Chairless Chair Exoskeleton. Work-physiological-biomechanical Analysis of the Lower Extremities
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 46
- 试验地点
- 2
- 主要终点
- Muscle Activity of the Lower Back (M. Erector Spinae Lumbalis)
研究概览
简要总结
Standing work is associated with increased risks of venous and musculoskeletal disorders; particularly low back pain is commonly reported in prolonged standing work. In manufacturing work, workstations often do not allow standing aids due to insufficient functional and spatial conditions. In 2014, the car manufacturer Audi introduced the lower leg exoskeleton developed by Noonee to their employees working in the factories. This exoskeleton, the 'Chairless Chair' has the advantage that standing work can be performed while technically sitting on this device. The exoskeleton offers the potential for reduced awkward body postures, but it is unclear which physiological and biomechanical loads are influenced and how. This proposal provides a study design evaluating the 'Chairless Chair' in a laboratory setting, by testing its effectiveness in terms of physiological and biomechanical parameters. It is suggested to compare different assembly tasks while wearing the exoskeleton, compared with not wearing the exoskeleton. The 'Chairless Chair' is developed in one size only, which is why we propose to include participants of different body height, which will enable us to investigate whether body height influences the effectiveness of wearing the device.
详细描述
Each participant was exposed to all experimental conditions, which were the following:
- Standing without the exoskeleton
- Sitting with the exoskeleton
For both experimental conditions, the working height was adjusted to the individual to become optimal. The working distance to the simulated assembly tasks was also adjusted to the individual to become optimal. Both the working height and distance were based on textual guidelines provided in DIN EN ISO 14738:2009-07.
Each work cycle consisted of assembling and disassembling the following three tasks:
- Screwing
- Clip fitting
- Cable mounting
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Age: between 18 and 40 years old;
- •Gender: male;
- •Voluntary informed consent (oral and written) is obligatory for study participation.
排除标准
- •Age: <18 and >40 years old;
- •Gender: female;
- •People under the influence of intoxicants, analgesics, or muscle relaxants;
- •Alcohol abuse;
- •People with cardiovascular diseases;
- •People with a heart pacemaker;
- •People with a disability who, due to their restriction at a workplace of this kind, will not be able to participate;
- •People with Diabetes Mellitus;
- •People with severe muscle contractions of the lower extremities, back or arms;
- •People with acute ailments or pain;
- •People who are unable to complete the examination program due to language or cognitive obstacles;
- •Depending on the degree of severity, people with diseases of the veins and joints of the lower extremities, spine, muscle disorders, symptomatic neurological-psychiatric diseases, acute pain syndromes, maladies or other current diseases.
结局指标
主要结局
Muscle Activity of the Lower Back (M. Erector Spinae Lumbalis)
时间窗: 10 minutes of 2 hours
Indicator for the muscular load in the lower back (M. erector spinae lumbalis) that may change when wearing the passive exoskeleton. The muscle activity was recorded using bipolar surface electromyography, during which two electrodes are placed on the muscle belly. The absolute value of muscle activity recordings is in microvolt, but since this is difficult to interpret, we have normalized this to a reference voluntary contraction that was executed by each participant prior to the experiment. The unit of measure for normalized muscle activity therefore is a percentage, i.e. a percentage of the electrical activity during the reference voluntary contraction \[%RVE\].
Center of Pressure
时间窗: 10 minutes of 2 hours
Indicator for the balance of the study participants. This outcome was measured using a force plate, in which the anteroposterior and mediolateral directions of the center of pressure are recorded. The center of pressure is a visual projection of the center of mass of the participant. For the anteroposterior direction of the center of pressure, a positive value \[mm\] represents the anterior direction and a negative value \[mm\] represents the posterior direction. For the mediolateral direction of the center of pressure, a positive value \[mm\] represents the right-lateral direction and a negative value \[mm\] represents the left-lateral direction. For this outcome, we recorded the anteroposterior direction of the center of pressure. The outcome is in mm, where neg. reflects the posterior direction and pos. the anterior direction.
次要结局
- Back Posture: Upper Back Forward Flexion Angle With Respect to the Perpendicular (Earth)(10 minutes of 2 hours)
- Subjective Feeling of Overall Discomfort(10 minutes of 2 hours)
- Participant Evaluation(2 hours)
研究者
Dr. Tessy Luger
Principal Investigator
University Hospital Tuebingen