Effect of Neuromuscular Electrical Stimulation Combined With Varying Degrees of Blood Flow Restriction on Muscular and Cardiovascular Function
试验速览
- 阶段
- 不适用
- 入组人数
- 50
- 主要终点
- Knee extension isometric, eccentric, concentric and endurance strength (Cybex)
研究概览
简要总结
Neuromuscular electrical stimulation (NMES) has recently been combined with blood flow restriction (BFR) in controlled trials and has shown increased muscular strength and size compared with NMES and BFR on their own. However, none have used BFR pressures previously recommended. The first study of my Ph.D. found 40% and 80% BFR pressures to induce acute fatigue and muscle swelling. However, 80% caused higher ratings of pain and perceived exertion. The present study will determine whether NMES combined with either 40% or 80% BFR causes greater structural muscular adaptations and is perceptually easier after 6 weeks of training.
详细描述
Laboratory testing will take place on 28 separate occasions, 2 familiarisation, 8 testing and 18 intervention sessions. The first session (FAM 1) will serve as a familiarisation trial to the NMES protocol, BFR stimulus and strength testing. It will be conducted 10-14 days prior to the intervention period. The second session (FAM 2) will serve as a second familiarisation trial to the NMES protocol, BFR stimulus and strength testing. This session will take place 7 days prior to the beginning of the intervention period and will serve as a standardised control period prior to the main testing. The third session (PRE) will take place 1 day prior the start of the intervention period and all future sessions will consist of strength, muscle and cardiovascular function outcome measures. The fourth session (MID) will take place the morning following 3 weeks of training. The fifth session (POST1) will take place 48 hours following 6 weeks of training. There will also be post testing sessions after three days (POST2), one week (POST3) and two weeks post intervention (POST4) to assess detraining. Participants will be provided with protein supplementation after every training session. All strength, muscle and hemodynamic measurements will be conducted at St Marys University by Paul Head. Supplements should be avoided for 72 hours prior to experimental measures and throughout the intervention period. All repeated measures will be performed at a similar time of day (± 1 h).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy adults aged between 18 and 45 years old
排除标准
- •History of lower extremity surgery, traumatic injuries to the ankle, knee, hip, pelvis and lower back
- •Current musculoskeletal condition
- •High blood pressure
- •Cardiovascular pathology
研究组 & 干预措施
NMES and BFR (80%)
Group 1, participants will undergo NMES and BFR (80% pressure) applied to the quadriceps for 25 min.
干预措施: Neuromuscular electrical stimulation (Device)
NMES and BFR (40%)
Group 2, participants will undergo NMES and BFR (40% pressure) applied to the quadriceps for 25 min.
干预措施: Neuromuscular electrical stimulation (Device)
NMES alone
Group 3, participants will undergo NMES applied to the quadriceps for 25 min.
干预措施: Neuromuscular electrical stimulation (Device)
结局指标
主要结局
Knee extension isometric, eccentric, concentric and endurance strength (Cybex)
时间窗: 8 weeks
Maximal isometric, eccentric and concentric strength of the quadricep muscles will be measured using the same isokinetic dynamometer to assess peak force measurements (Cybex). This digital strain gauge dynamometer displays the force measurement to the nearest 0.1 N. Prior to each measurement, the instrument will be calibrated per the manufacturer's instructions and specifications. The individuals will be seated in a comfortable position with the backrest angled at 100˚ to the seat without shoes or orthotic device on. Maximal voluntary isometric contraction (MVIC) for the quadriceps will tested at 60 degrees from full extension using a goniometer (19-21), and the shin pad positioned 2 cm above the lateral malleolus of the fibula attached to a load cell (22).
Quadriceps volume and muscle architecture (3D Ultrasound)
时间窗: 8 weeks
Muscle volume of the vastus lateralis and skeletal muscle architecture will be assessed by ultrasound technique (Telemed LogicScan 128 EXT-1Z). Measurement of fascicle length and pennation angle will be acquired at mid-belly, in the mid-sagittal plane.
次要结局
- Voluntary activation(8 weeks)
- Near-infrared spectroscopy(8 weeks)
- Blood pressure(8 weeks)
研究者
Paul Head
PhD candidate
St. Mary's University, Twickenham