History of cannabis use is associated with altered gait

Background: Despite evidence that cannabinoid receptors are located in movement-related brain regions (e.g., basal ganglia, cerebral cortex, and cerebellum), and that chronic cannabis use is associated with structural and functional brain changes, little is known about the long-term effect of cannabis use on human movement. The aim of the current study was to investigate balance and walking gait in adults with a history of cannabis use. We hypothesised that cannabis use is associated with subtle changes in gait and balance that are insufficient in magnitude for detection in a clinical setting. 

Methods: Cannabis users (n = 22, 24 ± 6 years) and non-drug using controls (n = 22, 25 ± 8 years) completed screening tests, a gait and balance test (with a motion capture system and in-built force platforms), and a clinical neurological examination of movement. 

Results: Compared to controls, cannabis users exhibited significantly greater peak angular velocity of the knee (396 ± 30 versus 426 ± 50°/second, P = 0.039), greater peak elbow flexion (53 ± 12 versus 57 ± 7°, P = 0.038) and elbow range of motion (33 ± 13 versus 36 ± 10°, P = 0.044), and reduced shoulder flexion (41 ± 19 versus 26 ± 16°, P = 0.007) during walking gait. However, balance and neurological parameters did not significantly differ between the groups. 

Conclusions: The results suggest that history of cannabis use is associated with long-lasting changes in open-chain elements of walking gait, but the magnitude of change is not clinically detectable. Further research is required to investigate if the subtle gait changes observed in this population become more apparent with aging and increased cannabis use.