Physical Activity & Immobility

Musculoskeletal Physiology and Body Movement

• Skeletal System Structures:

  • Bone composition: Bones consist of a hard outer shell composed of compact bone and a porous interior known as spongy bone (containing trabeculae).

  • Total bone count: The human adult skeleton consists of $206$ bones.

  • Long bones: Include the femur and humerus.

  • Short bones: Include the phalanges and metacarpals (participate in red blood cell production).

  • Flat bones: Include the sternum and cranial bones (participate in red blood cell production).

  • Irregular bones: Include the vertebrae and tarsal bones (participate in red blood cell production).

• Cellular Bone Remodeling:

  • Osteoclasts: Specialized cells responsible for breaking down and reabsorbing old or damaged bone tissue.

  • Osteoblasts: Cells that repair, synthesize, and build new bone matrix.

• Joint Anatomy and Classifications:

  • Joint definition: The articulation site where two bones come together to facilitate movement.

  • Synarthroses: Immovable joints, such as the sutures found between cranial bones.

  • Amphiarthroses: Joints permitting limited movement, such as those between vertebrae or the pubic symphysis.

  • Diarthroses (Synovial Joints): Freely moveable joints containing a joint cavity filled with synovial fluid and lined with articular cartilage (connective tissue) to eliminate friction during movement.

• Connective Tissue Structures:

  • Ligaments: Tough, dense fibrous connective tissue bands that connect bone to bone across most moveable joints.

  • Tendons: Strong fibrous cords attaching skeletal muscle to bone.

  • Cartilage: Smooth, flexible, elastic connective tissue that acts as a cushion between joints and forms structural elements in areas such as the ears, nose, and intervertebral discs.

• Muscular System Mechanics:

  • Total mass: Muscle tissue accounts for approximately half of total human body weight.

  • Skeletal muscle: Voluntary muscle attached to bones that produces gross and fine body movements.

  • Smooth muscle: Involuntary muscle located in the walls of internal organs and hollow structures, such as the digestive tract, urinary bladder, and blood vessels.

  • Cardiac muscle: Specialized involuntary heart muscle capable of spontaneous, rhythmic contractions.

  • Point of origin: The muscle attachment site on the stationary or less moveable bone.

  • Point of insertion: The muscle attachment site on the mobile or moving bone.

  • Antagonistic muscle pairs: Muscles function in reciprocal pairs; for instance, when the biceps brachii contracts during elbow flexion, the triceps brachii relaxes.

• Motor Nervous System Regulation:

  • Autonomic nervous system: Divided into sympathetic and parasympathetic branches; regulates involuntary motor responses in cardiac muscle, smooth muscle, and glands.

  • Somatic nervous system: Controls voluntary movements of skeletal muscles mediated by conscious neural decisions.

  • Reflex mechanisms: Involuntary, automatic motor responses triggered by sensory stimuli, such as the knee-jerk (patellar) or corneal reflexes.

  • Afferent feedback loop: Muscle contraction—whether voluntary or reflex-driven—stimulates sensory afferent nerves that relay signals back to the cerebral cortex and cerebellum for continuous motor control and coordination.

Body Mechanics and Injury Prevention

• Four Core Components of Body Movement:

  • Alignment (Posture): Maintenance of proper spinal curves ensures that muscles, joints, and ligaments operate at maximum mechanical efficiency, supporting nervous system function and structural health.

- Cervical spine: $7$ cervical vertebrae forming the cervical curve.
- Thoracic spine: $12$ thoracic vertebrae forming the thoracic curve.
- Lumbar spine: $5$ lumbar vertebrae forming the lumbar curve.
- Sacrum: $5$ fused sacral vertebrae forming the sacral curve.
- Coccyx: $4$ fused coccygeal vertebrae.

• Balance:

  • Line of gravity: An imaginary vertical line extending from the top of the head down through the center of gravity to the base of support.

  • Center of gravity: The focal point where body mass is centered and evenly distributed.

  • Base of support: The geographic surface beneath an individual that supports their weight (e.g., the feet).

• Coordination: Controlled movement depends on integrated communication between the nervous system and musculoskeletal system.

  • Cerebral cortex: Regulates deliberate, voluntary motor initiation.

  • Cerebellum: Controls fine motor balance, posture, and proprioception (awareness of spatial body position and movement).

  • Basal ganglia: Subcortical structures deep within the cerebrum that assist in modulating motor control and coordination.

• Joint Mobility: Enables essential activities like sitting, standing, bending, and ambulating.

  • Range of Motion (ROM): The full architectural distance a joint can move.

  • Active Range of Motion (AROM): Joint movement accomplished independently by the individual without assistance.

  • Passive Range of Motion (PROM): Joint movement achieved when an external force or caregiver moves the joint without patient muscular effort.

  • Principles for Injury Avoidance:

• Maintain correct body alignment at all times.

• Establish a wide base of support by spreading feet shoulder-width apart.

• Avoid simultaneous bending and spinal twisting.

• Flex at the knees and hips (squat) rather than bending from the waist when lifting.

• Hold heavy objects close to the body's center of gravity.

• Adjust working surfaces (e.g., raising hospital beds) to an appropriate waist-level height.

• Push, pull, or roll heavy objects instead of lifting them whenever possible.

• Request additional staff assistance before attempting heavy lifting or transfers.

• Protect the upper back, lower back, arms, and legs from acute force strain.

Exercise Physiology and Fitness Planning

• Exercise Classifications:

  • Isometric exercise: Muscle contraction occurs without change in muscle length or joint movement (e.g., pushing against a solid wall).

  • Isotonic exercise: Muscle contraction produces joint movement and muscle shortening (e.g., weight lifting, walking).

  • Isokinetic exercise: Uses specialized constant-speed mechanical devices to provide variable resistance throughout a joint's full range of motion.

  • Aerobic exercise: Uses large muscle groups in continuous, rhythmic activity that relies on metabolic energy pathways using oxygen ($O_2$), raising heart and respiratory rates to stress the cardiovascular system.

  • Anaerobic exercise: High-intensity, short-duration exertion where tissue oxygen demand exceeds the available oxygen supply delivered by the cardiovascular system.

• Designing and Evaluating Fitness Programs:

  • Program individualization: Must match patient-specific physical limitations, underlying medical conditions, and lifestyle preferences.

  • Dosing variables:

  • Duration: The total time dedicated to an exercise session.

  • Frequency: How many times per week exercise is performed.

  • Key functional parameters:

  • Flexibility: Warm-up stretching routine to prepare muscle tissue.

  • Resistance training: Structured activities targeting muscle strength and endurance.

  • Aerobic conditioning: Parameters established by monitoring cardiovascular intensity and activity duration.

  • Adherence: Utilization of motivational incentives and structural support systems.

  • Lifespan considerations: Regular physical activity for middle-aged and older adults is critical for maintaining independence, preserving cardiorespiratory health, and extending longevity ("Move more and sit less!").

• Health Benefits of Regular Physical Activity:

  • Decreases morbidity and mortality risks associated with:

  • Coronary heart disease and stroke

  • Type 2 diabetes mellitus

  • Essential hypertension (HTN) and hyperlipidemia

  • Metabolic syndrome

  • Breast and colon cancers

  • Clinical obesity

  • Major depressive disorder

  • All-cause mortality

• Exercise-Related Health Risks:

  • Cardiac risk: Anxiety regarding the potential triggering of acute cardiovascular events.

  • Musculoskeletal trauma: High-impact forces or rapid escalation from a sedentary routine can cause tissue tears, sprains, or strains. Mitigated by gradual workload progression and progressive resistance training.

  • Dehydration: Fluid deficits resulting from prolonged exertion or concurrent diuretic therapy.

  • Thermoregulatory imbalances:

  • Hyperthermia: Inability to dissipate heat while exercising in hot climates, escalating fluid loss.

  • Heat exhaustion: A severe condition marked by light-headedness, nausea, headache, profound fatigue, impaired concentration, muscle cramps in the legs and abdomen, elevated core temperature, and cold, clammy skin.

  • Hypothermia: Core body temperature collapse due to cold exposure without protective gear or prolonged cold-water swimming; manifests with fatigue, mental confusion, and loss of motor coordination.

Factors Influencing Mobility and Activity

• Life Stage and Age:

  • Older adults represent the statistically least physically active age demographic, though they often engage in structured low-impact fitness programs rather than competitive sports.

• Nutritional Status:

  • Obesity: Increases workload on the cardiovascular system, restricts motion, and causes accelerated mechanical joint wear.

  • Chronic illness: Leads to muscle wasting (cachexia), severe fatigue, sarcopenia, and compromised postural balance.

• Lifestyle Choices and Environment:

  • Sedentary habits are reinforced by occupational or recreational screen use.

  • Environmental barriers include adverse weather, elevated air pollution, high neighborhood crime rates, lack of sidewalks, and absence of bicycle paths.

  • Socioeconomic status: Financial limitations and poor social support networks restrict access to exercise facilities.

• Congenital and Developmental Conditions:

  • Syndactylism: Congenital webbed attachment between adjacent fingers or toes.

  • Congenital hip dysplasia: Structural instability of the acetabulofemoral joint.

  • Clubfoot (talipes equinovarus): Congenital foot deformity compromising gait.

  • Scoliosis: Lateral spinal curvature altering center of gravity and mechanics.

• Bone Metabolism and Integrity Disorders:

  • Osteogenesis imperfecta: Genetic connective tissue disease producing extremely brittle bones prone to spontaneous fractures.

  • Achondroplasia: Genetic condition resulting in dwarfism due to premature ossification of epiphyseal growth plates.

  • Paget's disease: Chronic metabolic bone disease marked by excessive osteoclast activity and chaotic bone remodeling.

  • Vitamin D and Calcium ($Ca^{2+}$) deficiencies: Imbalances that weaken bone mineralization, causing porous bones, structural deformities, and pathological fractures.

  • Osteoporosis: Progressive reduction in bone mass and density occurring after age $30$, accelerating sharply in postmenopausal women. Major causes include advancing age, tobacco use, inadequate intake of $Ca^{2+}$ and Vitamin D, excessive alcohol consumption, and chronic immobility.

  • Osteomyelitis: Severe bacterial bone infection occurring after open trauma or surgery, where pathogens proliferate within bone channels.

  • Bone tumors: Benign or malignant neoplasms that weaken bone integrity, cause severe pain, and limit mobility.

  • Acute trauma: Includes mechanical fractures, joint sprains (stretching or tearing of ligaments), muscle strains (overexertion of muscle tissue), and structural tendon tears (e.g., rotator cuff, knee ligaments, Achilles tendon).

• Joint and Neurological Disorders:

  • Osteoarthritis: Non-inflammatory degenerative joint disease characterized by progressive loss of articular cartilage, producing pain and joint stiffness.

  • Rheumatoid arthritis: Systemic autoimmune disorder causing chronic synovial inflammation, joint erosion, and systemic disability.

  • Ankylosing spondylitis: Chronic inflammatory disease leading to progressive fusion of the spine and sacroiliac joints.

  • Gout: Inflammatory arthritis caused by hyperuricemia, leading to monosodium urate crystal deposition in synovial fluid. Causes acute pain, warmth, and erythema, commonly in the big toe, foot, wrist, or ankle.

  • Cerebrovascular accident (CVA/Stroke): Ischemia or hemorrhage in brain tissue resulting in motor deficits, hemiplegia, or paralysis.

  • Central nervous system trauma: Traumatic brain injuries or spinal cord injuries interrupting motor pathways.

  • Multiple Sclerosis (MS): Demyelinating central nervous system disease that disrupts nerve impulse transmission.

  • Myasthenia Gravis: Autoimmune disease affecting neuromuscular junction acetylcholine receptors, causing profound muscular weakness.

• Systemic Disease and Fatigue:

  • Pulmonary disorders: Chronic Obstructive Pulmonary Disease (COPD), asthma, and pneumonia impair gas exchange and severely restrict exertion tolerance.

  • Cardiovascular disorders: Heart failure and peripheral vascular disease impair systemic oxygen delivery.

  • Acute fatigue: Transient reduction in energy resulting from infectious illnesses such as influenza.

  • Chronic fatigue: Persistent exhaustion linked to underlying systemic pathology, including severe anemia, anorexia, malignancy, or major depression.

  • Therapeutic bedrest: Prescribed immobility designed to reduce systemic workload following major surgery, acute medical crises, or severe chronic illness.

Systemic Hazards of Immobility

• Multisystem Complications of Inactivity:

  • Musculoskeletal: Rapid muscle atrophy, loss of muscle strength, joint contractures, foot drop (plantar flexion contracture due to prolonged improper positioning), and bone demineralization leading to disuse osteoporosis.

  • Renal and Metabolic: Development of renal calculi (kidney stones) secondary to hypercalciuria from bone resorption, hypercalcemia, and metabolic slowing.

  • Gastrointestinal: Systemic malnutrition, decreased intestinal peristalsis, and severe constipation.

  • Respiratory: Stasis of pulmonary secretions, hypostatic pneumonia, and atelectasis (alveolar collapse).

  • Cardiovascular: Deep vein thrombosis (DVT) formation, pulmonary embolism, orthostatic hypotension, and increased cardiac workload.

  • Integumentary: Ischemic tissue breakdown and development of pressure injuries over bony prominences.

  • Neurological and Psychosocial: Acute delirium, disorientation, clinical depression, cognitive decline, functional decline, and pervasive feelings of hopelessness.

Nursing Assessment and Interventions

• Nursing Process Implementation:

  • Assessment: Gather comprehensive baseline physical data, including current activity level, lifestyle, external barriers, and subjective complaints.

  • Focused Assessment: Evaluate gait dynamics, balance stability, activity-induced pain, physical skeletal deformities, and fall history.

  • Diagnoses: Classify client conditions using NANDA-I categories such as Activity Intolerance or Risk for Activity Intolerance secondary to physiological or structural etiologies.

  • Planning: Formulate measurable, patient-centered outcomes prioritizing energy maintenance, activity tolerance, fatigue mitigation, rest, and sleep.

  • Interventions: Implement clinical protocols including body mechanics instruction, structured exercise, active/passive ROM exercises, scheduled turning routines, and assisted transfers.

  • Evaluation: Measure outcome progress against target goals, analyze functional functional gains, and modify the plan of care as clinical status changes.

• Strategies to Encourage Physical Activity:

  • Tailor discussions to highlight benefits meaningful to the individual.

  • Incorporate the patient's preferred recreational activities.

  • Collaborate to set realistic, incremental, short-term targets.

  • Provide a range of activity choices to prevent monotony.

  • Acknowledge and celebrate all functional achievements.

  • Identify environmental or physical barriers and develop targeted solutions.

• Patient Positioning Equipment and Techniques:

  • Support equipment: Use pillows, foam wedges, bed side-rails, overhead trapeze bars, footboards, sandbags, trochanter rolls, and splints.

• Standard positions:

  • Fowler's position: Semi-sitting position with the head of the bed elevated between $45^\circ$ and $60^\circ$.

  • Lateral position: Side-lying alignment with body weight supported on the hip and shoulder.

  • Prone position: Patient lies flat on the abdomen with head turned to one side.

  • Sims' position: Semi-prone posture where the upper knee and hip are flexed, promoting oral fluid drainage.

  • Supine position: Patient lies flat on their back with head and shoulders supported.

  • Moving and Transfer Protocols:

• Bed repositioning: Use a friction-reducing draw sheet or slide sheet. Assess patient weight, cognitive ability, and physical status to determine whether $2$ or $4$ staff members are required.

• Logrolling: A multi-caregiver technique ($2$ or more staff) that rotates the patient's entire body as a single unit, keeping the spine strictly aligned.

• Mechanical transfer equipment: Utilize slide boards, transfer boards, friction-reducing slide sheets, standing assistance devices, and powered mechanical sling lifts (e.g., EZ Lift) to prevent caregiver back injury.

• Ambulation Assistance and Safety:

  • Preparatory conditioning: Perform pre-ambulation range-of-motion and muscle-strengthening exercises.

  • Interprofessional referral: Obtain orders for Physical Therapy (PT) screening or full evaluation. Coordinate with PT and Occupational Therapy (OT) for assistive device fitting.

  • Mobility devices: Gait belts, canes, walkers, wheelchairs, and crutches (used selectively in long-term care environments).

• Orthostatic hypotension protocols:

  • Apply antiembolism stockings (TED hose) to prevent lower extremity venous pooling.

  • Utilize abdominal binders to maintain venous return.

  • Administer prescribed vasopressor medications (e.g., midodrine) as ordered.

  • Execute slow, staged position changes (e.g., dangling legs at the bedside) to allow baroreceptor adaptation.

• Environmental safety checks:

  • Assess client balance and readiness before standing.

  • Ensure adequate staff assistance and physical devices are present.

  • Clear walking pathways of all tripping hazards, liquid spills, or structural obstructions.

  • Fit the patient with proper supportive, non-skid footwear.