CYBERSPACE—According to media reports, researchers at the University of Southern Australia recently published a study that found marijuana users’ gait differs slightly from the way non-marijuana users walk. Citing increasing cannabis legalization in the United States, media outlets like MSN.com highlighted the importance of more substantial studies on the effects of cannabis.
Media outlets, however, did not highlight current federal policies that cripple efforts to conduct academic cannabis research in the United States, and the stigma attached to cannabis by its designation as a Schedule 1 narcotic.
The study, titled “History of cannabis use is associated with altered gait,” which was published in medical journal Drug and Alcohol Dependence, followed two groups of subjects, each comprised of twenty-two participants. One group did not use cannabis, and the other group had a history of cannabis use (at least five incidents of use), but without history of using other drugs like opiates or amphetamines.
By measuring knee movement in subjects, the researchers found that:
- Cannabis users exhibit increased angular velocity of the knee during walking gait.
- Cannabis users exhibit reduced shoulder flexion during walking gait.
- Gait changes in cannabis users are not of a magnitude that is clinically detectable.
There was no measurable difference in balance. However, a 2008 study found that marijuana use did have an affect on users’ ability to balance, when measured by “body sway.”
Study co-author Verity Pearson-Dennett admitted to PsyPost.org the study was limited by a number of conditions, and said, “This was a small pilot study, therefore a number of questions need to be addressed. For example, does a greater amount of cannabis use mean a greater level of impairment? Does the strain or THC/CBD content of the cannabis used change the level of impairment observed?”
On PsyPost.org, Pearson-Dennett also said, “The changes in walking were small enough that a neurologist specializing in movement disorders was not able to detect changes in all of the cannabis users. However, many of the participants in the cannabis group were moderate-to-light cannabis users, therefore heavier cannabis users may have greater impairments.”
MedicalDaily.com also quoted Pearson-Dennett, who added that, “the physiological mechanisms that underpin changes in movement are not well understood.”
The MSN.com post (and others) also cautioned readers that several other physical and neurological can be linked to cannabis, and said, “It’s known marijuana can significantly impair judgement (sic), motor coordination, and reaction time. Specifically, when it comes to driving, studies have found there’s a direct relationship between blood THC concentration and an impaired ability to drive. Moreover, marijuana may cause orthostatic hypotension (head rush or dizziness on standing up), possibly raising danger from fainting and falls, according to the National Institute on Drug Abuse.”