First Advisor

Abbie Ferris

First Committee Member

Gary Heise

Degree Name

Master of Science

Document Type

Thesis

Date Created

8-2025

Department

College of Natural and Health Sciences, Kinesiology Nutrition and Dietetics, KiND Student Work

Abstract

Marijuana, Cannabis Sativa, is the most commonly used recreational drug in the United States, with more than 60 million people reporting use in 2022 (Substance Abuse and Mental Health Services Administration, 2023). As marijuana consumption has increased, so have questions surrounding its acute and long-term effects. Its acute effects are well documented; however, the long-term effects are not as well understood. It is hypothesized that chronic marijuana users will exhibit a decrease in postural stability during quiet standing when compared to non-users, so the purpose of this study was to compare postural control of chronic marijuana users and non-users in a healthy adult population. All participants in the study were healthy adults between the ages of 18-35 with no current, or history of, lower extremity injury. Each participant was categorized into one of two groups: chronic cannabis user (CAN; n = 6) or non-user (NON; n = 7). Participants in the CAN group self-reported use of cannabis at least 2x/week for a period of at least one year prior to participation while participants in the NON group self-reported no cannabis consumption for at least the period of one year prior to participation. All participants consented to a drug screen prior to participation in the study. Each participant took part in four quiet standing trials in four different conditions: rigid surface eyes closed (RSEC), rigid surface eyes open (RSEO), compliant surface eyes closed (CSEC), and compliant surface eyes open (CSEO). Center of pressure (COP) was calculated for each trial and was subsequently used to quantify postural control using the COP-based stability measures popularized by Prieto et al. (1996). These stability measures showed a significant difference between CAN and NON-groups. Significant differences in dependent variables were seen in the mean center of pressure distance traveled in the anteroposterior direction (MDIST-AP), root mean square COP distance traveled in the anteroposterior direction (RDIST-AP), and total excursion of the COP in the mediolateral direction (TOTEX-ML). Significant differences were seen between conditions for most of the calculated stability measures, but these differences were expected as surface and vision conditions were manipulated to increase task difficulty. These results suggest possible psychomotor or neuroanatomical changes may occur following long-term consumption of marijuana, and further research should be conducted to identify the underlying mechanism of these deficits in postural control. This study was conducted using a healthy adult population, but the results could have implications for other populations, especially elderly patient populations, who already exhibit a decreased ability to maintain postural control and may be exposed to negative movement-related effects of long-term prescribed consumption of marijuana.

Abstract Format

html

Disciplines

Biomechanics | Motor Control

Keywords

Marijuana; Cannabis; Postural control

Language

English

Extent

67 pages

Rights Statement

Copyright is held by the author.

Digital Origin

Born digital

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