The Influence of Age on the Effectiveness of Neuromuscular Training to Reduce Anterior Cruciate Ligament Injury in Female Athletes

Abstract

Background In female athletes, sports-related injuries to the anterior cruciate ligament (ACL) increase during adolescence and peak in incidence during the mid- to late teens. Although biomechanical investigations indicate that a potential window of opportunity exists for optimal timing for the initiation of integrative neuromuscular training (NMT) in young female athletes, the influence of the timing of initiation of these programs on the efficacy of ACL injury reduction has yet to be evaluated. Hypothesis/Purpose The purpose of the current report was to systematically review and synthesize the scientific literature regarding the influence of age of NMT implementation on the effectiveness for reduction of ACL injury incidence. The hypothesis tested was that NMT would show a greater effect in younger populations. Study Design Meta-analysis; Level of evidence 1a. Methods Data were pooled from 14 clinical trials that met the inclusion criteria of (1) number of ACL injuries reported; (2) NMT program used; (3) female participants were included; (4) investigations used prospective, controlled trials; and (5) age of participants was documented or was obtainable upon contact with the authors. A meta-analysis with odds ratio (OR) was used to compare the ratios of ACL injuries between intervention and control groups among differing age categorizations. Results A meta-analysis of the 14 included studies demonstrated significantly greater knee injury reduction in female athletes who were categorized in the preventive NMT group compared with those who were in the control group (OR: 0.54; 95% confidence interval [CI]: 0.35, 0.83). Lower ACL injuries in mid-teens (OR 0.28; CI: 0.18, 0.42) compared with late teens (OR 0.48; CI: 0.21, 1.07) and early adults (OR 1.01; CI: 0.62, 1.64) were found in participants undergoing NMT. Conclusion The findings of this meta-analysis revealed an age-related association between NMT implementation and reduction of ACL incidence. Both biomechanical and the current epidemiological data indicate that the potential window of opportunity for optimized ACL injury risk reduction may be before the onset of neuromuscular deficits and peak knee injury incidence in female athletes. Specifically, it may be optimal to initiate integrative NMT programs during early adolescence, before the period of altered mechanics that increase injury risk.

Long-Term Athletic Development, Part 2

“…Therefore, given the recent decline in both of these fitness parameters, any long-term strategy should prioritize the development of muscle strength and motor skill proficiency during the primary school years. It is imperative that youth engage in training modalities to develop muscular strength and fundamental movement skills in early childhood to maximize their modifiable neuromuscular systems (28,92). These evidence-based guidelines challenge previous athletic development models (8) and counter preconceived concerns surrounding structured resistance training for children.…”

“…Recently, researchers have proposed that for those athletes who have specialized in a single sport at an early age, physical training should concentrate on enhancing generic movement skills and addressing muscle weakness or imbalances ( 5 9), instead of being exposed to sport-specific performancedriven training. Providing progressive and mul-tifaceted training opportunities for such athletes to develop more fundamental movement skills may overcome the propensity for early specializing athletes to be at increased risk for a sports-related injury, illness, or burnout (45,92). It is accepted that not all acute injuries are unavoidable in sport; however, practitioners should be cognizant of risk factors that may predispose youth to overuse injuries.…”

“…During childhood, the neuromuscular system is highly "plastic" (33,92) and is amenable to adaptation owing to the peaking of brain maturation rates (6-8 years and 10-12 years) ( 10 3), synaptic pruning ( 15), and overall strengthening of the synaptic pathways (16). It has also been established For young children entering sport(s) development pathways, focus should be geared towards preparatory conditioning and fun-based activities, with a reduced focus on competitive fixtures.…”

Strength Training and Metabolic Conditioning for Female Youth and Adolescent Soccer Players

“…Integrative neuromuscular training is ideally initiated in early adolescents with the most profound effects occurring at younger ages (41,42). Training pre-PHV should aim to improve neuromuscular strength, fundamental movement skills, and speed (30).…”

Prevention and rehabilitation of paediatric anterior cruciate ligament injuries

“…ACL injury prevention using neuromuscular training is highly successful in the adolescent population [48]. Swart et al [62] also concluded these programmes are cost-effective.…”