Mobility and Musculoskeletal Function
Defining Normal Mobility and Independence
Mobility Definition: Mobility is defined as the ability to move freely within the environment. It is considered fundamental to an individual's daily functioning.
Societal Significance: In a highly mobile society, any problems that affect an individual's mobility are viewed as especially significant.
Defining Independence: Independence is usually defined by a person\'s ability to perform specific activities:
Activities of Daily Living (ADLs).
Job-related activities.
Role-related activities: These include roles such as being a parent or a spouse.
Limitations: Limitations in a person’s ability to move can negatively affect all areas of independence.
Psychological Implications of Mobility
Communication: Changes in mobility have psychological implications, particularly regarding communication.
Nonverbal Communication: Facial expressions and gestures are significant components of nonverbal communication.
Eye Level Interaction: Talking with someone at eye level promotes a sense of equality.
Psychological Disadvantage: A person who must look up at others from a chair or bed may feel they are at a psychological disadvantage.
Tension Diffusion: Movement serves as a significant method for diffusing negative feelings and tension.
Stress Relief: Jogging and other forms of exercise help many people relieve stress and anxiety.
Feeling of Control: The ability to leave uncomfortable or dangerous situations provides a feeling of control.
Self-Image and Sickness:
People confined to bed usually perceive themselves as "sick" and may feel less capable of participating in their own recovery process.
Disabilities affecting mobility, such as an amputation or a musculoskeletal defect, may significantly alter a person’s self-image.
Association with Health: Most people associate mobility with health.
The Mobility Continuum
Mobility is viewed along a continuum ranging from full mobility to immobility.
Full Mobility: Occurs when a person has no physical or psychological factors limiting their movement.
Immobility: Occurs when a person cannot move their entire body or a specific body part.
Movement Along the Continuum:
Temporary Changes: For example, the placement of a cast to repair a fracture creates a temporary change in mobility.
Progressive Disability: Certain conditions, such as muscular dystrophy or severe crippling rheumatoid arthritis, cause a progressive decline in mobility.
Permanent Changes: These occur when normal body movement cannot be restored, such as in spinal cord injuries resulting in paralysis or strokes causing weakness/paralysis on one side of the body.
Rehabilitation: This is the key process for restoring a person with certain disabilities to their optimal level of mobility. Nurses play a significant role in this process.
The Musculoskeletal System: Structure and Components
Bones:
Function: Bones act as a framework for the attachment of muscles, tendons, and ligaments. They facilitate movement, protect vital organs, store and regulate calcium and phosphate, and form blood cells.
Structural Efficiency: Bone structure is designed for minimum weight and maximum structural strength.
Bone Tissue Types:
Woven Bone: Characterized by rapid growth (infancy); found in adults where ligaments and tendons insert into bones.
Lamellar Bone: Mature bone consisting of highly organized mineralized plates.
Classification by Shape: There are bones in the body categorised as:
Long bones: Arms and legs.
Short bones: Tarsals and carpals.
Flat bones: Cranium.
Irregular bones: Vertebral.
Long Bone Anatomy: Components include the diaphysis (shaft) and epiphyses (ends). Most bone is covered by the periosteum, which contains nerves and blood vessels. The outer portion is dense, compact bone, while the center marrow cavity holds blood-forming cells.
Muscles:
Composition: Skeletal muscles are composed of striated, long muscle fibers in parallel alignment.
Function: Fibers allow muscles to contract (shorten) or extend (lengthen).
Mechanism of Contraction: Contraction happens when overlapping striated fibers slide toward each other, shortening the muscle and increasing strength.
Neuromuscular Process:
An action potential (electrical charge) moves along a nerve across the neuromuscular junction.
Neurotransmitters (e.g., ) permit the transmission of impulses.
Calcium is released into the sarcoplasmic reticulum (storage and release site).
Energy is derived from the metabolism of food, specifically fats and carbohydrates.
Innervation: Fibers are innervated by motor neurons from the anterior horn of the spinal cord.
Motor Unit: All muscle fibers connected to a single motor nerve.
Hypertrophy vs. Atrophy: Humans have a fixed number of muscle cells from birth. Muscle size depends on work. Hypertrophy is the increase in muscle diameter and strength due to forceful activity. Atrophy is the decrease in size and strength due to disuse (lack of exercise, aging, bed rest, or immobilizing devices).
Joints:
Fibrous: Non-moving (e.g., cranial joints).
Cartilaginous: Minimal movement (e.g., costochondral joints).
Synovial: Moveable joints (e.g., extremities). These are lined with synovial tissue, which has a rich blood supply and produces synovial fluid for lubrication.
Connective Tissues:
Ligaments: Connect bone to bone; elastic to allow movement.
Tendons: Connect muscle to bone; move the bone when the muscle contracts.
Normal Physiologic Function and Coordination
Alignment and Posture:
Requires proper alignment of bones, muscles, and joints, and a stable center of gravity.
Alignment Status: Achieved when joints/muscles are not at extremes of extension/flexion or under unusual stress.
Line of Gravity: Starts at the top of the head and bisects the shoulders, trunk, weight-bearing joints, and base of support; runs slightly anterior to the sacrum.
Age-Related Changes: In older people, the lumbar spine flattens, and the head/upper spine tilt forward, causing the head to fall forward from the line of gravity.
Balance:
Reticular Formation: A brain stem neural network that integrates input for balance.
Reflexive Response: If falling to one side, extensor muscles on that side stiffen while the opposite side relaxes.
Vestibular Apparatus (Ear): Primary source of equilibrium. Includes the cochlear duct, semicircular canals, and chambers (utricle and saccule). Tiny hair cells in these structures bend during head movement, sending signals to the vestibular nerve.
Coordinated Movement Control:
Cerebellum: Coordinates motor activities, steady posture, rapid automatic adjustments, and refines learned movement patterns by comparing motor commands with proprioceptive information (position sense).
Cerebral Cortex: Initiates voluntary motor activity.
Basal Ganglia: Maintains posture.
Nervous Pathways:
Pyramidal Tract: Direct corticospinal pathway for voluntary movement transmission.
Extrapyramidal Tract: Indirect pathway that inhibits impulses to ensure movements are smooth and coordinated.
Principles of Body Mechanics
Definition: Body mechanics is the coordinated effort of using alignment, posture, and balance to perform activities such as lifting, bending, and moving.
Components:
Center of Gravity: Located in the pelvis, slightly anterior to the sacrum.
Stability: A broad base of support (feet further apart) and flexing hip/knee joints lowers the center of gravity and increases stability.
Vertical Alignment: Keeping the spine vertical and body weight close to the center of gravity.
Leverage: Flexors in the legs are the largest and strongest muscles and are used for leverage.
The Four Rules of Body Mechanics for Nurses:
Assess and Plan: Assess the situation, remove obstacles (equipment, cords), and handle medical lines (IVs, catheters). Use a "one, two, three" count for coordination.
Use Large Muscle Groups: Use leg muscles rather than the back. Keep the back straight, elbows slightly flexed, and bend at the hips and knees. Avoid twisting or diagonal movement.
Work at Appropriate Height: Raise the bed to the nurse's center of gravity (between hips and waist). Lower side rails to avoid reaching. Keep bed and stretcher at the same height during transfers.
Use Mechanical Assistance: Use lifts when the patient cannot assist or if safety is uncertain.
Stand-up Lifts: Patient bears some weight and follows commands.
Overhead Trapezes: For patients with upper body strength.
Floor/Ceiling Lifts: For non-weight-bearing patients.
Friction-Reducers: Draw sheets or slippery "turn sheets" used by or more nurses.
Exercise: Types and Benefits
Classifications by Energy Source:
Aerobic: Requires oxygen; vigorous/continuous movement (walking, running, cycling) that promotes cardiovascular conditioning.
Anaerobic: Occurs when muscles cannot extract enough oxygen; used in endurance training for short durations.
Classifications by Muscle Tension:
Isotonic: Dynamic exercise with constant tension and active movement (walking, ADLs).
Isometric: Static exercise where a muscle is tensed but held stationary (strength training with weights).
Benefits of Exercise:
Physiologic: Strengthens muscles, increases endurance, promotes joint mobility, increases lung capacity, decreases pulse/blood pressure, reduces atherosclerosis risk, prevents constipation, and improves sleep.
Psychological: Increases circulating endorphins, releases tension/stress, and improves self-image/physical appearance.
Characteristics of Normal Movement
Range of Motion (ROM):
Active ROM: The person initiates and performs the movement themselves.
Passive ROM: Someone else (e.g., physical therapist) initiates and carries out the movement for the patient.
Normal Gait:
Definition: The style and character of a person’s walk.
Stance Phase (Events): Heel strike, midstance, push-off.
Swing Phase (Events): Acceleration, swing through, deceleration.
Mechanism: Initiated by a forward tilt; weight rolls off the ball/toes of one foot to the heel of the opposite foot.
Lifespan Considerations
Newborns and Infants:
Movements are random and reflexive.
Reflexes: Survival (rooting, sucking), Subcortical (Moro, startle, tonic neck, Babinski), Protective (gag, blink, withdrawal), and Stepping response.
Developmental Order: Proceeds proximal to distal and head-to-toe (cephalocaudal). Sequence: head control → rolling → crawling → pulling up → standing → walking.
Milestones: Act as a yardstick for evaluation; order is fixed, but exact timing varies.
Toddlers and Preschoolers:
Master walking after the birthday with a wide stance/unsteady gait.
Gross motor skills: Jumping, climbing, riding tricycles, dancing.
Fine motor skills: Scribbling, buttoning, brushing teeth, puzzles.
Children and Adolescents:
Physical growth slows between ages and .
Adolescence is marked by rapid physical/sexual development.
"Gangly" appearance due to uneven growth in body parts can affect body image.
Adults and Older Adults:
Young Adults ( to years): Mobility changes usually via trauma or repetitive stress (e.g., Carpal Tunnel Syndrome).
Middle Age ( to years): Decreased muscle tone and bone density. Joints lose flexibility.
Older Adults: High risk of fractures due to osteoporosis. Postural changes include flatter lumbar spine and forward-leaning crouch. Gait becomes wide-based, short-stepped, and shuffling. Osteoarthritis in hips/knees often requires joint replacement.
Fear of Falling: Can lead to voluntary activity restriction, resulting in muscle atrophy or deconditioning.
Cultural Considerations
Attitudes toward exercise are shaped by family, culture, and job.
Environment: People in agricultural communities have different activity levels than those in industrialized areas.
Technology: May influence participation in sports.
Gender Norms: Vary across cultures and affect physical activity levels.
Cultural Learning: Children internalize the norms of their culture, which determines their adult activity levels.