The Effect of Gravity on the Muscular Control of Landing From a Jump
试验速览
- 阶段
- 不适用
- 入组人数
- 18
- 试验地点
- 2
- 主要终点
- Electromyography (Amplitude - mV and latency - ms)
研究概览
简要总结
In this project, investigators propose to study the jump in different reduced gravity fields obtained during parabolic flights profiles but also during increased gravity fields obtained during turns of the airplane or during the pull-up phase of the parabola. By means of a pneumatic device, an additional pull-down force will be added to the vertical force caused by the gravity field. By combining different levels of gravity to different levels of the added pull-down force it will be possible to dissociate the respective contribution of the otolithic and proprioceptive systems to the anticipatory landing response. To the investigators' knowledge, only one study has modified the gravity field during a jump. However, these authors did not add a pull-down force and only analyzed the vertical ground reaction force.
A better knowledge of the sensory-motor control of the landing phase of a jump will also increase the investigators' understanding of the physiopathology of joint instability. Indeed, similarities could be found between the evolution of the motor response due to the absence gravity during long-duration space flights and the pathological process of chronic ankle and knee instability. The knowledge generated by this study will thus provide invaluable information in the context of human performance and rehabilitation.
详细描述
Investigations description ----------------------------------
During the experiments, subjects will jump in different gravity fields while submitted to an additional pull-down force equal to 0-100% of their body weight on Earth. During the takeoff and landing phases of the jumps, the ground reaction force will be recorded by a force-platform, the movements of the limb segments will be recorded by means of a high-speed camera and the electrical activity (EMG) of the main lower limb muscles will be recorded by means of surface electrodes.
Force platform and Subject Loading System We have developed a device that combines a force platform on which the subject jumps and a Subject Loading System (SLS) that pulls the subject downwards.
The force platform is a 60 cm x 40 cm aluminum plate equipped with four force-transducers that measure the three components of the force exerted by the subject's feet on the ground.
The SLS consists in two pneumatic pistons, which are attached to a harness on one end and to the aluminum plate on the other. The SLS can be set to generate a force equal to 20-100% of the subject's body weight on Earth.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy volunteers (men or women)
- •Aged from 18 to 65
- •Affiliated to a Social Security system and, for non-French resident, holding a European Health Insurance Card (EHIC)
- •Who accepted to take part in the study
- •Who have given their written stated consent
- •Who has passed a medical examination similar to a standard aviation medical examination for private pilot aptitude. There will be no additional test performed for subject selection
排除标准
- •Person who took part in a previous biomedical research protocol, of which exclusion period is not terminated
- •Pregnant women
- •Person with medical history of musculoskeletal disorders of the lower limbs, pelvis or spine, neurological or vestibular disorders.
结局指标
主要结局
Electromyography (Amplitude - mV and latency - ms)
时间窗: baseline
EMG (electrical activity produced my muscles when they contract) will be recorded with a MyoSystem 1400L using surface electrodes at the level of the lateral gastrocnemius, medial gastrocnemius, tibialis anterior and peroneus longus, and on the thigh at the level of the vastus lateralis, vastus medialis and lateral hamstrings and medial hamstrings. EMG activation (amplitude and latency) will be measured during jumps at different level of gravity and pull-down forces.
次要结局
未报告次要终点