Frazzitta 2009.

Methods	Randomised controlled trial Method of randomisation: not described Blinding of outcome assessors: unclear Adverse events: not stated Deaths: none Drop‐outs: none ITT: yes
Participants	Country: Italy 40 patients (20 in treatment group, 20 in control group) Ambulatory at study onset: yes Mean age: 71 years (control and treatment group) Inclusion criteria: being able to walk without any physical assistance, sufficient vision and hearing, freezing of gait during peak medication (confirmed by clinical examination), Hoehn & Yahr stage 3, Mini Mental State Examination Score >26), constant medication Exclusion criteria: neurological conditions other than idiopathic Parkinson’s disease, postural hypotension, cardiovascular, musculoskeletal, or vestibular disorders limiting locomotion or balance
Interventions	2 arms: (1) control group used traditional rehabilitation with visual and auditory cues, 7 times a week for 4 weeks (140 min a week) (2) experimental group received treadmill training with visual and auditory cues, 7 times a week for 4 weeks (140 min a week)
Outcomes	Outcomes were recorded at baseline and at the end of intervention phase Unified Parkinson’s Disease Ranking Scale (UPDRS) Motor Score Freezing of Gait Questionnaire (FOGQ) 6‐min walk test (distance walked) Gait speed Stride length
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	method of sequence generation not described by the authors
Allocation concealment (selection bias)	Unclear risk	Not described by the authors
Blinding of outcome assessment (detection bias) All outcomes	High risk	all patients were assessed by same neurologist; no blinding described
Incomplete outcome data (attrition bias) All outcomes	Low risk	no missing outcome data