Tonight is the official start of the NFL season. It marks a day when an abundance of sports fans will unite to cheer on their respective teams; it also marks a day that multiple athletes will sustain bumps, bruises, and even devastating injuries.
The injuries can come from contact or no contact; from bone-shattering hits on receivers coming across the middle or from savage linebackers drooling for some contact. However, it is just as likely that a receiver runs a routine route, plants to make a sharp cut, and then falls to the ground in agony without being touched.
These non-contact injuries can occur in all sports and pickup games, from juking and jiving to avoid a collision on the street or sidewalk, and in any instance that requires the body to make a rapid eccentric contraction. An eccentric contraction is when a muscle lengthens under load, while a concentric is when it shortens. For example, in a bicep curl exercise, curling the weight up is the concentric, while lowering and controlling the weight to the start position is the eccentric.
Eccentric strength is vital for absorbing impact, decelerating, and changing directions rapidly. Eccentric muscle actions can produce more force than concentrics, specifically 50-80% more in single muscle fibers (Duchateau & Enoka, 2016). Because of this, more damage to the muscle can occur as well, especially in cases of instability caused by a lack of preparation for the movements you’re doing (running, jumping, cutting, etc.).
In a reactive and unpredictable sport which changes play-by-play, this eccentric stress can increase beyond the tolerance of the human body. Non-contact injuries often occur because the individual isn’t prepared to absorb that kind of stress. To combat this, you should practice in both controlled and uncontrolled environments. In the context of football, this means practicing drills to isolate and focus on specific techniques, and then testing them in game situations that are less predictable.
Let’s not forget either that there is no better way to absorb and adapt to stress than proper training. Both concentric and eccentric muscle actions are involved in the most basic of strength training exercises. More specific training methods such as plyometrics can be used too, which require a rapid eccentric or stretch, followed by a forceful concentric. An easy example of this would be jumping rope.
Nobody wants to be that guy in a pick-up basketball game that comes down from a rebound and collapses from a knee injury. Practice well and train smart to bulletproof your body from these non-contact injuries.
by Ross Curtis
1. Duchateau, J., & Enoka, R. M. (2016). Neural control of lengthening contractions. Journal of Experimental Biology, 219(2), 197-204.