The title hopes of the Oklahoma City Thunder took a significant hit Friday when it was revealed power forward Serge Ibaka suffered a Grade 2 plantaris strain in his left leg. This little known muscle is tiny in size but can prove to be very problematic.
The plantaris is situated on the posterior aspect of the leg, just below the knee. The muscle itself sits just below the outside portion of the gastrocnemius, one of two muscles that make up the calf. From there its long tendon runs the course of the leg. In most cases this tendon conjoins with the tendons of the two calf muscles to form the Achilles tendon. However an anatomical study has shown that the plantaris can connect to the heel independently of the Achilles.
Functionally the plantaris is not very active. It does aids the gastrocnemius while bending the knee (flexion) and pointing the foot (plantar flexion) but in a very minimal way. This may confuse frustrated Thunder fans but the plantaris plays another role that may be more important to Ibaka’s long-term health.
The plantaris is regarded as a muscle of proprioceptive function. Proprioception is an individual’s overall awareness of the position of the body or a joint during motion. It is a key component of joint stability as the brain is able to process conscious and unconscious information to coordinate proper movement. Information for proprioception is provided by proprioceptors located in skeletal muscle tissue. The plantaris muscle is heavily saturated with proprioceptors, which help manage fluid motion at both the knee and ankle. Damage to the muscle would not only be particularly painful but could affect the overall integrity of the involved joints.
As previously mentioned Ibaka’s injury was diagnosed as a Grade 2 strain, meaning the sprain is considered moderate with partial tearing occurring at the muscle belly or tendon. Ibaka is likely functionally limited and would be susceptible to a complete tear if he attempted to play through the pain. The timeline provided by the Thunder is in line with the other documented examples of plantaris injuries in the NBA. Since the 2007-08 season there have been five reported case of plantaris injuries. The average number of games missed for these incidences is 16.4 games. While the sample size is small only Tiago Splitter returned in fewer than 10 games and his injury occurred in the preseason and was considered less severe.
In a season marred by injury, the Oklahoma City medical staff remained one of the best in the league. However timing is everything and the team is left without one of their top players for the second straight postseason. The Thunder will need an inspired team effort to take down the Spurs but even a return to the Finals won’t guarantee Ibaka’s return.