The impact response of the seated subject
| Autor: | Magnus Svensson, Michal Benda, H. Broman, Malcolm H. Pope, Tommy Hansson, Charlotte Ottosson |
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| Rok vydání: | 1991 |
| Předmět: |
Physics
Adult medicine.medical_specialty Lumbar Vertebrae Acoustics Attenuation Muscles Posture Spinous process Pendulum Resonance Vibration Transmissibility (vibration) Surgery medicine.anatomical_structure Amplitude medicine Humans Orthopedics and Sports Medicine Female Stress Mechanical medicine.symptom Muscle contraction Muscle Contraction |
| Zdroj: | Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 9(1) |
| ISSN: | 0736-0266 |
| Popis: | An impact method for establishing the dynamic response of the seated subject is introduced. The method employs a pendulum to apply the impact to the suspended seat. Pins are placed in the spinous process at L3. Highly reproducible results are obtained. The results were not affected by the amplitude of impact, implying a linear system. A marked peak of transmissibility is found in the 4-5 Hz range and an attenuation peak is found close to 8 Hz. Both muscle contraction and postural changes affect the dynamic response. A relaxed posture shows greater gain and attenuation peaks. A valsalva stiffens the system and reduces the effective damping. The vertical response of the body probably shows in the 5-6 Hz peak, while the rotational response is probably encompassed in the 8 Hz attenuation peak. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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