Fear of Reinjury Following Anterior Cruciate Ligament Reconstruction Is Manifested in Muscle Activation Patterns of Single-Leg Side-Hop Landings.
Jonas L Markström, Adam Grinberg, Charlotte K Häger
PMID 34554253WHAT IT FOUND
People with high fear of re-injury after ACL reconstruction showed stiffer muscle activation during single-leg side-hop landings.
They did not show different joint angles or worse self-reported knee function compared to those with low fear. This suggests fear alters how muscles stabilize the knee, not how the joint moves.
Key findings
01High fear of re-injury is associated with higher biceps femoris muscle activation and greater anterior-posterior co-contraction during landing compared to low fear and controls.
02There were no significant differences in joint kinematics between the high-fear and low-fear groups.
03Fear of re-injury was not associated with differences in patient-reported outcomes for knee function, health, or physical activity between the high- and low-fear groups.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study used a single question to classify fear, which may not fully capture the complexity of kinesiophobia. The control group had a significantly higher proportion of females compared to the ACLR groups, which could introduce sex-specific bias in biomechanical outcomes. The time since surgery varied widely (7 to 24 months), making it difficult to apply findings to a specific stage of rehabilitation. The cross-sectional design cannot determine if fear causes the muscle changes or if the muscle changes contribute to fear.
Declared interests
The funders played no role in the design, conduct, or reporting of this study.
The easy way to misread this
Do not assume that a patient's normal range of motion or good self-reported knee function means they are free from fear-related movement deficits. This study shows that high fear manifests as increased muscle co-contraction and stiffness during landing, even when joint angles and patient-reported outcomes appear similar to those with low fear.