Randon Hall, MD
The Grip Explained - Marcus Mariota's Ulnar Nerve Injury
Week 1 of the 2018-2019 season, Tennessee Titans Quarterback sustained and elbow injury to his throwing arm. Further reports confirmed that he was having difficulty gripping the ball normally due to a ulnar nerve (funny bone) injury. He did not return week 2 of the season, and at publishing of this article his return is still unclear. We are going to take a meticulous look at this ulnar nerve injury and understand how it impacts his ability to grip the ball and the consideration for return to play.
The ulnar nerve runs on the inner aspect of your elbow and is commonly known as the funny bone. It is susceptible to blunt force trauma, because the nerve runs very close to the skin and does not have much soft tissue protection. Mariota sustained a direct impact to the elbow causing a contusion to the nerve resulting in both weakness and numbness in the hand. In order to understand how this injury is impacting his grip, we have to understand the normal function of the ulnar nerve in both movement and sensation.
Function # 1 - Bringing the Fingers Together
Function # 2 - Spreading the Fingers Apart
Function # 3 - Bending at the Knuckle of Ring and Pinky Finger
Function # 4 - “Flexing” the Thumb (Adduction)
Function # 5 - Pinching Grip
Function # 6 - Sensation to Pinky and Half the Ringer Finger
Biomechanics of a Grip
Initially, injury to the ulnar nerve at the elbow will cause weakness or loss of motors function listed above. In addition, injury to the nerve at the elbow will cause tingling or numbness of the same fingers. Let's looks at things from a functional functional perspective. In addition to the other nerves that are working well, he will need functions # 2, #3 & #6 for grip and to take the ball under center, as well as #5 in the shotgun. He will need at least # 1, #4 and #6 to properly release the ball. Therefore his ability to grip normally and release a proper spiral is essentially impaired. The extent of the deficits to those fingers will be directly related to the extend on the nerve injury. Unfortunately for Mariota, there may be elbow pain radiating to the hand, and symptoms may be worse with prolonged or repetitive throwing motion.
Likelihood he will play
The most difficult part of the whole situation is that there is not much that can be done to expedite the healing process. If a nerve is stretched then the function usually will return to baseline shortly, minutes to hours. If the nerve is truly damaged then the function may take days to weeks to return to normal as the nerve is very slow to heal itself. The main treatment is anti-inflammatory medications such as ice, NSAIDs or Prednisone to treat inflammation, yet that will not impact the speed of the nerve recovery that has been damaged. To make matters worse, Mariota will be at high risk for re-injury and will likely have to wear a elbow sleeve or pad on his throwing arm. I think his training staff will find a way to get him back sooner rather than later, but the question is will he be at full strength in the passing game. I predicted he will miss 1-2 weeks and that remains to be seen. For now all he can do is sit and wait for the feeling and strength to return.