The experimental group received a lecture session explaining what stretching is, its advantages and the importance of stretching in injury prevention. The specific intervention programme was to be performed at least 3 days/week (after training) for 12 weeks. These were static, active stretches of the muscles of the lower back, psoas iliacus, quadriceps, adductors, gluteus, hamstrings, and sural triceps. For each muscle group, the stretch was held for 60 seconds, divided into 3 repetitions of 20 seconds. Between each repetition, we did not return to the initial position but sought a new barrier to the stretch which would provoke the sensations described above. The total time dedicated to stretching was approximately 15 minutes per session.

The control group performed the initial and final assessments and continued to perform their team's standard/habitual stretches. To record whether they performed the stretches prescribed by the club, the researchers went to the end of the training unknown sessions and recorded whether the players performed them or not.

The stretching programme was to be performed at least 3 days/week (after training) for 12 weeks. These were static, active stretches of the muscles of the lower back, psoas iliacus, quadriceps, adductors, gluteus, hamstrings, and sural triceps. The final stretching position was that which generated a sensation of moderate-intense tightness in the muscles, but without exceeding the pain threshold. For each muscle group, the stretch was held for 60 seconds, divided into 3 repetitions of 20 seconds. Between each repetition, we did not return to the initial position but sought a new barrier to the stretch which would provoke the sensations described above. The total time dedicated to stretching was approximately 15 minutes per session.

This was measured with the "Fingertip-to-Floor Test"

It was measured with the Sideways Leg Splits test

The Leg Motion System was used.

The Passive Straight Leg Raise test was used, assessed qualitatively and quantitatively.

This was measured with the Ely Test

The Modified Thomas test was used, assessing the psoas qualitatively and quantitatively as well as indirectly the rectus femoris, the tensor fascia lata and the abductors.

It was assessed using the Sport Motivation Scale, validated in Spanish. This scale allows an objective assessment of the intrinsic, extrinsic and non-motivational factors of why children participate in their sport. In addition, the researchers added two questions related to motivation and stretching, to check whether the participants had correctly understood the importance of stretching.

Years

Female or male