None listed
Conditions
Brief summary
This experiment is designed to assess cortical and neuromuscular mechanisms involved in control of leg muscles and how these are modulated by standing on a vibration platform. The study will help us to understand the effect of whole body vibration on the contribution of cortical function and reflex pathways to maintaining balance during quiet standing. This may have implications with regard to prescription of whole body vibration for enhancing exercise prescription that leads to improved function of lower leg muscles for young and older individuals. This may have important implications for optimisation of exercise for strength, endurance and balance. Volunteers will attend the lab on two occasions. During one visit they will undergo transcranial magnetic stimulation in a standing position with feedback about their muscle activation level, and without the feedback. They will then stand on the vibration platform for 5 minutes with breaks after each minute and repeat the brain stimulation tests. On the second occasion they will lay on a massage table while the tibial nerve is stimulated with an electrical pulse to measure H reflex. They will again stand on the vibration platform for 5 minutes with breaks after each minute and repeat the H reflex test.
Interventions
Volunteers will stand on a vibration platform for 5 minutes in 1 minute blocks with 30 seconds breaks between. Frequency will be 25-55 Hz at an amplitude of 4mm. EMG will be used to measure H reflex and M wave before and after the WBV by electrically stimulating the tibial nerve in blocks of 5 stmuli at least 10 seconds apart starting at 2mV intensity and gradually increasing the stimulus until the h reflex is elicited. The interval between blocks will be at least 15 seconds. Stimulation increas
Volunteers will stand on a vibration platform for 5 minutes in 1 minute blocks with 30 seconds breaks between. Frequency will be 25-55 Hz at an amplitude of 4mm. EMG will be used to measure H reflex and M wave before and after the WBV by electrically stimulating the tibial nerve in blocks of 5 stmuli at least 10 seconds apart starting at 2mV intensity and gradually increasing the stimulus until the h reflex is elicited. The interval between blocks will be at least 15 seconds. Stimulation increase is continued and eventually the h reflex is no longer seen as the m wave continues to increase. Stimulation is stopped when the m wave reaches plateau, usually around 50 mA and up to 100 stimuli will be delivered before and another 100 after WBV. The threshold and intensity of the stimulus varies greatly between subjects. Cortical function will be measured by stimulating the motor cortex with transcranial magnetic brain stimulation. A PhD qualified Neuromuscular physiologist with more than 12 years experience will carry out all procedures.
Sponsors
Curtin University
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
Volunteers will be aged between 18 and 80 years and have no contraindications to electrical or magnetic stimulation or use of a whole body vibration platform.
Exclusion criteria
Use of a pacemaker, any neurological disorder including migraine and severe arthritis or other joint pain that may be exacerbated by whole body vibration.
Outcome results
None listed