Presentation on theme: "Part II: Identifying the Risk Factors for Musculoskeletal Disorders"— Presentation transcript:
1 Part II: Identifying the Risk Factors for Musculoskeletal Disorders Workplace Ergonomics: Understanding and Preventing Musculoskeletal Disorders and InjuriesPart II:Identifying the Risk Factors forMusculoskeletal DisordersDevelopers: Margaret Nuesca and Karen Traicoff (Occupational Therapy Students)Project Advisors: Tiffany Boggis, MBA, OTR/L and Zachery Collins, MOTR/L, CEASDirector, School of Occupational Therapy: John White, Ph. D, OTR/LSpring 2010
2 Ergonomic Risk Factor Interaction Risk factors inherent in the Worker:PhysicalPsychologicalNon-work related activitiesRisk factors inherent in the Job:Work proceduresEquipmentWorkstation designRisk factors inherent in the environmentPsychosocial “climate”WorkerTask/JobEnvironmentThe goal of ergonomics is to design the job to fit the workerNOT make the worker fit the job
3 Risk Factors that lead to Musculoskeletal Disorders RepetitionForcePostureDurationContact StressesPsychosocial factors
4 RepetitionRepetition is performing the same postures or motions again and againCan be very frequent over short period of timeCan be less frequent but repeated over timeA job is considered repetitive if the basic cycle time is less than 30 seconds primarily for hand/wrist motionsExample: Typing on a keyboardA job requiring back or shoulder movements is considered repetitive with a several minute intervalExample: Lifting boxes from the floorRepetition combined with other risk factors such as awkward postures and force can increase the risk injury.Examples:Typing on a keyboard with wrist bentHolding a phone with shoulder and cheekLifting heavy material without proper body mechanics
5 ForceDefined as a strenuous physical exertion usually with heavy loads, may be performed as a push, pull or lift.Common activities contributing to excessive force:Lifting and carryingPushing and pullingReaching to pick up loadsProlonged holdingPinching or squeezingForce combined with other risk factors such as awkward postures and duration can increase the risk injury.Maximum Force Guidelines to take into consideration by Wick & McKinnis (1998):Pinch Grip max of 8 lbs (3.6 kg)Power Grip max of 25 lbs (11.3 kg)Push max of 24 lbs (11 kg)Pull max of 18 lbs (8.2 kg)Static Force Exertion max of 60 seconds
6 Posture Proper Neutral Posture consist of: Awkward Postures Spine in 3 natural curves (back straight)Arms & legs parallel to the torso (arms & shoulders down to the side, legs straight)Elbows, hips, & knees may be at 90 degrees or more (elbows bent, body sitting)Awkward PosturesAre often caused by misalignment between the user’s body/joints and the accessories and/or computer componentsOccurs when the body moves out of a neutral sitting/standing positionAwkward postures that can lead to injury are:Reaching to pick up loadsTwisting while liftingMore than 60 seconds in an awkward posture may become a risk factor, such as:Working overheadBending over to floor/groundWorking with wrist bent or typing at the computer
7 DurationDefined as maintaining a task or position for an extended timeThere are various forms of durationShort Duration: Occurring less than 1 hour a dayModerate Duration: Occurring 1-2 hours a dayLong Duration: Occurring more than 2 hours a dayExamples of duration that produce higher risks:Prolonged sitting and standing with no rest/stretch breaks increases the risk of low-back painHolding arms over head or arms/elbows extended in a fixed awkward position for a long duration becomes a risk factorSustaining a fixed task or position for long periods of time decreases blood circulation
8 Contact StressesDefined as pressure of the soft tissue and skin against any hard surfaceContact stress combined with force and repetition increases risk factorExamples:Resting wrist or forearm over theedge of the work tablesLegs lose circulation by contactwith edge of a chairUsing one’s hand as a hammer, such ascompacting items or pushing down on a staplerWorking on knees without cushionsSustaining a fixed position for long periods of time decreases blood circulation and may damage tissue or a nervedamaged ligaments leading to tendonitisdamaged median nerve leading to carpal tunnel syndrome
9 Psychosocial factors Work-related job stressors as seen in: High mental demandsWorkloads and deadlinesLow job controlPoor social supportNon work-related stressors may include:Depression and anxietySymptoms of psychological distressHome problemsThere is increasing evidence that psychosocial factors related to job and work environment play a role in the development of work-related MSDs of the UE and back.Studies have shown that psychosocial demands may produce increased muscle tension and exacerbated task-related biomechanical strain (National Institute for Occupational Safety and Health, 1997).Psychosocial demands may affect awareness and reporting of MSD symptoms, and/or perceptions of their cause.
10 Part II SummaryRisk factors that contribute to MSD’s within the workplace are:RepetitionForcePostureDurationContact StressesPsychosocialA combination of these risk factors can increase the likelihood for injury
11 ReferencesClaiborne, D. K., Powell, N. J. & Reynolds-Lynch, K. (1999). Ergonomics and cumulative trauma disorders: A handbook for occupational therapists. San Diego: Singular Publishing Group, Inc.Konz, S. & Johnson, S. (2004). Work design: Occupational ergonomics. Scottsdale, AZ: Holcomb Hathaway. National Institute for Occupational Safety and Health (1997). Musculoskeletal disorders and workplace factors: A critical review of epidemiologic evidence for work-related musculoskeletal disorders of the neck, back, upper extremity, and low back. Retrieved fromDepartment of Business and Consumer Business Oregon OSHA (no date). Introduction to Ergonomics: How to indentify, control, and reduce musculoskeletal disorders in your workplace. Retrieved fromUniversity of Oregon, Labor Education and Research Center, & Oregon Occupational Safety and Health Administration (2008). Applied Ergonomics for Long Term Care [PowerPoint slides]. Retrieved fromWick, J. & McKinnis, M. (1998). A structured ergonomics design review process. In S. Kumar (Ed.), Advances in Occupational Ergonomics and Safety (pp ). Amsterdam: IOS Press.