Use of questionnaire for monitoring soccer players' recovery and its impact on injury risk

Introduction In modern day soccer, player’s injury related lost playing time is a taxing event for both athletes and teams. Thus, a broad array of injury prevention strategies (1) and injury prediction models (2) have been proposed. Monitoring player’s recovery status is one of those strategies that, despite being an intricated and yet a questionable process, can give precious information on athletes’ readiness to play and possibly prevent future injuries. The purpose of the present study was to assess whether a multi item questionnaire rating recovery could detect increased risk of injury in professional male soccer players. Methods Participants involved in the present study were 20 male professional Italian soccer players (age 22±5 years, height 1.81±0.05 m, weight 72±4 kg). Among those, 9 were selected for further analysis due to incurrence of acute non-traumatic injury after at least 4 weeks of training. To monitor recovery six different items (sleep, stress, fatigue, soreness, appetite and motivation) were scored(S) with via a visual analogic scale ranging from 1 to 5 (3). A global index of recovery (R) was computed with this formula: Σ0i(Si×Wi)/25, where W is a weighting factor different for each S (0.4, 0.4, 1.2, 1.0, 1.0, 1.0 respectively) and 25 is the maximum sum that could be achieved. The result was a number between 0.2 and 1.0 where 1.0 meant a perfect recovery (3). Data were grouped by week backwards from injury date. A statistical approach based on the magnitude of the changes was used to examine practical significance of each S, R and R’s standard deviation (Rsd) for up to 4 weeks before the injury. A clinical inference, based on threshold chances of harm and benefit of 0,5% and 25% was used to evaluate the chances of a beneficial or harmful effect. Results R does not vary between injury’s week and previous weeks, while Rsd undergoes a variation in the weeks leading to injury: it can be inferred a likely harmful effect (0.5±0.77) (mean±90%C.I.) for the week -1 and possibly harmful effect for week -2 and week -3 (0.31±1.02 and 0.37±0.90 respectively). Analysing single items in the questionnaire the only changes were reported for Fatigue and Soreness, being Fatigue possibly harmful for week-1, week-2 and week-3 (0.17±0.76, 0.26±0.90, 0.32±0.81) and fatigue very likely Beneficial for week -1 (-0.35±0.97), while no changes were seen for the remaining four items. Conclusions The weeks leading to an injury for the players included in the study were characterised by a progressive reduction in Rsd, this signifying a more homogeneous content for injury’s week on previous weeks. Fatigue and Soreness underwent alterations in opposite directions: the first increased while the latter underwent to a reduction from the weeks preceding the event to injury’s week. This discovery opens a meaningful insight on the interaction standing between different items score, that should be further investigated broadening the number of participants and weeks leading to injury.References 1. Mccall A, Carling C, Legall F, Berthoin S, Dupont G. Recovery in Soccer. 2012;42(12):997–1015. 2. Hulin BT, Gabbett TJ, Lawson DW, Caputi P, Sampson JA. The acute:chronic workload ratio predicts injury: high chronic workload may decrease injury risk in elite rugby league players. Br J Sports Med [Internet]. 2016;50(4):231–6. Available from: http://bjsm.bmj.com/lookup/doi/10.1136/bjsports-2015-094817 3. Bahnert A, Norton K, Lock P. Association between post-game recovery protocols, physical and perceived recovery, and performance in elite Australian Football League players. J Sci Med Sport [Internet]. Sports Medicine Australia; 2013;16(2):151–6. Available from: http://dx.doi.org/10.1016/j.jsams.2012.05.008