This biomechanical study measured the physical stretch, or strain, placed on the vertebral artery in the neck during chiropractic neck manipulation, comparing it directly with the strain caused by ordinary everyday neck movements such as turning the head or looking up.
What was studied?
Researchers measured strain at different points along the vertebral artery during manipulation performed by trained clinicians, and compared it against strain produced by ordinary head movements such as full rotation and looking upward.
What did they find?
Manipulation produced strains of roughly 1 to 6%, while everyday neck movements produced strains of roughly 3 to 12%, meaning ordinary head movements placed more strain on the artery than manipulation. Both were well below the roughly 58% strain level at which the artery is known to fail.
Why it matters
This directly addresses a common worry about neck treatment: could manipulation physically damage this blood vessel? The evidence shows manipulation strain is actually lower than from movements people already make many times a day.
Why we included it
This adds a concrete, mechanical layer of reassurance alongside large-scale patient outcome data, showing that direct physical measurement and real-world results can point to the same conclusion about a treatment's safety.
Help us improve your experience (and hopefully your back).
We use cookies to improve the website and show relevant content to people interested in our services.
We use cookies to help you navigate efficiently and perform certain functions. You can choose which categories to allow below. Cookies categorised as Necessary are always active.
We also use third-party cookies for analytics and advertising. These are only stored with your consent. You can update or withdraw consent at any time via the cookie icon at the bottom-left. This site operates under UK GDPR, the Data Protection Act 2018, and the Privacy and Electronic Communications Regulations (PECR). Cookie Policy • Privacy Policy
Always Active
Necessary cookies are required for core site features including security, network management, and consent storage.
Cookie
Duration
Description
hmdg_cookie_consent
180 days
Stores your cookie consent preferences.
PHPSESSID
Session
WordPress session identifier.
wordpress_logged_in_*
Session
WordPress login authentication.
Functional cookies enable enhanced features such as live chat and remembering preferences.
Cookie
Duration
Description
wp-settings-*
1 year
Stores user interface preferences.
Analytics cookies help us understand visitor behaviour. Controls analytics_storage for Google Analytics 4.
Cookie
Duration
Description
_ga
2 years
Google Analytics — distinguishes users.
_ga_*
2 years
Google Analytics 4 — session persistence.
_gid
24 hours
Google Analytics — distinguishes users.
_gat
1 minute
Google Analytics — throttles request rate.
Performance cookies collect aggregate, anonymous data about site performance.
Cookie
Duration
Description
_gat_gtag_*
1 minute
Google Tag Manager — rate throttle.
Marketing cookies track visits to deliver relevant ads. Controls ad_storage, ad_user_data, and ad_personalization.
What was studied?
Researchers measured strain at different points along the vertebral artery during manipulation performed by trained clinicians, and compared it against strain produced by ordinary head movements such as full rotation and looking upward.
What did they find?
Manipulation produced strains of roughly 1 to 6%, while everyday neck movements produced strains of roughly 3 to 12%, meaning ordinary head movements placed more strain on the artery than manipulation. Both were well below the roughly 58% strain level at which the artery is known to fail.
Why it matters
This directly addresses a common worry about neck treatment: could manipulation physically damage this blood vessel? The evidence shows manipulation strain is actually lower than from movements people already make many times a day.
Why we included it
This adds a concrete, mechanical layer of reassurance alongside large-scale patient outcome data, showing that direct physical measurement and real-world results can point to the same conclusion about a treatment's safety.