Is strength alone enough to reduce the risk of injury?
Muscular strength is the ability to exert force to overcome external resistance. Research has shown that strength is vital for the normal function of daily activities and is associated with improvements in mortality (Ruiz et al, Philips, Fujita et al, Laukkanen, Heikkinen & Kauppinen). In short, the stronger you are, the longer you are likely to live, and with fewer health issues.
Strength training is often prescribed to aid in the prevention and rehabilitation of musculoskeletal injuries. The particular adaptations using resistance training to reduce injury are growth and/or increases in the structural integrity of ligaments, tendons, tendon to bone + ligament to bone junction strength, joint cartilage, and the connective tissue sheaths within the muscle. (Fleck, S. J. & Falkel, J. E.)
Decreases in muscle mass and the following reductions in muscle strength not only result in a loss of functional ability but also increases the risk for musculoskeletal injury. Many acute muscle strain injuries are thought to occur during the eccentric phase of sudden, forceful muscle actions.
A particular study from the Journal of Sports Medicine looked at the prediction of injury in American Football players, which are strong athletes with the ability to produce great amounts of force. Using the FMS, Functional Movement Screen, they found the players that could coordinate the movement test with the least competency and presented with asymmetries within joints, showed to be the highest risk of injury.
Quote from paper; “this study suggests that fundamental movement patterns and pattern asymmetry are identifiable risk factors for time-loss injury during the preseason in professional football players”
Another study using the Functional Movement Screen (FMS) looked at 433 firefighters, assessed their entry-level movement competency, and assigned a fitness program aimed to improve flexibility and strength in trunk stabilizer or core muscle groups showed incredible results.
The training program reduced lost time at work due to injuries by 62% and the number of total injuries by 42% over a twelve-month period. These findings suggest that core strength and functional movement enhancement programs to prevent injuries in workers whose work involves awkward positions are warranted.
So, is it lack of flexibility that made these stronger football players or firefighters score so low in the FMS?
There is plenty to read about when it comes to different athletes with various ranges of flexibility and the relating rate of injuries. An example would be that professional soccer players with tighter (than most) quads and/or hamstrings are more likely to have a muscular strain or tear throughout the season.
But then athletes that are classed “hyper-mobile”, or just have greater amounts of flexibility are at risk of joint-related injuries like ankle sprains (C. Decoster, N. Bernier, H. Lindsay, C. Vailas,)
Despite common opinion, several researchers have found that stretching does not reduce the risk of injury. Some of the results from the Strength and Conditioning journal conclude that stretching should most definitely be a part of every athlete’s training program but, no proof exists that stretching can reduce injury. If you look at the most commonly injured muscle, the hamstring, they found that the cause of hamstring strains was weakness in the muscle.
So yes, lack of flexibility can affect the FMS, but stretching may not improve it.
But if you are, for whatever reason, more flexible than the person next to you that doesn’t mean you’re less likely to get injured. A paper titled Flexibility and Its Effects on Sports Injury and Performance by G.Gleim, M.McHugh at Nicholas Institute of Sports Medicine and Athletic Trauma found that no conclusive statements can be made about the relationship of flexibility to athletic injury. Instead, specific flexibility patterns are associated with specific sports and even positions within sports. The relationship of flexibility to athletic performance is likely to be sport-dependent.
Instead, a lack of proper neuromuscular control seems to be the most significant risk factor for predicting injury.
We should be testing the quality of the movement patterns as an accurate predictor of injury risk. (D.Kolenia and J.Domaradzki)
Neuromuscular control is the ability of the nervous system to activate the correct muscles in the appropriate sequence with the right amount of force in ways that best match the goal we are trying to accomplish.
Past studies have shown that a major benefit to resistance training is learning to coordinate the different muscle groups rather than just increases in muscle strength. Suggesting that coordinated muscles are capable of smoothly decelerating joint actions even if the muscles themselves are weak.
It was the football players from the above study that had joint imbalances or asymmetries, or couldn’t coordinate/position their bodies to pass a good FMS score. The combination of flexibility training and core stability drills improved how the firefighters stabilized their bodies that improved their FMS score. Neither necessarily a strength nor flexibility issue.
Muscular strength is essential and will always remain so. But it seems to be that training to reduce the risk of injury has to include drills to improve muscle/joint coordination, mobility, proprioception, balance/stability, and complex movement patterns.
Would you like to learn a proven method to assess your client’s movement patterns with a systematic approach to training someone away from pain, injury, or dysfunction?
The Functional Training Institute’s Movement Restoration Coach (MRC) will provide you with all the tools and knowledge you need to become a fitness industry leader in injury prevention training.
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