Corrective Exercises With Neuromuscular Electrical Stimulation In Children With Flexible Flatfeet

Ethics Statement This study was approved by the Institutional Review Board of the Faculty of Physical Therapy, Cairo University, Egypt (no. P.T.REC/012/0016370) and strictly adhered to the criteria proclaimed in the latest version of the Declaration of Helsinki code of ethics. Children's participation was commissioned by asking their legal guardian to sign a consent form prior to data collection.

Study design A prospective double-masked randomized controlled trial was carried out from September 1, 2018 to December 31, 2019 at the Out-patient Physical Therapy Clinic of Faculty of Physical Therapy, Cairo University.

Sample size estimation Sample size calculation was performed prior to the study using G*POWER statistical software (version 3.1.9.2; Franz Faul, Universitat Kiel, Germany) [F tests- MANOVA. Estimates of means of SAI were calculated from a preliminary study included 10 children who were assigned to the two treatment groups (5 children for each). Repeated measures, within-between interaction, α=0.05, β=0.2, Pillai V = 0.1, and large effect size] and revealed that the appropriate sample size for this study was not less than 65 children. ¬then, 70 children were recruited to account for the possible dropout rates.

Randomization Seventy-two volunteer children who were recruited from governmental schools at Cairo and Giza Provinces. The online Graph Pad software was used to allocate study participants to either intervention group (corrective exercise and NMES) control group (corrective exercise and placebo NMES). All children/legal and examiners were unaware of group allocation.

Inclusion criteria

The criteria for inclusion were

• Di¬agnosed (by an orthopedist) with asymptomatic FFF,
• Navicular height more than 9-millimeter (mm),
• Grade III flatfoot grade (midfoot width exceeding forefoot width)
• Normal body weight (BMI from 5th to 85th percentile),
• Presented with no neuromuscular or osseous anomalies.

Exclusion criteria

The authors excluded all children who had a history of

• Symptomatic flatfeet
• Congenital deformities of the lower extremities (e.g. genu valgum, femoral anteversion, leg length discrepancy, hypermobile joint)
• Scar/irri¬tated skin at the electrode placement
• Neurological/ neuromuscular disorders.