World-reknown researcher, Heidi Haavik recently wrote to my association, the United Chiropractic Association, thanking them for their contribution to a ground-breaking stroke research programme that we have collectively supported. Stroke is a major global health burden and is one of the leading causes of death and disability worldwide. Thanks in a large part to the funding support, the team at the Centre for Chiropractic Research (CCR) at the New Zealand College of Chiropractic has been able to join up with researchers from Aalborg University in Denmark, and Riphah University in Pakistan, and investigate whether chiropractic care may enhance brain function in people who have suffered from a stroke.
Preliminary analysis of the data from this study was presented at World Federation of Chiropractic (WFC) 2017 in Washington, USA1 and has now been submitted for publication in a leading scientific journal. The study is still going through the peer review process, but they found some really good improvements in leg muscle weakness following a single session of chiropractic care in the stroke patients tested in ther study.
The results actually blew everyone away because the increase in strength they found was far greater than anything anyone expected to see. According to the abstract presented at the WFC, the strength increases in the affected lower limb following the single session of chiropractic care were on average 64%!! Interestingly also suggest these changes in strength come from the way the brain is driving their leg muscles, so it’s not just a local effect in the spine that we see after chiropractic care – it looks like a brain effect. This of course backs up so many other studies the New Zealand group and others around the world have done that show that chiropractic care really does change the way the brain functions.2
This line of research is very exciting for the profession. The New Zealand based group is now looking at continuing this line of research by looking at what mechanisms may underlie these changes and investigating the longer term and potential functional effects of chiropractic care in stroke recovery.
The urgent next step in this line or research is to investigate the mechanisms for this incredible finding. They will be investigating the mechanisms underlying force changes after chiropractic care in healthy participants and in chronic stroke victims. They have access to a ground-breaking new approaches to analysis that involves high density surface EMG (they have an ongoing collaboration with the pioneers in this method). The initial analysis of this collaborative study with these pioneers in this method in healthy people has shown that chiropractic care appears to be changing the conduction velocity in the muscle or the ability of the central nervous system to recruit the muscle fibres when we adjust our patients. This in a really interesting initial finding that they want to now investigate further in a larger population as well as in a chronic stroke population. So, they are now raising funds to hire a PhD student who can systematically look at this for us.
In this next planned project they will be collecting high density surface EMG from lower limb muscles pre-and post chiropractic care in both healthy populations and stroke patients. From this they will be able to tell whether chiropractic adjustments alter the recruitment pattern of motor neurons. They are also planning to record near-infrared spectrometry from the muscles they test which will be able to tell us whether there is an increased use of oxygen in these muscles post chiropractic care. This PhD project will be able to take our previous findings in strength increases a big step further.
It is very exciting for the profession about where this line of research is going, and we are proud to have contributed to the first ever research project in stroke victims looking at the effects of chiropractic care in functional recovery.
[Reproduced in abridged form from an email sent to members of the UCA from Heidi Haavik]
1. Holt K, Niazi IK, Nederggard RW, et al. The effects of a single session of spinal manipulation on strength and cortical drive in stroke patients. ACC-RAC Platform and poster presentation abstracts. . J Chiropr Educ 2017;31(1):29-83.
2. Haavik H, Murphy B. The role of spinal manipulation in addressing disordered sensorimotor integration and altered motor control. J Electromyogr Kinesiol 2012;22(5):768-76.