Research participant's arm in a machine designed for motor impairment study

Motor Impairment


Program focus

The NHMRC-funded Motor Impairment Program will answer key questions about the neurophysiology, neuropathophysiology and clinical management of motor impairment.

Our research has three main themes, corresponding to three types of motor impairment that are important causes of physical disability [1,2] and commonly occur together:

1. Weakness and fatigue
2. Impaired sensation and balance
3. Contracture

For each theme (see Figure) we have identified (a) critical gaps in current understanding; (b) key questions which can be answered by emerging research techniques; and (c) promising new directions for therapeutic intervention.

Our vision is to advance the transfer of new understanding of physiology and pathophysiology in motor impairment toward the clinical outcome of improved motor function.

Our research approaches
We will conduct our studies on human volunteers and patients using a range of overlapping research approaches, from pure basic (physiological) research to applied (clinical) research. This combination of approaches will ensure that our clinical research is informed by contemporary understanding of the mechanisms of motor impairment. We will nest laboratory studies within larger clinical studies to explore the mechanisms underlying effects observed in clinical trials.

Within this spectrum of research approaches, our studies will focus on:

  • understanding normal function;
  • understanding mechanisms of motor impairment by testing people with impairment;
  • understanding mechanisms of interventions, either in healthy or impaired populations; and
  • testing clinical effects of interventions.

Many of the planned studies will examine neurophysiology and pathoneurophysiology of the motor system, namely the structures and processes which produce and control body movement.

This will involve studying the command to muscles provided by the brain, as well as the muscles that effect those commands. We will also investigate the processing of sensory information used to plan and provide ongoing control of movement.

Here are some examples of work that will take place in each of the themes:

Theme 1: Weakness and fatigue
Through randomised controlled trials, we will investigate which interventions are effective in improving movement function in multiple sclerosis, and the mechanisms underlying the changes (for example, in the ‘iFIMS Trial: Preventing Falls in People With Multiple Sclerosis’).

We will conduct laboratory studies to address the following:

  • how can we use different forms of neural stimulation to overcome weakness;
  • what does the spinal cord play in neuroplasticity;
  • what are some of the real-world effects of muscle fatigue on balance in the elderly; and
  • what are the mechanisms that contribute to ‘central’ fatigue.

Theme 2: Impaired sensation and balance
Through randomised controlled trials, we will investigate which multifactorial interventions are most effective in preventing falls in older people and the mechanisms underlying their effectiveness (for example, in the ‘iMAP Trial: Preventing Falls in Older People’).

We will conduct laboratory studies to assess the following:

the neural mechanisms underlying proprioception and the sensation of body ownership;
sensory mechanisms in stepping responses; and
the role of joint pain in sensorimotor disturbances in arthritis.
Theme 3: Contracture
We will trial novel approaches to the measurement and potentially the treatment of muscle contracture. Our laboratory studies will include studies of the ‘passive’ 3D recruitment of muscle fascicles and the properties of tendons in vivo. This work will lead to studies in clinical populations in whom contracture is common, such as people with stroke, spinal cord injury and multiple sclerosis. Our studies will also focus on understanding hand function and the changes in muscle and tendon behaviour following stroke.

1: Ada L and Canning C. Key Issues in Neurological Physiotherapy Oxford: Butterworth Heinemann, 1990, p. xv, 295 p.

2: McConnell J and Crosbie J. Key Issues in Musculoskeletal Physiotherapy. Oxford; Boston: Butterworth Heinemann, 1993, p. xv, 204 p.

See what’s going on at NeuRA


Abdominal muscle stimulation to improve bowel function in spinal cord injury

Bowel complications, resulting from impaired bowel function, are common for people living with a spinal cord injury (SCI). As a result, people with a SCI have high rates of bowel related illness, even compared with those with other neurological disorders. This includes high rates of abdominal pain, constipation, faecal incontinence and bloating. These problems lower the quality of life of people with a SCI and place a financial burden on the health system. A treatment that improves bowel function for people with a SCI should reduce illness, improve quality of life and lead to a large cost saving for health care providers. Bowel problems have traditionally been managed with manual and pharmacological interventions, such as digital rectal stimulation, enemas, and suppositories. These solutions are usually only partially effective, highlighting the need for improved interventions. The abdominal muscles are one of the major muscle groups used during defecation. Training the abdominal muscles should improve bowel function by increasing abdominal pressure. During our previous Abdominal FES research with people with a SCI, we observed that Abdominal FES appeared to lead to more consistent and effective bowel motion. However, this evidence remains anecdotal. As such, we are going to undertake a large randomised controlled trial to investigate the effectiveness of Abdominal FES to improve the bowel function of people with a SCI. This study will make use of a novel measurement system (SmartPill, Medtronic) that can be swallowed to measure whole gut and colonic transit time. We will also assess whether Abdominal FES can change constipation-related quality of life and the use of laxatives and manual procedures, as well as the frequency of defecation and the time taken. A positive outcome from this study is likely to lead to the rapid clinical translation of this technology for people living with a SCI.