Here is the design of a clinical trial:

Official Title: Determining the Optimal Dose of Reactive Balance Training After Stroke - a Pilot Study

Included conditions:
- Stroke

Study Armgroups:
- {'label': '1 session', 'type': 'ACTIVE_COMPARATOR', 'description': "Participants will complete one 45-minute session of reactive balance training. Participants will experience 40-60 perturbations during this session. Participants will also complete 5 45-minute 'traditional' balance training sessions.", 'interventionNames': ['Other: Reactive balance training']}
- {'label': '3 sessions', 'type': 'EXPERIMENTAL', 'description': "Participants will complete three 45-minute sessions of reactive balance training. Participants will experience 40-60 perturbations during each session. Participants will also complete 3 45-minute 'traditional' balance training sessions.", 'interventionNames': ['Other: Reactive balance training']}
- {'label': '6 sessions', 'type': 'EXPERIMENTAL', 'description': 'Participants will complete six 45-minute sessions of reactive balance training. Participants will experience 40-60 perturbations during each session.', 'interventionNames': ['Other: Reactive balance training']}

Interventions:
- {'type': 'OTHER', 'name': 'Reactive balance training', 'description': "A research physiotherapist will oversee reactive balance training (RBT) to ensure consistent RBT delivery across participants. Training strategies will be individualized to each participant, based on their balance impairments and rehabilitation goals. The RBT program includes multi-directional 'internal' and 'external' balance perturbations. Internal perturbations are achieved by asking the participant to complete tasks that challenge balance control, such that they lose balance when attempting to perform the task (e.g., kicking a soccer ball). External perturbation are delivered manually using a push or pull from the physiotherapist. As participants improve their reactive balance control, difficulty will be increased by shifting task requirements along a continuum from stable to mobile, and from predictable to unpredictable, and by increasing perturbation magnitude or imposing sensory or environmental challenges.", 'armGroupLabels': ['1 session', '3 sessions', '6 sessions']}

Primary Outcomes:
- {'measure': 'Rate of falls in daily life', 'description': 'Participants will be asked to report falls ("an event that results in a person coming to rest unintentionally on the ground or other lower level") in the 6 months post-training. Participants will be provided with stamped, addressed postcards to mail to the research team every 2 weeks for 6 months post-training. Postcards will contain a calendar, on which participants will record falls. The research assistant will call participants who do not return the postcard to determine if any falls occurred. The research assistant will contact participants reporting a fall to complete a short questionnaire determining the cause and consequences of the fall.', 'timeFrame': '6 months post-discharge'}

Please estimate the sample size based on the assumption: 
Pilot study recommendation
Sample size
        We will aim to recruit 12 participants per group (36 participants total), as recommended for pilot studies.38