Going into 2019, expectations for Buffalo Bills defensive end Trent Murphy have been tepid. His 2018 level of play was in stark contrast to his 2016 season where he made his presence known to the tune of a nine-sack season in Washington. Wanting to follow up on that performance, Murphy was dealt bad news when he suffered an ACL tear in the 2017 preseason. Since then, he has struggled to stay healthy and produce, leading to questions whether he was worth the contract he signed and if he will be a camp casualty. Despite sub-par play last season, there is reason to be optimistic for 2019.
During training camp in 2018, Murphy was nearly a year removed from the ACL tear. After coming off the left knee injury and finally cleared to practice, he suffered a minor groin injury that caused him to miss several practices early on. He was able to come back, re-injured the area, and ultimately missed most of the preseason.
Despite returning from his groin injury, Murphy’s injury issues were just beginning and he was banged up for a good portion of the season. They were as follows:
- Minnesota Vikings: R ankle injury as a result of getting rolled up on, did not miss the next game.
- Houston Texans: L ankle injury as a result of taking an awkward step, did not miss the next game.
- Indianapolis Colts: MCL sprain to R knee due to low block, missed 3 games.
- Detroit Lions: chest injury, did not miss the next game.
Looking at that injury history and the shortcomings he demonstrated throughout the season, that doesn’t lend much hope to 2019. However, there is optimism that leads me to believe Murphy will have a strong bounce-back year.
One of the key components of joint stability following ACL reconstruction is proprioception. This is the general awareness of position and movement of the body in relation to space. For example, the awareness to know if your arm is up in the air versus down to the side or knowing how to adjust to body position in order to stay upright during activities. This is sometimes considered the “sixth-sense” and something that we rely on constantly without ever truly being aware unless injury or impairment was to occur.
Getting more specific, proprioception is the ability to detect changes in tension, speed, acceleration, direction of movement, and the position of the joint. Within the ligaments that monitor for all these changes in motion is mechanoreceptors. These are sensory receptors in the body and found in ligaments that assist with providing feedback to the body in order to function properly with regards to motor function. This all takes place in a feedback loop, which means there’s constant input that can detect changes and alter the response immediately.
Regrettably, when the ACL is reconstructed with a new graft and mechanically corrected, there is a loss of those mechanoreceptors naturally found in the ligament if the remnants are totally removed. As a result, there is less feedback coming from the knee movement, which results in possible faulty movements or compensation patterns. This is similar to navigating in a well-lit area versus an area that is dark and unfamiliar. One may be able to move through a lit area without tripping, being extra cautious, or struggling to maneuver in the environment. In a dark area, there is little to no feedback such as sight, which results in awkward and unsafe movements due to not being able to self correct or prevent faulty movement as quickly.
Several studies support the notion that there is an initial loss of function and delayed recovery in regards to quadriceps strength and proprioception following the ACL surgery. There has also been research to support that the proprioceptive awareness continues to improve up to 3-4 years after the original surgery. We do know that the mechanoreceptors do eventually return to the area, which supports these studies. Despite these receptors returning to the tissue, this does not mean that the feedback loop will work immediately as it reintegrates into body functions. As a result, the surgically corrected joint may not operate as advertised despite being mechanically sound.
If you don’t have proper feedback on what the joint is doing, namely performing cutting motions which is why the ACL is so vital, other areas will compensate in order to pick up the slack. So as a result, you may see more hip or ankle injuries due to the body having to overcompensate for the loss of sensory feedback from the area during activity. Essentially, the body is seeing most of the picture, but not the full picture. Just like driving in snow, you may be able to clear enough ice off the window to drive, but you may miss what’s going on around you.
As a result, injury risks may be greater to other areas—which would not be ideal when trying to perform at peak levels. There is always the possibility that a tear to the new graft is possible as research has indicated that there is a 15-30% increase to re-tear following an ACL reconstruction for up to two years.
What it boils down to is Murphy is more fully healed than he was at this time last year and this will allow him to focus on more football tasks instead of the rehab that he was performing last year. As the proprioception of his knee improves, the quality of movement will continue to improve as the mechanoreceptors are restored. The efficiency of the feedback loop continues to improve leading to more purposeful movement with less thought and effort required. Simply put, practice makes perfect.
He can focus on the playbook knowing his knee and body can respond with greater ability and more fluid movement due to the improved neuromuscular control. In addition, he does not have to worry about learning a new defensive scheme, he doesn’t have to adjust to a new team, or focus on making sure he can return in time for the season.
Will we see a nine-sack season or better from Murphy in 2019? That I can’t predict, but his health shouldn’t be a factor, meaning he can focus on his craft. He will be stronger, healthier, and overall focused on proper football technique versus compensating during activities that could cause injury. I’m a big proponent of Murphy bouncing back this year. The reasons above state why he should, and I believe the Bills essentially got a steal in signing him last season. While he wasn’t as advertised initially, he should be able to grow into his role and take that next step towards turning the Bills’ defense into the monster that it can be.