Prognostic study, Level II.

Resistance to fatigue and muscle stiffness in the hamstring muscles may be risk factors for ACL injury in male soccer players. In addition, a predominant impairment in TMG characteristics of the quadriceps over hamstrings may indicate an altered muscular co-contraction (imbalance) between both muscle groups, which might be another risk factor for ACL injury in this population. These findings should be taken into account when screening athletes at high risk of ACL injury and also to design adequate prevention programs for ACL injury in male soccer players.

Therapeutic, Level II.

Neuromuscular characteristics in terms of mechanical and contractile properties of the gastrocnemius muscles may not be significant risk factors for ACL injury in male soccer players.

Prognostic study, Level II.