Critical analysis of the report Case Study Example | Topics and Well Written Essays - 1000 words

Critical analysis of the report - Case Study Example 2. The research conducted (and what type of study) An ergonomic study was conducted by National Institute for Occupational Safety and Health (NIOSH) on the rangers of Yellow Stone Park. Several tests were used such as the Rhythmic Test, Tremor Test, and the Vibroactile Test, to determine the reason why the rangers are experiencing musculoskeletal disorders and to find a way to prevent this kind of disorder. The first test used was the Rhythmic test. This test is used to determine the reaction time and coordination on the right and left hands. The rhythmic tests required the participants to tap a circular pad (4–inch diameter) in time with a steady metronome beat (1.0 Hertz [Hz] slow test, 2.5 Hz fast test), either alternating palm side of hand to back of hand (supination/pronation) or tapping with the index finger. At the end of the test administration a numerical coordination index is calculated, which can be compared to the normal coordination index (CI) range provided with the test battery documentation (NIOSH Health Hazard Evaluation Report, Yellow Stone Park, 2001). With this data, the reaction time and hand coordination of the rangers can be easily compared to the normal reaction time index. The difference will determine the effect of the vibrations experienced while riding a snowmobile on hand coordination. The second test used was the Tremor Test. This test used the Tremor 3.0 software for data analysis. The data collected were: (1) Tremor intensity, often called amplitude or vibration power, calculated as the root–mean–square (RMS), measured in meters per second per second (m/s2) of acceleration in the 0.9 to 15 Hz band during the 8–second test; (2) Center frequency, which is the average frequency of acceleration in the test band, so that 50% of the energy that drives the tremor is produced at frequencies above the center frequency and 50% is produced below; (3) Tremor Index, calculated for each hand from five parameters (e. g., tremor intensity, center frequency, standard deviation of the center frequency, harmonic index, and standard deviation of the harmonic index.); and (4) Combined index for both hands (NIOSH Health Hazard Evaluation Report, Yellow Stone Park, 2001). This test measures the vibrations experienced by the rangers in riding the snowmobiles and the intensity of the vibration that will likely cause the musculoskeletal disorder. The third test used is the Vibroactile Sensitivity test. This test was selected to determine the effect of the hand–arm vibration produced by snowmobiles on vibration perception thresholds. The test device used was the Bruel & Kj?r Model 96–27 Vibrometry System. This fully automated system produces a mechanical stimulus (sinusoidal vibration) at a chosen frequency to the pulp of a finger tip; the participant indicates perception of the vibration by means of a hand–held button similar to that used in a hearing test. The software was configured to test vibration at four frequencies: 31.5 Hz, 125 Hz, 250 Hz, and 500 Hz. Participants placed their right arm on an ascending armrest with the palm lying open on a circular pad, allowing the fingers to hang freely above the vibrating post. The test finger was then placed on the vibrating post with the finger slightly curved and resting lightly on the post. Participants controlled the intensity of vibration with the hand–held button, tracking back and forth between levels of stimulus perception and