FIT Exercise for Muscle Weakness Study
This study is looking at how a special type of exercise called velocity-based FIT (VBFIT) affects muscle weakness and atrophy (muscle wasting) that can happen when you don't use a limb much. You would be asked to walk with a modified shoe and crutches for 30 days, and some participants will also do VBFIT exercises. Researchers want to see if VBFIT can help maintain muscle strength, aerobic fitness, and balance. To join, you need to be between 35 and 45 years old, regularly exercise, and have a bachelor's degree or higher. The study is currently recruiting 16 participants.
- Study design
- This interventional study plans to enroll 16 participants who will be randomly assigned to either an exercise group (VBFIT) or a no-exercise group.
- What's involved
- You would participate in five testing sessions over 30 days, and if in the exercise group, perform VBFIT leg press three times per week.
- Compensation
- Not stated in the trial record.
- Follow-up
- Your muscle strength and other measures will be tracked at baseline, day 13, and day 30.
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FIT Exercise in 30d of ULLS-induced Muscle Disuse
At a glance
Conditions
Where it's being run
1 sites across 1 statesStudy leadership
- Lance Bollinger, PhD · PRINCIPAL_INVESTIGATOR · University of Kentucky
Who to contact
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Inclusion
Exclusion
What this trial measures
- Voluntary activationBaseline, day 13, and day 30
Voluntary activation of the quadriceps will be assessed with electrical stimulation of the femoral nerve before, during, and after a maximal voluntary isometric contraction (MVIC) using the interpolated twitch technique.
- Twitch Properties-Electromechanical DelayBaseline, day 13, and day 30
Electromechanical delay will be calculated as the time difference between the onset of electrical impulse and onset of torque development during femoral nerve stimulation. This will be measured before and after a maximal voluntary isometric contraction.
- Twitch Properties-Rate of Torque DevelopmentBaseline, day 13, and day 30
Rate of Torque Development will be calculated as the change in torque divided by the change in time in the linear phase between 20 and 80% of peak twitch torque during femoral nerve stimulation. This will be measured before and after a maximal voluntary isometric contraction.
- Twitch Properties-Time to peak TensionBaseline, day 13, and day 30
Time to peak tension will be calculated as the time difference between the onset of electrical impulse and peak twitch torque during femoral nerve stimulation. This will be measured before and after a maximal voluntary isometric contraction.
- Twitch Properties-Peak Twitch TorqueBaseline, day 13, and day 30
Peak twitch torque during femoral nerve stimulation will be calculated as the highest torque output immediately (approximately 200ms) following femoral nerve stimulation. This will be measured before and after a maximal voluntary isometric contraction.
- Twitch Properties-Relaxation RateBaseline, day 13, and day 30
Relaxation rate will be calculated as the change in torque divided by the change in time during the relaxation phase of twitch following femoral nerve stimulation. This will be measured before and after a maximal voluntary isometric contraction.
- Post activation PotentiationBaseline, day 13, and day 30
Post-activation will be calculated as the percentage difference in peak twitch torque in femoral nerve stimulation before and after a maximal voluntary isometric contraction.
- Motor unit action potential train (MUAPT) firing rateBaseline, day 13, and day 30
Firing rate of individual motor units of the vastus lateralis (VL) will be assessed with high density surface electromyography (EMG) using four-pin high density surface electromyography electrodes. Firing rate at 30, 60, and 90% MVIC will be reported. Motor unit firing rate will also be reported during static stance. Participants will use a screen displaying real-time torque output. Participants will voluntarily increase torque (5 seconds), hold at a pre-determined torque level (10 seconds), and gradually reduce force back to resting (5 seconds) with the knee held in a fixed position. This test will be completed with a 10s isometric hold at 30, 60, and 90% of maximal voluntary isometric force.
- Motor unit action potential train (MUAPT) recruitment threshold.Baseline, day 13, and day 30
Recruitment threshold of individual motor units of the VL will be assessed with high density surface electromyography using four-pin high density surface electromyography electrodes. Recruitment threshold will be measured during isometric ramp contractions of the quadriceps Participants will use a screen displaying real-time torque output. Participants will voluntarily increase torque (5 seconds), hold at a pre-determined torque level (10 seconds), and gradually reduce force back to resting (5 seconds) with the knee held in a fixed position. This test will be completed with a 10s isometric hold at 30, 60, and 90% of maximal voluntary isometric force.
- Motor unit action potential train (MUAPT) de-recruitment threshold.Baseline, day 13, and day 30
De-recruitment threshold of individual motor units f the VL will be assessed with high density surface electromyography using four-pin high density surface electromyography electrodes. Recruitment threshold will be measured during isometric ramp contractions of the quadriceps Participants will use a screen displaying real-time torque output. Participants will voluntarily increase torque (5 seconds), hold at a pre-determined torque level (10 seconds), and gradually reduce force back to resting (5 seconds) with the knee held in a fixed position. This test will be completed with a 10s isometric hold at 30, 60, and 90% of maximal voluntary isometric force.
- Muscle sizeBaseline and day 30
Muscle size will be measured by MRI. Anatomical MRI scans will allow for assessment of anatomical cross sectional area.
- Muscle Physiological cross-sectional areaBaseline and day 30
Diffusion tensor imaging (DTI) will be used to assess muscle volume and fascicle length. Physiological cross-sectional area will be calculated as Muscle volume divided by fascicle length.
- Muscle Fractional AnisotropyBaseline and day 30
Diffusion tensor imaging (DTI) will be used to assess anisotropic measures. A ratio of the diffusivity in the principal planes will be used to calculate fractional anisotropy.
- Muscle Diffusion propertiesBaseline and day 30
Diffusion tensor imaging (DTI) will be used to assess rate of water diffusion in three principal planes. We will report rates of water diffusion in three ways: 1) mean diffusivity (average rate in all three plane), 2) axial diffusivity (rate of diffusion along primary axis), and 3) radial diffusivity (rate of diffusion perpendicular to the primary axis).
- Muscle cross-sectional area (Ultrasound)Baseline, day 13, and day 30
cross-sectional area of the vastus lateralis and rectus femoris will be measured by ultrasonography
- Fascicle lengthBaseline, day 13, and day 30
Panoramic views of the mid-portion of the VL will be measured by ultrasonography
- Pennation angleBaseline, day 13, and day 30
Pennation angle of the mid-portion of the vastus lateralis will be assessed by ultrasonography
- Voluntary Isokinetic Muscle StrengthBaseline, day 13, and day 30
Maximal voluntary isokinetic concentric strength of the knee extensors/flexors and ankle dorsi-/plantar-flexors will be assessed at 60 deg/s
- Voluntary Isometric Muscle StrengthBaseline, day 13, and day 30
Maximal voluntary isometric strength of the knee extensors/flexors and ankle dorsi-/plantar-flexors will be assessed during a (10 seconds) maximal effort contraction.