• Walker

• Cane

• Braces

• Crutches

Summary Table: Types of Exercise

Type of Exercise	Description	Example
Isotonic	Muscle shortens, movement occurs	Jogging, walking, swimming
Isometric	Muscle contracts, no movement	Plank, wall sit
Isokinetic	Muscle contracts with resistance at constant speed	Resistance training machines

Additional info:

• Proper lifting technique involves bending at the knees, keeping the back straight, and holding objects close to the body to reduce strain.

• Regular assessment and use of assistive devices can prevent injury to both patients and healthcare workers.