KIN 100 1st Edition Lecture 16 Ergonomics and low back pain● ■ ergonomics- workplace health, safety and efficiency.● Design■ furniture, computers etc● interactions between the workplace and people● work environment- lighting● work schedule● specific workplace issues○ industrial psychology○ mechanical engineering○ biomechanics● ergonomic principles'○ limit energy expenditure■ fidgeting from boredom etc○ limit noise exposure■ machinery■ hearing impairments○ human-machine interface○ rest periods■ how long and what should they do● Back pain in the US○ 2nd leading cause of disability○ 75-80% of people will experience LBP(lower back pain) at least once in life○ general spine anatomy■ humans have long spines■ Segments of the spine● Cervical (C1-C7)○ upper part of body● Thoracic (T1-T12)● Lumbar (L1-L5)○ lower body-low back pain● Sacral (S1-S5)■ Lumbar spine● cumulative trauma: decrease shock absorption over time● epidemiology○ age- more susceptible with age○ load- heavier load= more stress on lower back○ rate of load change-moving a heavy object quickly○ psychological- anxiety, stress, depression, obesity increasechances of LBP○ lots of research about surgery vs conservative treatment (pt)■ long term- usually same■ short term- surgery is slightly more effective, higher risk○ LBP classification■ Acute LBP● short term, gone by 6 weeks max● 85-95% of cases■ Chronic LBP● long term, >8 weeks○ joint torque (moment)■ Torque (T) = force x distance■ F(force)= load(newtons)■ d(distance)=moment arm meters)● force-joint distance■ change force->decrease torque● magnitude● distance■ carrying load● moving load away from body increases torque and force on LB● more effective to hold load close to body○ LBP myths■ you can protect your back by strengthening torso muscles■ sit ups increase back health■ bend knees, not back■ same exercise program works for everyone■ myth of core stability○ repeated "sub-failure" leads to tissue fatigue○ back belts■ not helpful■ false sense of security-people lift more than they should■ abnormal motor patterns○ bed rest vs exercise■ past-bed rest until pain is gone■ now- start light exercise asap○ Back injury prevention■ design tasks that facilitate variety■ avoid fully flexed spine■ keep external load close to trunk■ avoid lifting shortly after waking up■ maintain fitness■ provide rest breaks○ People with moderate activity are less likely to experience LBP than those with little or excessive
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