Optimizing Rehabilitation: The Impact of Encouragement and Instruction on Return-to-Play and Injury Risk Assessment

Day 1: After an explanation of the test development, informed consent will be obtained. Subsequently, anthropometric assessments will be carried out. The placement of the electrodes will be done according to standardized locations for electromyography (EMG) measurements of the target muscle groups in accordance with SENIAM guidelines. Then, participants will complete a standard warm-up (mobility drills, 5' bike at moderate intensity) Finally, a familiarization session with the equipment and test procedures will be conducted. Assessment will be carried out for differents researcher blinded who only know what they have to apply. Experimental conditions (CE) will be the next for all participants: ENCOURAGE: only the participant will be encouraged to make maximum force production. (i.e "go,go,go) EXPLICIT LEARINING: the instruction is intended to focus the participant's attention on producing strength with the specific musculature. (i.e "push with your quad") ANALOGY LEARNING: the instruction is intended for the participant to think of a similar situation so that he creates a mental representation of the situation and his force production is oriented to it. (i.e "imagine that someone is grabbing you to keep you from moving. try to free yourself.") CONTROL CONDITION: you are described how to do the test simply "i.e. you have to extend the knee and flex". Day 2: The second visit will begin with a brief warm-up in an attempt to replicate the physiological conditions of the first visit. The electrodes will be repositioned to ensure data collection consistency. The testing phase for hip extension will start with a Maximum Voluntary Contraction (MVC) following Konrad 2005 guidelines. After a control condition, the randomized order of experimental conditions will be followed using specialized software. This sequence will then be replicated for CE1, CE2, and CE3 conditions. Three maximum repetitions will be performed. The isokinetic knee extension test will also follow the MVC > CEcontrol order, with randomization for the other 3 CE conditions. The speed will be set at 60°/s, and 3 repetitions will be performed to ensure adherence to instructions and prevent participants from generating their own rules. The rest period between experimental conditions will be 10 minutes with the aim of reducing post-activation potential and fatigue resulting from the test contractions. Afterthat, will be carried out the same protocol in a hip extension exercise (lying the participant in a supine position with extension during a maximal isometric contraction) Time aproximation of the session will be 1 hour and half. Mode of administration will be a one-on-one visit to the laboratory. EMG during isokinetic knee extension will be assess over quad muscles and for hip extension test, semitendinous, major gluteus and erector spinae L1 level will be assessed.