“…Individuals who abuse elicit substances have an increase risk of negative consequences such as suicide, arrest/incarceration, homelessness, family conflicts, violence and destructive behaviours, victimization, physical health problems and Gbiri et al 93 quality of life (Foster et al, 1999;Lorenz et al, 2001;Rudolf and Watts, 2002;Morgan et al, 2003;Fassino et al, 2004;Okoro et al, 2004;Vorma et al, 2004;Dalgard et al, 2004;Chen et al, 2006;Costenbader et al, 2007;Urbanoski et al, 2007;Korthuis et al, 2008;Lahmek et al, 2009). Some of the most observed physical problems in individuals who abuse illicit substances are balance and gait instability as well as postural disorientation (Torvik and Torp, 1986;Victor et al, 1989;Sullivan et al, 2000a, b;Sullivan et al, 2004;Deshmukh et al, 2002).…”