With the Philadelphia 76ers’ recent 130-103 victory against the Miami Heat in game one of the NBA Eastern Conference playoffs, and the return of Markell Fultz, who had been sidelined for much of the regular season with a scapular muscle imbalance, it’s a great time to talk about sports-related shoulder injuries and the often overlooked but ever-important concept of the friend or foe that is muscle memory.

As the No. 1 pick in the 2017 NBA draft, 19-year-old Markelle Fultz was widely-regarded as the nation’s best collegiate player and to be in serious contention for the NBA’s Rookie of the Year honor. But in October and just four games into his rookie season, all of that promise hung in the balance when he was benched indefinitely due to a sustained shoulder injury – called a scapular muscle imbalance. Though the cause of the injury remains much of a mystery, Fultz’ struggles with mechanics and proper form were obvious. Observing his shooting form during his rookie NBA season and comparing it to his collegiate basketball days at the University of Washington, there are clear differences in his mechanics.

The truth is, scapular muscle imbalance injuries and those like them don’t arise out of thin air. Unlike an ACL tear, for example, which is usually the result of an acute, identifiable injury, scapular muscle imbalance refers to asymmetrical shoulder blades – a painful condition that is typically caused by overuse on one side and leads to an abnormal movement pattern. In a nutshell, this isn’t one of those sports injuries that happens all of a sudden, but over time. And a significant factor involved in sustaining a scapular muscle imbalance injury is something called muscle memory.

Muscle memory is a term that describes how we are able to master complex motor skills through practice and repetition. By simply repeating the exact same muscle movements over and over again, like when shooting a basketball, precise patterns of muscle coordination are established in the brain and become automatic to the body. NBA players like Fultz rely on thousands of hours of practice to establish proper technique and form. They develop and store muscle memory which propels them forward as the level of competition increases. However, when an NBA star decides to significantly alter his shot mechanics, he essentially erases any prior muscle memory created by those thousands of hours of prior practice and replaces it with memory of the new technique.

But here is the problem – this newly established muscle memory may actually be counterproductive and can lead to poor performance or injury. There are 17 muscles that attach to the scapula (shoulder blade). Shooting a basketball is a complex motor task involving nearly all of those muscles as well as others. Even minor changes in shooting form can throw off the delicate muscle balance and motor coordination, resulting in the risk of sustaining significant injury. When muscle memory has been created with poor form or improper technique, it causes the repetition of technical mistakes that can lead to injury again and again. In effect, you build muscle memory with those mistakes and become really good at a bad, injury- causing technique.

To regain proper muscle memory, significant time is often necessary to rewire, retrain and restore accurate form. This, coupled with time to feel ready enough to return, is perhaps the most significant reason it took Markelle Fultz more than five months to return to play. While only time will tell whether Fultz has made the adjustments necessary to restore solid technique, I look forward to seeing him realize his fullest potential back out on the court.