Study	Reason for exclusion
Avramidis 2003	No strength measurement recorded pre or post neuromuscular stimulation
Gibson 1989	No strength outcomes recorded for the control group. No comparison possible with regard to strength
Goitlin 1994	No measurement of quadriceps strength recorded pre or post neuromuscular electrical stimulation.
Haug 1988	Group contained two people with rheumatoid arthritis but which group they were assigned to was unclear.It was not possible to differentiate the study findings for the non rheumatoid group alone.
Lewek 2001	Single case study.
Martin 1991	No strength measurement recorded pre and post neuromuscular stimulation.
Mintken 2007	Single case study.
Novak 1991	No strength measurement recorded pre and post neuromuscular stimulation.
Petterson 2006	Single case study.
Rodgers 1998	Content of Physiotherapy programme unclear from abstract. The full article showed that no neuromuscular stimulation was used in the preoperative physiotherapy programme.
Stevens 2004a	Case series
Toro 1997	No strength measurement recorded pre and post neuromuscular stimulation.
Zizic 1995	Abstract only available, Full paper sought but was found impossible to locate with the stated reference. No measurement of quadriceps strength pre or post neuromuscular stimulation is reported in the abstract.