None listed
Conditions
Brief summary
Hamstring strain injuries (HSIs), occurring primarily in the biceps femoris long head, have been shown to lead to an increased likelihood of re-injury. These injuries also lead to decreased muscle activity in eccentric contractions, persistent deficits in muscle architecture (i.e., the internal structure of the muscle) and motor pattern changes. Recent evidence also demonstrates that post injury, inhibition exists at the brain (or cortical) level. This inhibition can lead to reduced strength and changes in muscle architecture that can increase injury risk. The aim of this project is to investigate the effects of a strength training program combined with active or sham tDCS on cortical inhibition, hamstring strength and biceps femoris long head architecture. Our hypothesis is that muscle fascicle length and hamstring strength will increase more in the active tDCS condition rather than the sham condition.
Interventions
Randomised control trial to determine the effect of non invasive brain stimulation (transcranial direct current stimulation) on architectural changes resulting from a six-week eccentric training intervention (intervention total: 8 weeks, including pre-, post-testing and familiarisation) on an isokinetic dynamometer. All sessions will be supervised by a researcher.
The tDCS intervention will be 20 minutes and a 2 mA intensity, the eccentric training will include 2 - 4 sets of 4 - 6 repetitions,
Randomised control trial to determine the effect of non invasive brain stimulation (transcranial direct current stimulation) on architectural changes resulting from a six-week eccentric training intervention (intervention total: 8 weeks, including pre-, post-testing and familiarisation) on an isokinetic dynamometer. All sessions will be supervised by a researcher. The tDCS intervention will be 20 minutes and a 2 mA intensity, the eccentric training will include 2 - 4 sets of 4 - 6 repetitions, depending on the week. The tDCS will be applied with the anode over the contralateral motor cortex of the leg being trained and the cathode over the forehead opposite the anode prior to training. The participant comfort to tDCS will be assessed via a 0-10 RPE scale. Eccentric training will be maximal efforts performed on an isokinetic dynomometer. Total session duration will be 2x 60mins in weeks one and two and 1x 45mins during weeks three to six. The exercise performed will be an eccentric contraction of the hamstrings. Participants will be randomised into two groups, active-tDCS and sham-tDCS. During the first two weeks of the study, participants will attend the laboratory twice, and once in the latter four weeks. Participants will also attend pre and post training sessions to obtain baseline measures and a familiarisation session, making the full duration of the intervention eight to nine weeks. Pre and post baseline measures taken will include, hamstring fascicle length taken via ultrasound, active motor threshold taken via transcranial magnetic stimulation and maximal muscle strength. Active motor threshold will also be taken in weeks 2, 4 and 6. Attendance and training session will be monitored via the universities REDCap system.
Sponsors
Australian Catholic University
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
1. Currently free of any major lower limb injury at the time of testing. 2. Are currently participating in regular recreational physical activity.
Exclusion criteria
1. Have previously suffered a seizure 2. Current or history of neurological diseases (E.g. epilepsy, Parkinson’s, Alzheimer’s, multiple sclerosis, stroke) AND have no family history of neurological disease. 3. Have embedded material in the skull such as metal fragments/plates, cochlear implants, or brain stimulation device. 4. Have sustained a concussion within the past three months. 5. Have sustained a hamstring strain injury (HSI) within the past 36 months. 6. Have never sustained an anterior cruciate ligament (ACL) injury at any point.
Outcome results
None listed