The Fear Doesn’t Show Up on the Tests

The SparkNotes

• Fear of reinjury is cited as the single most common reason athletes do not return to sport after ACL reconstruction.

• In 27 athletes already cleared to return, high-fear and low-fear groups differed on only two of the physical measures tested.

• Strength, balance and hop symmetry showed no meaningful difference between them.

• The likely reason is that the most fearful athletes never make it into a study of athletes who returned.

• Twenty-seven people. Read it as a signal to ask a question, not as a finding to act on alone.

The Whole Story

Ask why athletes do not go back to their sport after an ACL reconstruction and the most common answer is not pain, and not strength.

It is fear of doing it again.

So a group of researchers asked an obvious follow-up question. If fear is that powerful, does it show up in the physical tests used to clear people?

What they did

Twenty-seven athletes, all within two months of being cleared to return to sport after an ACL reconstruction. Each completed a standard fear-of-movement questionnaire, and the group was split into higher-fear and lower-fear halves.

Then both groups were compared across the things a return-to-sport battery actually measures: strength, balance, jump-landing mechanics, and hop test performance.

What they found

Almost nothing.

Of everything tested, only two measures differed significantly between the higher-fear and lower-fear groups: ankle flexibility, and how much the knee collapsed inward during a jump-landing task.

Strength — no meaningful difference. Balance — none. Hop test symmetry, the number most commonly used to sign people off — none.

The average fear score across the whole group was also fairly low compared with the thresholds other research uses to define clinically meaningful fear of movement.

The explanation, and it is better than the result

The authors' leading interpretation is a selection effect, and once you see it you cannot unsee it.

The athletes with genuinely high fear of reinjury may simply not return to sport. Which means they never appear in a study of athletes who have been cleared and are going back.

So this is not evidence that fear does not matter. It is evidence that by the time someone has reached the point of being cleared, fear is no longer a strong predictor of how they will physically perform — because the people in whom it mattered most are not in the room.

The finding is shaped by who was available to study. That is worth understanding as a general habit when reading anything about return to sport.

The honest size of this

Twenty-seven athletes. The authors themselves caution that the results should be interpreted carefully given both the sample size and the low fear scores in this particular group.

So this is not a study that should change a protocol. It is a study that should change a question.

What this looks like in the clinic

An athlete is almost always going back to the exact movement, activity or sport that injured them in the first place. So the psychological side of this is real, and it shows up across every kind of injury and pain — not just ACLs.

How you handle it depends entirely on the athlete and on the relationship you have with them. Some need to see the data — force plate numbers, video of their own movement — before they will believe the leg can do it. Others need to talk it through, and say out loud what makes a movement hard, mentally or physically.

Then you break the movement into parts. Practice, practice, practice, and retest. Start slow, simple and controlled, and build toward fast, complex and chaotic — unanticipated movement, distractions, game-like scenarios — because sport is chaotic, and eventually rehab has to be too.

Physical readiness usually arrives before psychological readiness. That is normal, and it is common. It is also something that can be worked on rather than waited out.

What it changes in practice

• Physical readiness and psychological readiness are not the same thing, and passing one does not tell you much about the other.

• Fear needs its own assessment. It does not reliably surface in strength or hop testing, so somebody has to actually ask.

• And the people most affected by fear may be missing from the research on it, which means the true picture is probably worse than what the studies show rather than better.

If you have been cleared and something in you still does not want to plant and turn on that leg, that is not a character problem and it is not something to push through quietly. It is a separate part of the recovery that has its own assessment and its own work.

Follow along as Resurgo comes together.

Read next: Cleared to Play Isn't the Same as Ready to Compete · What Happens After You're Discharged?

SOURCE: Lennon AR, Faherty MS, Killelea C, Le DT, Sell TC. An Examination of the Relationship Between Fear of Reinjury and Neuromuscular, Musculoskeletal, and Biomechanical Characteristics at the Time of Return to Sport following Anterior Cruciate Ligament Reconstruction. International Journal of Sports Physical Therapy. 2026;21(4):404–414.