asn.au Competing interests: Terry Haines is the director of Hospital Falls Prevention Solutions Pty Ltd. He has authored trials included in this review but he was not involved in the evaluation of these trials for the purpose of this review. Support: Terry Haines was supported by a Career Development Fellowship from the National Health

and Medical Research Council (2010–2013). “
“Functional electrical stimulation see more (FES) cycling is commonly prescribed for people with spinal cord injury for a variety of reasons (Carlson et al 2009, Hicks et al 2011). Some of the proposed benefits of FES cycling include increased urine output, decreased lower limb swelling and decreased spasticity (Elokda et al 2000, Faghri

and Yount 2002, Krause et al 2008, Sampson et al 2000, Skold et al 2002, van der Salm et al 2006). It is important to investigate the therapeutic effects of FES cycling on these variables because: increased urine output is associated with a reduced incidence of urinary tract infection (Wilde TGF-beta activation and Carrigan 2003); decreased lower limb swelling makes it easier for people with spinal cord injury to lift their legs and reduces incidence of pressure ulcers (Consortium for Spinal Cord Medicine Clinical Practice Guidelines 2001); and decreased spasticity has various functional and health benefits (Adams and Hicks 2005). Anecdotal evidence suggests that FES cycling affects renal function causing an increase in urine output and decrease in lower these limb swelling (Man et al 2003). It is hypothesised that the cyclic muscle contractions associated with FES cycling compress the lower limb vasculature thereby improving venous return and decreasing lower limb swelling (Elokda et al 2000, Faghri and Yount 2002, Man et

al 2003, Sampson et al 2000). It is also claimed that the increased venous return associated with FES cycling stretches the myocardium of the right atrium stimulating the expression of atrial natriuretic peptide. This peptide is known to have an excitatory effect on the kidneys, which increases urine excretion (Dunn and Donnelly 2007) and What is already known on this topic: Functional electrical stimulation of paralysed legs in people with spinal cord injury increases venous return which may increase urine output and decrease lower limb swelling. Functional electrical stimulation may also have short-term effects on spasticity. What this study adds: This study provides unbiased point estimates of the effect of functional electrical stimulation on urine output, venous return and spasticity. These estimates indicate that our current confidence in the effectiveness of functional electrical stimulation on these outcomes is not yet justified. FES cycling is also advocated as a way to reduce spasticity (Elbasiouny et al 2010, Krause et al 2008, Skold et al 2002, van der Salm et al 2006). Various theories exist on how this may occur.