Ambulation in simulated fractional gravity using lower body positive pressure: cardiovascular safety and gait analyses
Ambulation in simulated fractional gravity using lower body positive pressure: cardiovascular safety and gait analyses
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DOI：
10.1152/japplphysiol.00644.2005
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发表时间：
2006-09-01
影响因子：
3.3
通讯作者：
Hargens, Alan R.
中科院分区：
文献类型：
--
作者：
Cutuk, Adnan;Groppo, Eli R.;Hargens, Alan R.
本研究的目的是评估对下体正压（LBPP）的心血管反应，并检查LBPP卸载对跑步机步行期间步态力学的影响。我们假设LBPP允许身体舒适地卸载，对心血管系统和步态参数的影响最小。15名健康男性和女性受试者（22-55岁）自愿参加研究。9例在LBPP中站立和直立行走时进行了无创心血管研究，6例完成了步态分析协议。站立时，心率从环境压力下的83 +/- 3次/分显著下降到50 mmHg LBPP下的73 +/- 3次/分（P < 0.05）。在以3 mph（1.34 m/s）的LBPP进行Ambestion期间，心率从环境压力下的99 +/- 4次/min显著降低至50 mmHg LBPP下的84 +/- 2次/min（P < 0.009）。血压、脑氧合、大脑中动脉血流速度和头部皮肤微血管血流没有明显变化。在LBPP允许的范围内，以60%和20%体重行走可降低地面反作用力（P < 0.05），而膝关节和踝关节的矢状运动范围不受影响。总之，在LBPP中行走对全身和头部心血管参数没有不良影响，同时产生显著的减重和步态运动学的最小改变。因此，在LBPP内行走可能是一种新的安全的康复工具，可减少患者下半身肌肉骨骼结构的负荷，同时保留步态力学。
The purpose of this study is to assess cardiovascular responses to lower body positive pressure ( LBPP) and to examine the effects of LBPP unloading on gait mechanics during treadmill ambulation. We hypothesized that LBPP allows comfortable unloading of the body with minimal impact on the cardiovascular system and gait parameters. Fifteen healthy male and female subjects (22-55 yr) volunteered for the study. Nine underwent noninvasive cardiovascular studies while standing and ambulating upright in LBPP, and six completed a gait analysis protocol. During stance, heart rate decreased significantly from 83 +/- 3 beats/min in ambient pressure to 73 +/- 3 beats/min at 50 mmHg LBPP ( P < 0.05). During ambulation in LBPP at 3 mph (1.34 m/s), heart rate decreased significantly from 99 +/- 4 beats/min in ambient pressure to 84 +/- 2 beats/min at 50 mmHg LBPP ( P < 0.009). Blood pressure, brain oxygenation, blood flow velocity through the middle cerebral artery, and head skin microvascular blood flow did not change significantly with LBPP. As allowed by LBPP, ambulating at 60 and 20% body weight decreased ground reaction force ( P < 0.05), whereas knee and ankle sagittal ranges of motion remained unaffected. In conclusion, ambulating in LBPP has no adverse impact on the systemic and head cardiovascular parameters while producing significant unweighting and minimal alterations in gait kinematics. Therefore, ambulating within LBPP is potentially a new and safe rehabilitation tool for patients to reduce loads on lower body musculoskeletal structures while preserving gait mechanics.