A six-month unsupervised training program does not improve ankle joint mobility in soccer players

Problem Statement: Soccer practice can induce marked changes in ankle joint mobility (AJM) with dreaded consequences related to the quality of balance, posture and gait. Moreover, a limited ankle range of motion may represent an important risk factor for injuries and negatively affect performance. Purpose: The aim of this study was to evaluate the effects of a stretching training protocol (STP) on the AJM of adult male soccer players (SP). Material and Methods: 34 amateur male SP (age 29.0±4.6 years) and 24 non-soccer players (control group) matched for age, gender and BMI were included in this study. In both groups AJM and muscle strength were evaluated by inclinometer and Jamar hydraulic hand dynamometer respectively. Moreover, data on sports practiced, years of activity, history of injuries, dominant kicking leg, and presence of athletic trainers were collected. SP group performed six months of a STP that included 4 exercises aimed at improving AJM. Due to the Covid-19 pandemic the STP was suspended for 4 weeks in the middle period of the study. Results: At baseline, SP group showed reduced AJM compared to controls (116.1±13.1° vs. 137.7±13.6; p<0.001) while muscle strength was similar (45.0±7.5 vs 48.0±8.9 kg). STP produced a non-significant effect on AJM (116.1±13.1 vs 116.8±15.1°). No differences were found between the two groups considered as regards the difference in mobility between the two ankles (right vs left; dominant vs non-dominant). Considering the initial values, there was a direct correlation between HS and BMI (r=0.38; p<0.025), while AJM showed an inverse correlation with years of activity (-0.36; p<0.037). No correlation was found between hand grip test and AJM. Conclusions: SP showed a significant reduction in AJM which was difficult to recover even following a STP. The interruptions of sport activity due to the Covid-19 pandemic and the absence of athletic trainers in the sports clubs involved, in addition to the long history of soccer practice could justify, at least in part, the results obtained