Almeida 2012.

Methods	Parallel group design. Randomised by pulling allocation out of a hat. Analysed on a per protocol basis. Treated as outpatients for 9 hours over 6 weeks. Assessed at baseline, 6 weeks, and 12 weeks. Assessors were blinded for UPDRS III evaluation.
Participants	14 participants in the Overground walking group (OG), 14 in the Treadmill walking group (TM), and 14 in the control group (CL). 2 dropouts in TM group, 1 dropout in CL group. Participants' mean age 73.9 years (OG), 63.9 years (TM), and 67.4 years (CL); male/female 12/2 (OG), 8/6 (TM), and 11/3 (CL); Hoehn and Yahr stage not stated; duration of PD not stated. Inclusion criteria: confirmed as having clinically typical Parkinson's disease by at least one movement disorders neurologist. Exclusion criteria: past history of neurological conditions other than Parkinson's disease, orthopaedic or visual disturbances that severely impaired walking ability, unable to independently walk down an 8‐meter GAITRite carpet for a total of 10 trials.
Interventions	OG: walk down equally spaced transverse lines presented on a 16‐m carpet. The cues were white lines of tape. Participants asked to walk across the lines, turn, and continue back. Spacings were set at 8% greater than the initial step length of any of the groups (70 cm). 30‐Minute session with mandatory 2‐minute break every 8 minutes, additional rest allowed if necessary, but a total of 24 minutes of walking was required for a gait session to be considered complete. TM: Walk on a treadmill presented with equally distributed standardised transverse white lines. Spacings were set at 8% greater than the initial step length of any of the groups (70 cm). 30‐minute session with mandatory 2‐minute break every 8 minutes, additional rest allowed if necessary, but a total of 24 minutes of walking was required for this gait session to be considered complete. CL: instructed to continue their usual activities. Participants were optimally medicated at time of all training and testing sessions and remained on stable regimen throughout trial period.
Outcomes	Step length. UPDRS III. Timed up and go. Gait speed. Cadence. Double support time. Step time. Step‐to‐step variability, Step time variability. 30‐Ssecond chair stand.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Eligibility Criteria	Low risk	Eligibility criteria stated.
Randomisation Method	High risk	Allocation pulled out of hat.
Concealment of Allocation	High risk	Allocation pulled out of hat.
Similarity at Baseline	Low risk
Withdrawals Described	Low risk	Withdrawals at less than 10%.
Intention To Treat Analysis	High risk	Analysed on a per protocol basis.
Cointerventions Constant	Low risk	Participants maintained stable drug regiment throughout trial period.
Blinded Assessors	Low risk	Assessors blind for UPDRS III evaluation only. (This is the only subjective outcome.)