GAINESVILLE, Fla. -- When Florida coach Will Muschamp revealed that linebacker/end Ronald Powell had torn the ACL in his left knee in the Gators' April 7 spring game, he said Powell should only be out for 4 to 6 months.
It seemed a ridiculous prognosis. Athletes who suffer ACL tears are usually shelved from 6 to 9 months, and sometimes longer depending on the position and sport they play.
So to expect Powell -- an edge rusher who uses his speed and quickness to get to the quarterback -- to potentially cut that time in half seemed a little overzealous.
But in rare instances, it is possible to completely rehab a torn ACL injury in 4 to 6 months. It rarely happens, and there are certain criteria that must be met, but it's not out of the question that the 6-foot-4, 244-pound Powell could be on the field in mid-October.
"It is possible if everything goes perfectly," said Allen Weis, an athletic trainer at Preferred Physical Therapy in Fleming Island, Fla., with a master's degree in physical therapy. "I've seen it done. We've done it. But it's definitely in the minority."
Powell had surgery, in which his torn ACL was replaced with one from a cadaver, on April 23. Ten years ago, he would have automatically redshirted in 2012 and not participated in spring practice in 2013, either.
While he hasn't practiced with the team yet, he has been doing individual work on the side with coaches and trainers and showed off his mobility last Saturday during UF's lone open practice. He showed no signs of any trouble with his knee while doing agility drills and didn't limp at all when he jogged to the middle of the field to join the team meeting after practice.
Muschamp said he has been impressed with how Powell has attacked his rehab and Powell's positive attitude. Those two things are huge contributors in his quick recovery, Weiss said.
"There are so many factors that go into somebody's post-op recovery," Weiss said. "The time frame has been getting more and more aggressive as what we know and technology continues to progress and make things better. Somebody's individual motivation, somebody's work ethic, will all play a role."
It takes time to grow new blood vessels through the ligament and for the body to fully incorporate the ligament graft. Some people, though, do heal faster than others, especially if they're young, have no chronic illnesses or past injuries and don't smoke. But a general timetable for a typical athlete's rehab process, according to an article posted on About.com by Jonathan Cluett, a board certified orthopedic surgeon in Massachusetts, is as follows:
Range-of-motion exercises can begin right after surgery. Bicycle work and exercises to begin to strengthen the muscles around the knee are also used, Cluett writes.
As the knee grows stronger, the emphasis moves toward further strengthening the muscles around the knee and to balance in the 3-to-6-week range after surgery, Cluett writes. Once the range of motion has been completely restored and the swelling is gone, the athlete can begin sport-specific activities.
Athletes can begin light jogging and pool workouts sometime in weeks 7-12. However, Cluett writes that "side-to-side, pivoting sports -- such as basketball, soccer and football -- must be avoided." If the knee progresses well, some athletes can begin to do lateral exercises or drills.
By the fourth month, the athlete's rehab places greater emphasis on sport-simulating activities, Cluett writes.
This last phase of the rehab can take several months or longer, depending on how the knee responds. If there's swelling or if the athlete twists the knee while stepping off a curb, for example, the rehab timetable could be slowed or pushed back.
"There are certain things that as you go through the process that will be criteria-dependent," Weiss said. "That means when the athlete achieves A, we move to B. When they achieve B, we move to C. You can move through that faster or slower based on the patient's compliance and avoiding complications."
Even after the rehab is complete and the player has been cleared for full participation, though, there can still be one more hurdle to a complete recovery: trusting the knee completely. Ron Salazar, a physical therapist and athletic trainer at Jacksonville Orthopedic Institute, said that can take months, depending on the athlete.
"Everything's still tender and that graft is still really trying to become a part of the body," Salazar said. "Everything's still healing and sometimes it can take up to a full year where athletes are really feeling normal."
That's something that Powell will have to deal with whenever he is cleared to return to the field. It's looking more and more like that will be within the next month or so, which keeps him within the 4-6 month timetable that Muschamp gave two days after the injury.
"Everything has to go absolutely perfect," Weiss said. "… It is a tough thing to do, but it can happen."