Vertical ground reaction forces during gait in children with and without calcaneal apophysitis

•Loading patterns during gait were examined in children with calcaneal apophysitis.•Vertical ground reaction force peaks did not differ to healthy children during gait.•Peak regional plantar pressures beneath the foot did not differ to healthy children.•Children with calcaneal apophysitis had a higher cadence, particularly when running.•Higher cadence may be used to regulate loading patterns in calcaneal apophysitis. Heightened vertical load beneath the foot has been anecdotally implicated in the development of activity-related heel pain of the calcaneal apophysis in children but is supported by limited evidence. This study investigated whether vertical loading patterns during walking and running differed in children with and without calcaneal apophysitis. Vertical ground reaction force, peak plantar pressure (forefoot, midfoot, heel) and temporospatial gait parameters (cadence, step length, stride, stance and swing phase durations) were determined in children with (n = 14) and without (n = 14) calcaneal apophysitis. Measures were acquired during barefoot walking and running at matched and self-selected speed using an instrumented treadmill, sampling at 120 Hz. Statistical comparisons between groups were made using repeated measure ANOVAs. There were no significant between group differences in vertical ground reaction force peaks or regional peak plantar pressures. However, when normalised to stature, cadence was significantly higher (≈ 5%) and step length shorter (≈ 5%) in children with calcaneal apophysitis than those without, but only during running (P