Onychocryptosis is a pathologic condition of the nail apparatus in which the toenail damages the nail fold. It is a common condition provoking pain, inflammation, and functional limitation. It principally occurs in the hallux. Onychocryptosis is one of the most frequent complaints regarding the foot and accounts for many clinical consultations. The disorder has been classified in terms of the stages of the pathologic condition. In our practice, we discovered a clinical entity that was not previously classified in the literature. We classify onychocryptosis into stages I, IIa, IIb, III, and the new stage IV. A treatment plan is offered for each stage of this classification, with both general and specific indications given. In onychocryptosis treatment, it is important to select the surgical technique best suited to the patient’s particular clinical situation. (J Am Podiatr Med Assoc 97(5): 389–393, 2007)

Working on the intrinsic musculature of the foot has been shown to be effective in controlling pronation. However, the potential coadjuvant effect that involving other muscle groups might have on foot posture remains unknown. The aim was, therefore, to assess whether a 9-week intrinsic and extrinsic foot and core muscle strength program influenced foot posture in pronated subjects. The participants were 36 healthy adults with pronated feet that were randomly assigned to two groups. The experimental group (n = 18) performed a strengthening exercise protocol for 9 weeks (two sessions of 40 min per week), while the control group (n = 18) did not do these exercises. After 9 weeks, the foot posture index (FPI) scores of the two groups were analyzed to detect possible changes. The FPI at the baseline was 8.0 ± 1.5. After the 9 weeks, the experimental group showed significantly reduced FPI from 8.1 ± 1.7 to 6.4 ± 2.1 (p = 0.001), while the control group had the same score as pre-intervention (FPI 8 ± 1.2, p = 1.0). The FPI scores showed no significant differences by sex. Strengthening of the intrinsic and extrinsic foot and core muscles contributed to improving foot posture in adults, reducing their FPI by 1.66 points.