A comparative study between isolated gastrocnemius tightness patients and controls by quantitative Gait analysis and baropodometry

•Isolated gastrocnemius tightness has an influence on foot and ankle pathology.•Ankle dorsiflexion limitation inducing forefoot hyperpressure is the shared belief.•However Quantitative Gait Analysis shows only compensatory knee flexion. Isolated gastrocnemius tightness (IGT) has been suggested as an etiologic factor in mechanical disorders of the foot and ankle without a clear pathophysiological mechanism in the literature. We hypothesized that restricted ankle dorsiflexion inducing increased forefoot pressure in IGT patients could be this pathophysiological mechanism. Case/control experimental observational investigation. Forty lower limbs in 20 asymptomatic IGT patients were included and compared to controls. Quantitative gait analyses coupled with dynamic baropodometry were used for comparison between groups. The primary outcome was maximum ankle dorsiflexion during stance phase. Secondary outcomes were knee flexion and forefoot pressure. Maximum ankle dorsiflexion and maximum forefoot pressure were similar between groups. Increased knee flexion was found in the asymptomatic IGT group. IGT induced compensatory knee flexion during stance phase, which probably prevents increased pressure on the forefoot by allowing ankle dorsiflexion. Level IV, Case/control experimental observational investigation.