Dr Harrison Finn


Postdoctoral Fellow

+61 2 9399 1629

Harrison completed his Bachelor of Health Science (Sports and Exercise Science) with Honors and Master of Clinical Exercise Physiology before starting his PhD in 2015.

Projects Dr Harrison Finn is currently involved with


Brain and Knee Muscle Weakness Study

Why Does Quadriceps Weakness Persist after Total Knee Replacement?

An Exploration of Neurophysiological Mechanisms

Total knee replacement is a commonly performed surgery for treating end-staged knee osteoarthritis. Although most people recover well after surgery, weakness of the quadriceps muscles (the front thigh muscles) persists long after the surgery (at least for 12 months), despite intensive physiotherapy and exercise. Quadriceps muscle weakness is known to be associated with more severe pain and greatly affect daily activities.

This study aims to investigate the mechanisms underlying weakness of the quadriceps muscles in people with knee osteoarthritis and total knee replacement. We hope to better understand the relationship between the changes of the brain and a loss of quadriceps muscle strength after total knee replacement.

The study might be a good fit for you if you:

  • Scheduled to undergo a total knee replacement;
  • The surgery is scheduled within the next 4 weeks;
    • Do not have a previous knee joint replacement in the same knee;
    • Do not have high tibial osteotomy;
    • Do not have neurological disorders, epilepsy, psychiatric conditions, other chronic pain conditions;
    • Do not have metal implants in the skull;
    • Do not have a loss of sensation in the limbs.

If you decide to take part you would:

  • Be contacted by the researcher to determine your eligibility for the study
  • Be scheduled for testing if you are eligible and willing to take part in the study
  • Sign the Consent Form when you attend the first testing session
  • Attend 3 testing sessions (approximately 2 hours per session): 1) before total knee replacement, 2) 3 months and 3) 6 months after total knee replacement. The testing will include several non-invasive measures of brain representations of the quadriceps muscles, central pain mechanisms, and motor function and questionnaires.

Will I be paid to take part in the research study?

You will be reimbursed ($50.00 per session) for travel and parking expenses associated with the research study visits.

If you would like more information or are interested in being part of the study, please contact:

Name: Dr Wei-Ju Chang

Email: w.chang@neura.edu.au

Phone: 02 9399 1260

This research is being funded by the Physiotherapy Research Foundation.



Brain and Knee Muscle Weakness Study

BOOST – Repetitive transcranial magnetic simulation to bolster analgesic effects of quadriceps str

Osteoarthritis affects more than 20% of Australians aged over 60. The knee joint is commonly affected, causing persistent pain and difficulty in daily activities. Although exercise is the cornerstone of conservative treatment for knee osteoarthritis and recommended in all international guidelines, its effects are, at best, moderate.

BOOST is a ‘proof of concept’ study to explore the use of a novel intervention combining non-invasive brain stimulation and exercise therapy in people with knee osteoarthritis. This intervention applies repetitive transcranial magnetic stimulation, a safe and painless non-invasive brain stimulation, targeting specifically the brain region involved in pain processing and motor function to enhance the effects of exercise therapy.

The study might be a good fit for you if you:

  • Are aged ≥ 50 years with knee osteoarthritis.
  • Have knee pain for more than 3 months and on most days of the past month.
  • Have average pain intensity higher than 4 out 10 in the past week.
  • Do not have previous knee joint replacement or high tibial osteotomy.
  • Do not knee surgery or joint injection in past 6 months.
  • Do not have planned surgery in the next 9 months.
  • Do not use oral corticosteroids currently or in the past 4 weeks.
  • Do not have systemic arthritis, previous knee fracture or malignancy.
  • Do not have other condition affecting lower limb function.
  • Do not participate in knee strengthening exercise in past 6 months.
  • Do not have a loss of sensation of the affected leg.
  • Do not have neurological or psychiatric disorders.
  • Do not have contraindications to brain stimulation such as epilepsy, metal implant in the skull.
  • Do not use neuroactive drugs.

If you are eligible and agree to participate, you will be asked to attend 2 sessions per week for 6 weeks (each session includes 15 minutes of active or sham brain stimulation plus 30 minutes one-to-one exercise by a physiotherapist); 2 testing sessions (about 1.5 hours per session) before the start and after the completion of the intervention. All sessions will take place in a laboratory at NeuRA.

If you would like more information or are interested in being part of the study, please contact:

Name: Dr Wei-Ju Chang

Email: w.chang@neura.edu.au

Phone: 02 9399 1260

Like to see if you’re eligible? Click here

This research is being funded by the ANZMUSC Clinical Trial Network.


BOOST – Repetitive transcranial magnetic simulation to bolster analgesic effects of quadriceps strengthening exercise in knee osteoarthritis

Abdominal Functional Electrical Stimulation for Orthostatic Hypotension in Spinal Cord Injury

Spinal cord injury (SCI) results in the loss of function to not only voluntary motor control, but also to the regulatory systems that control bodily processes. Orthostatic (postural) hypotension (OH) is a common clinical feature in SCI patients, affecting up to 73% of patients with cervical spine and upper thoracic spine injuries during mobilisation and postural changes. This often results in symptoms of dizziness, light-headedness, fatigue and confusion, in turn limiting individual participation in physical rehabilitation and restricting progress towards regaining function and independence.

Therapeutic interventions are centred around ameliorating symptoms of OH; however, options for patients remain limited. Non-pharmacological treatments have had little success at treating hypotension in the long-term, while pharmacological interventions are used only when necessary as they may contribute to hypertension and even worsen episodes of autonomic dysreflexia, a life-threatening condition.

Functional Electrical Stimulation (FES) is one of the only interventions that has been shown to display some benefit in improving OH. Recently, stimulation of the lower limbs has been shown to acutely increase blood pressure in patients with SCI. Our recent projects have involved the use of FES applied over the abdominal muscles, termed abdominal FES, for SCI patients at risk of respiratory complications with promising results. As this same population is at risk of orthostatic hypotension, this study aims to determine whether abdominal stimulation can also be used to help this condition.

Based on our previous research, we believe that abdominal FES will increase blood pressure acutely during an orthostatic challenge in individuals with acute spinal cord injury, allowing for a longer time spent in a standing position. This will facilitate more effective rehabilitation, therefore improving quality of life and decreasing associated medical complications.


Abdominal Functional Electrical Stimulation for Orthostatic Hypotension in Spinal Cord Injury

Accelerating ventilator weaning in spinal cord injury with non-invasive Abdominal Stimulation: a ran

While tetraplegia is commonly associated with paralysis of all four limbs, paralysis also affects the major respiratory muscles, namely the diaphragm, abdominal and intercostal muscles. The reduction in respiratory function results in approximately 40% of tetraplegic patients requiring mechanical ventilation in the acute stage (first six weeks) of injury to support respiration. The use of mechanical ventilation increases lifelong morbidity and mortality, delays rehabilitation, results in longer hospital stays and costs the health care provider an additional $2,000 per patient per day.

Surface electrical stimulation of the abdominal muscles, termed Abdominal Functional Electrical Stimulation (FES), can contract the abdominal muscles, even when paralysed.  We have shown that surface FES of the abdominal muscles, termed Abdominal FES, improves respiratory function in tetraplegia, and respiratory function is a known predictor of mechanical ventilation time. Dr McCaughey’s pilot work also shows that eight weeks of abdominal FES is a feasible method to reduce mechanical ventilation time in acute tetraplegia.

Despite these positive results, a lack of data from randomised control trials, and lack of a standard Abdominal FES protocol, has prevented this technology from being adopted as a standard clinical treatment.

This project will provide the first information on the effectiveness and cost-effectiveness of Abdominal FES to reduce mechanical ventilation duration in tetraplegia. In addition, it will provide detailed information about respiratory function and its impact on quality of life in tetraplegia.

This is an international collaboration brings together leading research and medical teams from: Neuroscience Research Australia, the Prince of Wales Hospital, Royal North Shore Hospital, Austin Health and Fiona Stanley Hospital in Australia; The Indian Spinal Cord Injury Centre and the Christian Medical College, Vellore, in India; The Queen Elizabeth National Spinal Injuries Unit and the University of Glasgow in Scotland; Middlemore Hospital in Auckland, New Zealand, and the University of Alberta and McMaster University in Canada.


Accelerating ventilator weaning in spinal cord injury with non-invasive Abdominal Stimulation: a randomised controlled trial




The Magnitude of Peripheral Muscle Fatigue Induced by High and Low Intensity Single-Joint Exercise Does Not Lead to Central Motor Output Reductions in Resistance Trained Men.

Marshall PW, Finn HT, Siegler JC

Maximal central motor output in resistance trained men is well preserved despite varying levels of peripheral muscle fatigue. Upregulated central motor output during the 40% contraction protocol appeared to elicit greater peripheral fatigue. V-waves declines during the 80% protocol suggest intensity dependent modulation of the Ia afferent pathway.

Muscle activation does not increase after a fatigue plateau is reached during 8 sets of resistance exercise in trained individuals.

Finn HT, Brennan SL, Gonano BM, Knox MF, Ryan RC, Siegler JC, Marshall PW

The premise of eliciting the greatest acute fatigue is accepted and used for designing programs that include excessive, potentially dangerous volumes of high-intensity resistance exercise. There is no evidence examining acute fatigue and neuromuscular responses throughout multiple sets of moderate-to-high intensity resistance exercise. Fifteen resistance-trained male subjects performed a single exercise session using 8 sets of Bulgarian split squats performed at 75% maximal force output. Maximal force output (N) was measured after every set of repetitions. Electromyographic (EMG) activity of vastus lateralis was monitored during all force trials and exercise repetitions. Repetitions per set decreased from the first to the third set (p < 0.001). Maximal force output decreased from preexercise to set 4 (p < 0.001). Electromyographic amplitudes during exercise did not change. Secondary subgroup analysis was performed based on the presence, or not, of a fatigue plateau (<5% reductions in maximal force output in subsequent sets). Nine participants exhibited a fatigue plateau, and 6 did not. Participants who plateaued performed less first-set repetitions, accrued less total volume, and did not exhibit increases in EMG amplitudes during exercise. Initial strength levels and neuromuscular demand of the exercise was the same between the subgroups. These data suggest that there are individual differences in the training session responses when prescribing based off a percentage of maximal strength. When plateaus in fatigue and repetitions per set are reached, subsequent sets are not likely to induce greater fatigue and muscle activation. High-volume resistance exercise should be carefully prescribed on an individual basis, with intrasession technique and training responsiveness continually monitored.