Abstract

Background: Unexplored in individuals with flatfoot (FF) is the potential of foot specific exercise and barefoot weightbearing (BWB) to improve foot function. The purposes of this study were

A. To evaluate whether exercise and BWB alter foot muscle structure in participants with FF

B. To evaluate whether exercise and BWB alters foot and ankle function in participants with FF

C. To compare foot muscle structure and foot and ankle function between participants with FF to controls with neutral foot posture prior to exercise.

Methods: Twenty participants with FF and 12 participants with neutral foot posture participated.Participants with FF completed 8 weeks of 4 foot exercises and 2 hours of BWB.Pre and post-exercise tests included:

A. Diagnostic ultrasound to quantify abductor hallucis cross sectional area (CSA)

B. Embedded force plates to assess paper grip test (PGT) force

C. Heel rise height and repetitions

D. The Foot and Ankle Ability Measure (FAAM), and qualitative data to capture potential benefits post-exercise.Control and FF data was compared pre-exercisewith independent t-tests.

Two-way repeated measures ANOVA’s were used to compare participants with FF pre and post-exercise.The effect size index (ESI) was used to note the degree of improvement.

Results: Participants with FF significantly improved in all variables except the FAAM. Muscle CSA increased from 0.27cm2 to 0.35cm2, a 12.9- 16.7% increase (P< 0.05).The PGT showed increased force post-exercise from 13.2N to 13.7N (P< 0.05). Post-exercise heel rise repetitions increased from 7.1-7.6 repetitions (P< 0.05).Compliance was 87.7% of prescribed exercises and 111% of time targeted for BWB.

Conclusion: Foot specific exercises and BWB achieve sufficient training intensity to result in changes in foot function. The study confirms that training effects specific to the foot are achievable in participants with FF, and likely to patients with foot problems.

Keywords: Flatfoot; Exercise; Heel rise; Abductor hallucis; Paper grip test; Barefoot

Abbreviations: FF: FlatFoot; BWB: Barefoot Weight Bearing; PGT: Paper Grip Test; ESI: Effect Size Index; FAAM: Foot and Ankle Ability Measure; FPI: Foot Posture Index; CSA: Cross Sectional Area;MTP: First MetaTarsophalangeal Joint; CP: Control Participants; BMI: Body Mass Index