Ergonomics

• Haptic perception


  A type of centrally mediated sensation characterized by identifying and perceiving object features achieved by active exploration of the object
• Hypersensitivity


  A response to sensory information in which ordinary stimuli produce exaggerated or unpleasant sensations
• Hyperesthesia


  A type of hypersensitivity characterized by heightened sensitivity to tactile stimuli
• Peripherally mediated sensation


  Sensation controlled primarily by sensory receptors in the skin, such as light touch
• Quantitative sensory testing (QST)


  A type of assessment; the standardized application of a stimulus followed by an interpretation of the patient's response in quantitative measures, such as percentage of correct responses
• Sensibility


  A person's sensitivity to sensory stimulation; considered a patient factor in occupational therapy
• Sensory reeducation


  A type of sensory intervention in which therapists guide the process of reteaching the brain how to feel and interpret sensory stimulation
• neuro and physiological basis of sensory function


  • sensory sys operates via skin, muscles, and joint receptors—each specialized to receive various types of stimulation (e.g., touch, temperature, or pain)
  • There is redundancy in the sensory receptor system. Each sensory neuron, and the skin area it serves, overlaps with other sensory receptor areas
  • A single stimulus then activates several adjacent sensory receptors
• With brain injury: Perception of fine touch and proprioception are most affected, Temperature sensation is less affected, and Pain sensibility is least affected
• Complete spinal injury


  All motor and sensory functions below the lesion are lost—no preservation of function at the sacral levels
• Incomplete spinal injury


  Some degree of sensory sparing has occurred
• ASIA motor scores (quadriceps and gastrocnemius/soleus muscles), and light touch scores for the L3 and S1 dermatomes accurately discriminate between potential walkers and nonwalkers after spinal injury
• Findings of discomfort with touch (hypersensitivity)


  Suggest need for desensitization intervention
• Sensory reeducation interventions


  Provided for patients with some sensation and potential for more
• Compensation strategies


  • Using vision to compensate for lack of sensation
  • Use the sensate hand for tasks requiring temperature or pain detection
  • Checking the insensate body part for abrasions, cuts, or burns
  • Wearing protective garments to prevent injury
  • Modifying the task to avoid injury
• Desensitization


  Used when sensory evaluation reveals area of hypersensitivity (stimuli produces exaggerated sensations)
• Hypersensitivity


  • Allodynia—perception of pain in response to nonpainful stimulus
  • Hyperesthesia— heightened sensitivity to tactile stimuli
• Desensitization programs include repetitive stimulation of hypersensitive skin with items that provide a variety of sensory experiences
• Musculoskeletal Discomforts and Disorders (MSDs)


  Soft-tissue injuries that may be caused by factors such as sustained exposure to repetitive motion, force, and awkward positions
• Ergonomics


  Focuses on injury prevention through evaluation and design of workstations and the physical environment, including postures, manual tasks, and repetitive movements
• Ergonomic equipment


  • Desktop riser
  • Footrest
  • Ergonomic keyboard
  • Keyboard drawer/tray
  • Lap desk
  • Laptop/monitor stand
  • Lumbar Pillow/Lumbar Support
  • Mice (Trackball Mouse Vertical Mouse)
  • Seat cushion
  • Wrist rest
• Phone use risk factors for MSDs


  Static hold, sustained grip, repetitive movements from typing, awkward postures, eye strain
• Helpful tips for phone use


  • Increase font size
  • Bring phone up to eye-level
  • Switch between right and left hand grip
  • Use speech-to-text or word prediction functions
• Job Demands Analysis (JDA)


  Defines the actual demands of the job, while ergonomic evaluations and hazard assessment focus more on the work practice and the risk for injury secondary to postural or manual material-handling extremes or excesses
• 3 COMPONENTS OF JOB ANALYSIS

  • WORKER
  • WORK
  • WORKSITE
• WORKER


  • Gender variables
  • Age variables: Musculoskeletal system; Cardio respiratory system, neurological-sensory
  • Anthropometric data
  • Skill level
  • Preexisting conditions
  • Conclusions
• WORK


  • Forces
  • Angles
  • Speed
  • Repetitions
  • Rest breaks
  • Stress level
  • Boredom level
• WORKSITE


  • Workstation: work area, seated, standing, kneeling
  • Objects of work: materials to be handled, objects to be used/manipulated, controls, tools, people
  • Environment: lighting, temperature, noise, IAQ (Indoor air quality), other people
• Manual materials handling (MMH)


  Any process in which the human operator is asked or required to lift, lower, push, pull, carry or perform any other similar task in which an object is moved through space solely under the power of the human operator
• MMH involves any handling of a product, whether it is a pencil or a 70-pound piece of electronics equipment, not just objects that are perceived to be "heavy"
• MMH is not relegated solely to heavy manufacturing environments; it includes jobs in an office where a person has to lift a 1-pound component and jobs in heavy industry where a person must lift a 55-pound object
• Functional Capacity Evaluation (FCE)


  A systematic method of measuring an individual's ability to perform meaningful tasks on a safe and dependable basis
• Uses of FCE


  • Set goals for rehabilitation and readiness for return to work
  • Assess residual work capacity
  • Determine disability status
  • Screen for physical compatibility before hiring a new employee and case closure
• Work hardening


  Formal, multidisciplinary programs for rehabilitating the injured worker
• Work conditioning


  Physical conditioning alone, which covers strength, aerobic fitness, flexibility, coordination, and endurance and generally involves a single discipline
• Worksite evaluations


  On-the-job assessments to determine if an individual can return to work after onset of a disability or whether a person can benefit from reasonable accommodations to maintain employment
• OTs and ergonomics


  • Maximizing occupational performance, injury prevention, promoting health and safety
• Ergonomics


  The science of matching the job to the worker and the product to the user
• Ergonomics fundamentals


  • Functional requirements – at work/home
  • Who are the users?
  • What do workers do?
  • How do people perform their job?
  • Where do workers engage in tasks?
  • Why do workers do what they do in the way that they do it?
• OSHA


  Occupational Safety and Health Act, a regulatory agency in the U.S. Department of Labor responsible for developing and enforcing workplace safety and health regulations