This may very well be a sensible way, but the use of explicit strategies may be less suitable for the acquisition of the control of complex motor skills [34]. It has been shown that instructions that direct performers’ attention to his or her own movements can actually have a detrimental effect on performance and learning and disrupt the execution of automatic skills, particularly in comparison with an externally directed attentional focus [33, 37, 67–69]. We want to emphasize that we need to make sure that a better landing technique after a jump happens automatically. Therefore, pre-programming with automatization with transfer for laboratory to field is most important.

The exact reasons for the beneficial effects of an external focus of attention are still relatively unclear. However, trying to consciously control one’s movements might interfere with the normal, automatic motor control processes, leading to a breakdown in the natural coordination of the movement [32, 37].

The performance and learning of motor skills has been shown to be enhanced if the performer adopts an external focus of attention (focus on the movement effect) compared to an internal focus (focus on the movements themselves) [68]. In other words, implicit motor learning refers to the acquisition of a motor skill without the concurrent acquisition of explicit knowledge about the performance of a skill that is normally processed in an automatic way, explicit motor learning does refer to acquiring motor skills with an internal focus and specific knowledge about the performance of a skill [34]. Motor skills that are acquired explicitly tend to be less resilient under psychological [7, 18, 19, 32, 39] and physiological fatigue [31, 54], tend to interfere with the normal automatic processing of the motor schema [20, 32], tend to be less durable [5] and less robust [66] when a fast response is required and explicit learning may be affected to a greater extent by an individual’s intelligence than implicit learning [17, 45, 57].

Considering the benefits of implicit learning, we feel that in the prevention of ACL injuries, we need to discover the possibilities of this method as it may produce more stable solutions under stress, anxiety-provoking conditions and fatigued states. The research group McNair, Onate and Prapavessis set up an interesting series of research projects, in which they examined the effect of different types of feedback on jump landing technique and subsequent landing forces [36, 49, 50, 55, 56]. The patterns shown in their results confirmed the theory mentioned earlier. They have compared technical instructions, visual feedback, auditory cues, and metaphoric imagery to controls. They first found that subjects can assimilate precise instructions related to the modification of lower limb kinematics and effectively and immediately lowered their ground reaction forces (GRF) [36, 50, 55]. However, in 2003 Prapavessis et al. found that the retention of these technical instructions is poor when the follow up is longer than 1 week [56]. Continuing this research, Onate et al. concluded in 2005 that reviewing one’s own performance or one’s own performance plus an expert model is more useful than expert only modeling (i.e., viewing an expert model trained in proper landing technique) for increasing knee angular displacement flexion angles and reducing peak vertical GRF during landing. They therefore suggested that visual feedback of one’s own performance or one’s own performance plus an expert model should be used in the implementation of instructional programs aimed at reducing the risk of jump-landing ACL injuries [49].

In the ACL injury enigma, psychological and physiological pressure or fatigue is an important factor. Myklebust et al. reported that athletes are at a higher risk of suffering an ACL injury during a game than during practice [43]. Fatigue has also been proposed to be a contributor to non-contact ACL injuries [24, 47, 61]. For obvious reasons, a game constitutes more psychological and physiological stress compared to a practice session. Especially in later stages of competition, fatigue may have a cumulative, unfavorable effect on neuromuscular control and may potentially result in hazardous movement strategies [35]. The decreased capacity for controlling body movements after fatigue will potentially be more prominent when appropriate landing techniques have been taught in an explicit manner. Also, the possibility that implicit learning may immunize the athlete more against the often debilitating influence of psychological stress on motor output should not go unheeded.

Preventive studies we have referred to in this article mostly contain exercises that improve performance and reduce injuries by improving strengthening and conditioning. From these investigations, we have learned that ACL injuries can be prevented by a combination of balance/coordination, strength, plyometric and agility exercises [3, 4]. Immediate feedback of someone’s own performance is an area which is still relatively unexplored and can aid in achieving long term results.