Here is the design of a clinical trial:

Official Title: Efficacy of Combined Low- and High- Frequency Stimulation in Peripheral Muscle Function During Hemodialysis

Included conditions:
- Chronic Kidney Diseases

Study Armgroups:
- {'label': 'Active comparator', 'type': 'EXPERIMENTAL', 'description': 'Low frequency electrical stimulation for 60 minutes, three times a week during 60 days.', 'interventionNames': ['Device: Electrical stimulation']}
- {'label': 'Other', 'type': 'EXPERIMENTAL', 'description': 'High frequency electrical stimulation for 60 minutes, three times a week during 60 days.', 'interventionNames': ['Device: Electrical stimulation']}
- {'label': 'Experimental group', 'type': 'EXPERIMENTAL', 'description': 'Low and High frequency electrical stimulation for 60 minutes, three times a week during 60 days.', 'interventionNames': ['Device: Electrical stimulation']}
- {'label': 'Placebo', 'type': 'PLACEBO_COMPARATOR', 'description': 'Placebo electrical stimulation for 60 minutes, three times a week during 60 days. In the intervention groups will be used highest intensity tolerated by the individual, and in the sham will be maintained the minimum intensity after beginning of the perception of the electric current', 'interventionNames': ['Device: Electrical stimulation']}

Interventions:
- {'type': 'DEVICE', 'name': 'Electrical stimulation', 'description': '1) Low frequency electrical stimulation (LF) ; High frequency (HF); Low and High frequency (LHF) ; and sham stimulation. Groups will receive bilaterally electrical stimulation, for 60 minutes, three times a week, during two months.', 'armGroupLabels': ['Active comparator', 'Experimental group', 'Other', 'Placebo'], 'otherNames': ['Low frequency electrical stimulation (LF)', 'High frequency (HF)', 'Low and High frequency (LHF)', 'sham stimulation']}

Primary Outcomes:
- {'measure': 'Assess the improvement of muscle mass', 'description': 'The muscle mass will be assessed by electric bioimpedance', 'timeFrame': 'Eight weeks'}
- {'measure': 'Assess the improvement of muscle strength', 'description': 'The muscle strength will be assessed using isokinetic by peak torque', 'timeFrame': 'Eight weeks'}
- {'measure': 'Assess the improvement of muscle resistance', 'description': 'The muscle resistance will be assessed using isokinetic by fatigue index', 'timeFrame': 'Eight weeks'}

Please estimate the sample size based on the assumption: 
Significance level of 5% and statistical power of 80%
Sample size
        The sample size calculation was performed using a statistics programme (SigmaStat V.3.5; San Jose, California, USA), based on the results obtained by Dobsak et al,10 who found, in the group that performed NMES, a baseline value of peripheral muscle strength of 185.4Â±53.0âkgf and a post-treatment value of 222.4Â±36.6âkgf. Considering an error of 5% and statistical power of 80%, a sample size of 14 patients in each group will be necessary, totalling the inclusion of 56 patients.